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Background: An unmet need exists to reliably predict the risk of intracranial hemorrhage (ICH) in patients with atrial fibrillation (AF) treated with oral anticoagulants (OACs)., Hypothesis: An externally validated model improves ICH risk stratification., Methods: Independent factors associated with ICH were identified by Cox proportional hazard modeling, using pooled data from the GARFIELD-AF (Global Anticoagulant Registry in the FIELD-Atrial Fibrillation) and ORBIT-AF (Outcomes Registry for Better Informed Treatment of Atrial Fibrillation) registries. A predictive model was developed and validated by bootstrap sampling and by independent data from the Danish National Patient Register., Results: In the combined training data set, 284 of 53 878 anticoagulated patients had ICH over a 2-year period (0.31 per 100 person-years; 95% confidence interval [CI]: 0.28-0.35). Independent predictors of ICH included: older age, prior stroke or transient ischemic attack, concomitant antiplatelet (AP) use, and moderate-to-severe chronic kidney disease (CKD). Vitamin K antagonists (VKAs) were associated with a significantly higher risk of ICH compared with non-VKA oral anticoagulants (NOACs) (adjusted hazard ratio: 1.61; 95% CI: 1.25-2.08; p = .0002). The ability of the model to discriminate individuals in the training set with and without ICH was fair (optimism-corrected C-statistic: 0.68; 95% CI: 0.65-0.71) and outperformed three previously published methods. Calibration between predicted and observed ICH probabilities was good in both training and validation data sets., Conclusions: Age, prior ischemic events, concomitant AP therapy, and CKD were important risk factors for ICH in anticoagulated AF patients. Moreover, ICH was more frequent in patients receiving VKA compared to NOAC. The new validated model is a step toward mitigating this potentially lethal complication., (© 2023 The Authors. Clinical Cardiology published by Wiley Periodicals LLC.)

Atrial fibrillation (AF) is one of the strongest risk factors for ischemic stroke, which is a leading cause of disability and death. Given the aging population, increasing prevalence of AF risk factors, and improved survival in those with cardiovascular disease, the number of individuals affected by AF will continue increasing over time. While multiple proven stroke prevention therapies exist, important questions remain about the optimal approach to stroke prevention at the population and individual patient levels. Our report summarizes the National Heart, Lung, and Blood Institute virtual workshop focused on identifying key research opportunities related to stroke prevention in AF. The workshop reviewed major knowledge gaps and identified targeted research opportunities to advance stroke prevention in AF in the following areas: (1) improving risk stratification tools for stroke and intracranial hemorrhage; (2) addressing challenges with oral anticoagulants; and (3) delineating the optimal roles of percutaneous left atrial appendage occlusion and surgical left atrial appendage closure/excision. This report aims to promote innovative, impactful research that will lead to more personalized, effective use of stroke prevention strategies in people with AF.

Background: Cardioversion is common among patients with atrial fibrillation (AF). We hypothesised that novel oral anticoagulants (NOAC) used in clinical practice resulted in similar rates of stroke compared with vitamin K antagonists (VKA) for cardioversion., Methods: Using the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation II, patients with AF who had a cardioversion, follow-up data and an AF diagnosis within 6 months of enrolment were identified retrospectively. Clinical outcomes were compared for patients receiving a NOAC or VKA for 1 year following cardioversion., Results: Among 13 004 patients with AF, 2260 (17%) underwent cardioversion. 1613 met the inclusion criteria for this analysis. At the time of cardioversion, 283 (17.5%) were receiving a VKA and 1330 (82.5%) a NOAC. A transoesophageal echocardiogram (TOE) was performed in 403 (25%) cardioversions. The incidence of stroke/transient ischaemic attack (TIA) at 30 days was the same for patients having (3.04 per 100 patient-years) or not having (3.04 per 100 patient-years) a TOE (p=0.99). There were no differences in the incidence of death (HR 1.19, 95% CI 0.62 to 2.28, p=0.61), cardiovascular hospitalisation (HR 1.02, 95% CI 0.76 to 1.35, p=0.91), stroke/TIA (HR 1.18, 95% CI 0.30 to 4.74, p=0.81) or bleeding-related hospitalisation (HR 1.29, 95% CI 0.66 to 2.52, p=0.45) at 1 year for patients treated with either a NOAC or VKA., Conclusions: Cardioversion was a low-risk procedure for patients treated with NOAC, and there were statistically similar rates of stroke/TIA 30 days after cardioversion as for patients treated with VKA. There were no statically significant differences in death, stroke/TIA or major bleeding at 1 year among patients treated with NOAC compared with VKA after cardioversion., Competing Interests: Competing interests: BJG: member of a Data Safety Monitoring Board for Mount Sinai St Luke's, Boston Scientific, Teva Pharmaceutical Industries, St Jude Medical, Janssen Research & Development, Baxter Healthcare and Cardiovascular Research Foundation; consultant/Advisory Board for Janssen Scientific Affairs, Cipla, Armetheon and Medtronic. MDE: consultant/Advisory Board and grant support from Boehringer Ingelheim, Diachi Sanko, Pfizer, Bristol Myers Squibb and Janssen Scientific Affairs. PRK: consultant for Johnson and Johnson. JAR: research grant from Janssen Pharmaceuticals; research support from Boehringer Ingelheim Pharmaceuticals and GlaxoSmithKline; consultancies with Sanofi, Gilead Sciences, CV Therapeutics, GlaxoSmithKline, Merck & Co, Cardiome Pharma, Boehringer Ingelheim Pharmaceuticals and Medtronic; speakers bureau income from Sanofi and Boehringer Ingelheim Pharmaceuticals. GN: research grant from Janssen; consultant/Advisory Board for Janssen and Daiichi Sankyo. KWM: financial disclosures can be viewed at http://med.stanford.edu/profiles/kenneth-mahaffey. DES: consultant/Advisory Board for Boehringer Ingelheim, Bristol Myers Squibb, Merck, Johnson and Johnson, Pfizer and Medtronic; research grants from Boehringer Ingelheim and Bristol Myers Squibb. JF: consultant/Advisory Board for Janssen Scientific., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

The aim of this study was to quantify time in therapeutic range (TTR) before and after a temporary interruption of warfarin due to an intervention in the Outcomes Registry for Better Informed Treatment of atrial fibrillation (AF). AF patients on warfarin who had a temporary interruption followed by resumption were identified. A nonparametric method for estimating survival functions for interval censored data was used to examine the first therapeutic International Normalized Ratio (INR) after interruption. TTR was compared using Wilcoxon signed rank test. Cox proportional hazards model was used to investigate the association between TTR in the first 3 months after interruption and subsequent outcomes at 3 to 9 months. Of 9,749 AF patients, 71% were on warfarin. Over a median (IQR) follow-up of 2.6 (1.8 to 3.1) y, 33% of patients had a total of 3,022 temporary interruptions. The first therapeutic INR was recorded within 1 week in 35.0% (95% confidence interval 32.6% to 37.4%), 2 weeks in 54.6% (52.2% to 57.0%), 30 days in 70.0% (67.9% to 72.1%) and 90 days in 91.3% (90.0% to 92.5%) of patients. Compared with pre-interruption, TTR 3 months after interruption was significantly lower (61.1% [36.6% to 85.0%] vs 67.6% [50.0% to 81.3%], p <0.0001). A 10 unit increment in the TTR in the first 3 months after interruption was associated with a lower risk of major bleeding [Hazard ratio 0.91 (0.85 to 0.97), p = 0.005]. This association was noted in patients who received bridging anticoagulation, but not in those who did not. In conclusion, temporary interruption of warfarin is common, and nearly half of these patients had subtherapeutic INR after 2 weeks. Lower TTR in the first 3 months after interruption was associated with higher incidence of major bleeding in patients who received bridging anticoagulation., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: The inflammatory biomarker interleukin-6 (IL-6) is associated with mortality in atrial fibrillation (AF)., Objective: To investigate if repeated IL-6 measurements improve the prognostication for stroke or systemic embolism, major bleeding, and mortality in anticoagulated patients with AF., Methods: IL-6 levels by ELISA were measured at study entry and at 2 months in 4830 patients in the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial with 1.8 years median follow-up. In the Randomized Evaluation of Long-Term Anticoagulation Therapy (RE-LY) trial, IL-6 was measured at study entry, 3, 6, and 12 months in 2559 patients with 2.0 years median follow-up. Associations between a second IL-6 measurement and outcomes, adjusted for baseline IL-6, clinical variables, and other cardiovascular biomarkers, were analyzed by Cox regression., Results: Median IL-6 levels were 2.0 ng/L (interquartile range [IQR] 1.30-3.20) and 2.10 ng/L (IQR 1.40-3.40) at the two time-points in ARISTOTLE, and, in RE-LY, 2.5 ng/L (IQR 1.6-4.3), 2.5 ng/L (IQR 1.6-4.2), 2.4 ng/L (IQR 1.6, 3.9), and 2.4 ng/L (IQR 1.5, 3.9), respectively. IL-6 was associated with mortality; hazard ratios per 50% higher IL-6 at 2 or 3 months, respectively, were 1.32 (95% confidence interval, 1.23-1.41; P < .0001) in ARISTOTLE, and 1.11 (1.01-1.22, P = .0290) in RE-LY; with improved C index from 0.74 to 0.76 in ARISTOTLE, but not in the smaller RE-LY cohort. There were no consistent associations with second IL-6 and stroke or systemic embolism, or major bleeding., Conclusions: Persistent systemic inflammatory activity, assessed by repeated IL-6 measurements, is associated with mortality independent of established clinical risk factors and other strong cardiovascular biomarkers in anticoagulated patients with AF., (© 2020 The Authors. Journal of Thrombosis and Haemostasis published by Wiley Periodicals LLC on behalf of International Society on Thrombosis and Haemostasis.)

While oral anticoagulation is a cornerstone of stroke prevention therapy in atrial fibrillation (AF), few studies have evaluated comparative discontinuation rates in clinical practice. The objective of this study is to evaluate discontinuation rates among patients on warfarin and direct oral anticoagulants (DOACs) in clinical practice., Methods: The ORBIT-AF II Registry enrolled 10,005 total AF patients with a CHA 2 DS 2 VASc score of ≥2 on warfarin or DOACs from 235 clinical practices across the US from February 13, 2013 and July 12, 2017. Descriptive statistics and multivariable Cox regression modeling were used to describe baseline characteristics and predictors of discontinuation. Unadjusted and adjusted discontinuation rates and 95% confidence intervals (CI) were calculated using Cox proportional hazards models and propensity score adjustment, respectively., Results: At baseline, 16.4% (N = 1642/10,005) were treated with warfarin, 83.6% (N = 8363/10,005) with DOACs and 1498/10,005 patients (15.0%) discontinued therapy [warfarin = 236/1642 (14.4%) vs DOACs = 1262/8363 (15.1%)]. At 6 and 12 months respectively, among 7049 patients with a new diagnosis of AF within 6 months, adjusted discontinuation rates for warfarin versus DOACs were as follows: [6 months: 7.9%, 95%CI (6.8%-9.0%) vs 9.6% (8.4%-10.7%), P = .16]; [12 months: 12.7% (11.0%-14.3%) vs 15.3% (13.6%-16.9%), P = .02)]. Patients who discontinued therapy with warfarin or DOACs had higher risk of adverse clinical outcomes including: all-cause mortality and cardiovascular death (CV) than those who continued treatment., Conclusion: In a community based AF cohort, adjusted rates of discontinuation at 12-months were higher in DOAC-treated versus VKA-treated patients. Discontinuation of oral anticoagulation was associated with increased absolute risk of all-cause mortality and CV death., Clinical Trial Registration: URL:https://clinicaltrials.gov. Unique Identifier: NCT01701817., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Studies evaluating the effects of atrial fibrillation (AF) catheter ablation versus antiarrhythmic therapy on outcomes have shown mixed results. In addition, guidelines recommend continuing oral anticoagulation (OAC) after ablation for those at risk of stroke, but real-world data are lacking., Methods: We evaluated outcomes including death, myocardial infarction, stroke or systemic embolism, intracranial bleeding, major bleeding, and hospitalization in patients undergoing AF ablation compared with a propensity score matched cohort of patients treated with anti-arrhythmic medications only in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation registries. Cox proportional hazards regression was performed to evaluate the association between AF ablation and outcomes. We then evaluated patterns of treatment with OAC among AF ablation patients., Results: Among 21 595 patients, 1190 (6%) underwent de novo AF ablation. Our propensity score-matched cohort included 1087 patients who underwent AF ablation matched 1:1 with 1087 patients treated with antiarrhythmic medications only. There were no significant differences in the risk of all-cause and cardiovascular death, and most other major adverse cardiovascular and neurological events. AF catheter ablation was associated with an increased risk of all-cause hospitalization during follow-up (hazard ratio, 1.24 [95% CI, 1.05-1.46]), particularly in the first 3 months (the standard blanking period) after the procedure. Among those who underwent AF ablation with a CHA 2 DS 2 VASc score ≥2 for men and ≥3 for women, 23% had OAC discontinued after ablation. Among those who discontinued OAC, the median time to discontinuation was 6.2 months., Conclusions: In this large US national registry, we found no difference in adjusted rates of cardiovascular or all-cause death between patients treated with AF catheter ablation and antiarrhythmic medications only. Notably, discontinuation of OAC after ablation remains relatively common despite guideline recommendations for continued stroke prevention therapy in patients at risk of stroke.

Background Patient satisfaction with therapy is an important metric of care quality and has been associated with greater medication persistence. We evaluated the association of patient satisfaction with warfarin therapy to other metrics of anticoagulation care quality and clinical outcomes among patients with atrial fibrillation ( AF ). Methods and Results Using data from the ORBIT - AF (Outcomes Registry for Better Informed Treatment of Atrial Fibrillation) registry, patients were identified with AF who were taking warfarin and had completed an Anti-Clot Treatment Scale ( ACTS ) questionnaire, a validated metric of patient-reported burden and benefit of oral anticoagulation. Multivariate regressions were used to determine association of ACTS burden and benefit scores with time in therapeutic international normalized ratio range ( TTR ; both ≥75% and ≥60%), warfarin discontinuation, and clinical outcomes (death, stroke, major bleed, and all-cause hospitalization). Among 1514 patients with AF on warfarin therapy (75±10 years; 42% women; CHA 2 DS 2 - VAS c 3.9±1.7), those most burdened with warfarin therapy were younger and more likely to be women, have paroxysmal AF , and to be treated with antiarrhythmic drugs. After adjustment for covariates, ACTS burden scores were independent of TTR ( TTR ≥75%: odds ratio, 1.01 [95% CI , 0.99-1.03]; TTR ≥60%: odds ratio, 1.01 [95% CI , 0.98-1.05]), warfarin discontinuation (odds ratio, 0.99; 95% CI , 0.97-1.01), or clinical outcomes. ACTS benefit scores were also not associated with TTR , warfarin discontinuation, or clinical outcomes. Conclusions In a large registry of patients with AF taking warfarin, ACTS scores provided independent information beyond other traditional metrics of oral anticoagulation care quality and identified patient groups at high risk for dissatisfaction with warfarin therapy.

Objectives: Compare the effect of apixaban and warfarin on coagulation and primary haemostasis biomarkers in atrial fibrillation (AF)., Methods: The biomarker substudy from the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation trial included 4850 patients with AF randomised to treatment with apixaban or warfarin. Sixty per cent of patients used vitamin K antagonist (VKA) within 7 days before randomisation. Prothrombin fragment 1+2 (F1+2), D-dimer, soluble CD40 ligand (sCD40L) and von Willebrand factor (vWF) antigen were analysed at randomisation and after 2 months of study treatment., Results: In patients not on VKA treatment at randomisation, F1+2 and D-dimer levels were decreased by 25% and 23%, respectively, with apixaban, and by 59% and 38%, respectively, with warfarin (p<0.0001 for treatment differences for both). In patients on VKA at randomisation, F1+2 and D-dimer levels increased by 41% and 10%, respectively, with apixaban and decreased by 37% and 11%, respectively, with warfarin (p<0.0001 for treatment differences for both). sCD40L levels were slightly increased at 2 months, regardless of VKA or randomised treatment. Apixaban and warfarin also both reduced vWF antigen regardless of VKA treatment. The efficacy (stroke) and safety (bleeding) of apixaban compared with warfarin was similar irrespectively of biomarker levels at 2 months., Conclusions: Treatment with apixaban compared with warfarin for stroke prevention in patients with AF was associated with less reduction in thrombin generation and fibrin turnover. This effect of apixaban could contribute to the clinical results where apixaban was superior to warfarin both in stroke prevention and in reducing bleeding risk., Trial Registration Number: NCT00412984., Competing Interests: Competing interests: CC: lecture fees from Boehringer Ingelheim, Bristol-Myers Squibb, CSL Behring, Novartis. LW: institutional research grants from AstraZeneca, Boehringer Ingelheim, Bristol-Myers Squibb/Pfizer, GlaxoSmithKline, Merck & Co, Roche Diagnostics; holds two patents involving GDF-15. UA: institutional research grant from Bristol-Myers Squibb/Pfizer. JHA: research grants from Boehringer Ingelheim, Bristol-Myers Squibb, CSL Behring, FDA, NIH, CryoLife, Tenax Therapeutics, VoluMetrix; honoraria from Bristol-Myers Squibb, CSL Behring, Janssen Pharmaceuticals, Merck, NovoNordisk Pharmaceuticals, Pfizer, VA Cooperative Studies Program, Zafgen; consultancy/advisory board fees from AbbVie, Bristol-Myers Squibb, CSL Behring, Janssen Pharmaceuticals, Merck, NovoNordisk Pharmaceuticals, Pfizer, Portola Pharmaceuticals, VA Cooperative Studies Program, Zafgen. MA: speaker’s bureau from Pfizer; honoraria from Pfizer; consultant/advisory board from Bristol-Myers Squibb, Daiichi Sankyo, Bayer, Boehringer Ingelheim, Pfizer. RDC: research grants from Bayer, Bristol-Myers Squibb/Pfizer, Daiichi Sankyo; speaker’s bureau from Daiichi Sankyo, Bristol-Myers Squibb/Pfizer; honoraria from Daiichi Sankyo, Bayer, Bristol-Myers Squibb/Pfizer; consultant/advisory board from Bayer, Daiichi Sankyo. BJG: data safety monitoring board from Boston Scientific, Cardiovascular Research Foundation, Duke Clinical Research Institute, Duke University, Icahn School of Medicine at Mount Sinai, Janssen Research & Development, Kowa Research Institute, Medtronic, Mount Sinai St Lukes, Teva Pharmaceutical Industries, Myokardia; consultancy fees from Coretherapix SLU, Janssen Scientific Affairs, Sirtex Medical. CBG: research grants from Armetheon, AstraZeneca, Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Daiichi Sankyo; Duke Clinical Research Institute, FDA, GlaxoSmithKline, Janssen Pharmaceuticals, Medtronic Foundation, Novartis, Pfizer; consultancy/advisory board fees from AbbVie, Armetheon, AstraZeneca, Bayer, Boehringer Ingelheim, Boston Scientific, Bristol-Myers Squibb, Daiichi Sankyo, Gilead Sciences, GlaxoSmithKline, Janssen Pharmaceuticals, Medscape, Medtronic, Merck, NIH, Novartis, Pfizer, Rho Pharmaceuticals, Sirtex, Verseon. SH: honoraria from AstraZeneca, Bayer, Boehringer Ingelheim, Pfizer, Bristol-Myers Squibb, Merck, Sanofi. MH: former employee of and has stock ownership in Bristol-Myers Squibb. KH: speaker’s bureau from Daiichi Sankyo. EMH: research grants from Janssen Pharmaceuticals; honoraria from Bristol-Myers Squibb/Pfizer, Boehringer Ingelheim; consultancy/advisory board fees from Bayer, Boehringer Ingelheim, Bristol-Myers Squibb/Pfizer, Medtronic, Portola. RDL: research grants from Amgen, Bristol-Myers Squibb/Pfizer, GlaxoSmithKline, Medtronic PLC, Sanofi-Aventis; consultant/advisory board fees from Bristol-Myers Squibb/Pfizer, Bayer, Boehringer Ingelheim. B-HO: grant and personal fees from Novartis. AS: institutional research grants from AstraZeneca, Boehringer Ingelheim, Bristol-Myers Squibb/Pfizer, Roche Diagnostics, GlaxoSmithKline; consultancy fees from Olink Proteomics., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Patients with atrial fibrillation (AF) often have multi-morbidity, defined as ≥3 comorbid conditions. Multi-morbidity is associated with polypharmacy, adverse events, and frailty potentially altering response to anticoagulation. We sought to describe the prevalence of multi-morbidity among older patients with AF and determine the association between multi-morbidity, clinical outcomes, and the efficacy and safety of apixaban compared with warfarin., Methods: In this post-hoc subgroup analysis of the ARISTOTLE trial, we studied enrolled patients age ≥ 55 years (n = 16,800). Patients were categorized by the number of comorbid conditions at baseline: no multi-morbidity (0-2 comorbid conditions), moderate multi-morbidity (3-5 comorbid conditions), and high multi-morbidity (≥6 comorbid conditions). Association between multi-morbidity and clinical outcomes were analyzed by treatment with a median follow-up of 1.8 (1.3-2.3) years., Results: Multi-morbidity was present in 64% (n = 10,713) of patients; 51% (n = 8491) had moderate multi-morbidity, 13% (n = 2222) had high multi-morbidity, and 36% (n = 6087) had no multi-morbidity. Compared with the no multi-morbidity group, the high multi-morbidity group was older (74 vs 69 years), took twice as many medications (10 vs 5), and had higher CHA 2 DS 2 -VASc scores (4.9 vs 2.7) (all P < .001). Adjusted rates per 100 patient-years for stroke/systemic embolism, death, and major bleeding increased with multi-morbidity (Reference no multi-morbidity; moderate multi-morbidity 1.42 [1.24-1.64] and high multi-morbidity 1.92 [1.59-2.31]), with no interaction in relation to efficacy or safety of apixaban., Conclusions: Multi-morbidity is prevalent among the population with AF; efficacy and safety of apixaban is preserved in this subgroup supporting extension of trial results to the most complex AF patients., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background Chronic kidney disease ( CKD ) is a common comorbidity in patients with atrial fibrillation. The presence of CKD complicates drug selection for stroke prevention and rhythm control. Methods and Results Patients enrolled in ORBIT AF (Outcomes Registry for Better Informed Treatment of Atrial Fibrillation) with baseline renal function and follow-up data were included (N=9019). CKD was defined as an estimated creatinine clearance <60 mL /min. Patient characteristics were compared by CKD status, and Cox proportional hazards modeling was used to examine the association between oral anticoagulant ( OAC ) use and outcomes and antiarrhythmic drug use and outcomes stratified by CKD stages. At enrollment, 3490 (39%) patients had an estimated creatinine clearance <60 mL /min. Patients with CKD were older and had higher CHA 2 DS 2 VAS c and Anticoagulant and Risk Factors in Atrial Fibrillation (ATRIA) scores. A rhythm control strategy was selected less frequently in patients with CKD , while OAC use was lower among Stage IV and V CKD patients. After adjustment, no significant interaction was noted for OAC and CKD on all-cause mortality ( P=0.5442) or cardiovascular death ( P=0.1233), although a trend for increased major bleeding ( P=0.0608) and stroke, systemic embolism or transient ischemic attack ( P=0.0671) was observed. No interaction was noted for antiarrhythmic drug use and CKD status on all-cause mortality ( P=0.9706), or stroke, systemic embolism or transient ischemic attack ( P=0.4218). Conclusions Patients with atrial fibrillation and CKD are less likely to be treated with rhythm control. Patients with advanced CKD are less likely to receive OAC . Finally, outcomes with OAC in patients with advanced CKD may be materially different with higher rates of both bleeding and stroke.

Background: Bleeding is commonly cited as a reason for stopping oral anticoagulants (OACs). Whether minor bleeding events (nuisance bleeding, NB) in patients with atrial fibrillation on OACs are associated with OAC discontinuation, major bleeding, and stroke/systemic embolism (SSE) is unknown., Methods: Within the ORBIT-AF prospective, outpatient registry (Outcomes Registry for Better Informed Treatment of Atrial Fibrillation), we identified 6771 patients ≥18 years of age at 172 sites with atrial fibrillation and eligible follow-up visits. NB was ascertained from the medical record and was defined as minor bleeding that did not require medical attention (eg, bruising, hemorrhoidal bleeding). We used multivariable pooled logistic regression modeling to evaluate the associations between NB and major bleeding and SSE in the 180 days after documentation of NB. Our unit of analysis was the patient visit, occurring at ≈6-month intervals for a median of 1.5 years following enrollment. Changes in anticoagulation treatment satisfaction after NB were examined descriptively in a subset of patients., Results: The median age of the overall population was 75.0 (interquartile range, 67.0-81.0); 90.0% were white and 42.5% were female. Among 6771 patients (18 560 visits), n=1357 (20.0%) had documented NB, for an incidence rate of 14.8 events per 100 person-years. Over 96.4% of patients remained on OAC therapy after the NB event. Overall, 287 (4.3%) patients experienced major bleeding and 64 (0.96%) had a SSE event during follow-up. NB was not associated with a significant increased risk of major bleeding over 6 months in models adjusting for the ATRIA bleeding score (Anticoagulation and Risk Factors in Atrial Fibrillation) (odds ratio, 1.04; 95% confidence interval, 0.68-1.60; P=0.86). NB was also not associated with increased SSE risk over 6 months in models adjusting for the CHA 2 DS 2 -VASc risk score (odds ratio, 1.24; 95% confidence interval, 0.53-2.91; P=0.62)., Conclusions: NB is common among patients with atrial fibrillation on OACs. However, NB was not associated with a higher risk of major bleeding or SSE over the next 6 months, suggesting its occurrence should not lead to changes in anticoagulation treatment strategies in OAC-treated patients., Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01165710.

Background Current American College of Cardiology/American Heart Association guidelines suggest that for patients with atrial fibrillation who are at low risk for stroke (CHA 2 DS 2 VASc=1) (or women with CHA 2 DS 2 VASc=2) a variety of treatment strategies may be considered. However, in clinical practice, patterns of treatment in these "low-risk" patients are not well described. The objective of this analysis is to define thromboembolic event rates and to describe treatment patterns in patients with low-risk CHA 2 DS 2 VASc scores. Methods and Results We compared characteristics, treatment strategies, and outcomes among patients with a CHA 2 DS 2 VASc=0, CHA 2 DS 2 VASc=1, females with a CHA 2 DS 2 VASc=2, and CHA 2 DS 2 VASc ≥2 in ORBIT-AF (Outcomes Registry for Better Informed Treatment of Atrial Fibrillation) I & II. Compared with CHA 2 DS 2 VASc ≥2 patients (84.2%), those with a CHA 2 DS 2 VASc=0 (60.3%), 1 (69.9%), and females with a CHA 2 DS 2 VASc score=2 (72.4%) were significantly less often treated with oral anticoagulation ( P<0.0001). Stroke rates were low overall and ranged from 0 per 100 patient-years in those with CHA 2 DS 2 VASc=0, 0.8 (95% confidence interval [CI] [0.5-1.2]) in those with CHA 2 DS 2 VASc=1, 0.8 (95% CI [0.4-1.6]) in females with a CHA 2 DS 2 VASc score=2, and 1.7 (95% CI [1.6-1.9]) in CHA 2 DS 2 VASc ≥2. All-cause mortality (per 100 patient-years) was highest in females with a CHA 2 DS 2 VASc score=2 (1.4) (95% CI [0.8-2.3]), compared with patients with a CHA 2 DS 2 VASc=0 (0.2) (95% CI [0.1-1.0]), and CHA 2 DS 2 VASc=1 (1.0) (95% CI [0.7-1.4]), but lower than patients with a CHA 2 DS 2 VASc ≥2 (5.7) (95% CI [5.4-6.0]). Conclusion The majority of CHA 2 DS 2 VASc=0-1 patients are treated with oral anticoagulation. In addition, the absolute risks of death and stroke/transient ischemic attack were low among both male and females CHA 2 DS 2 VASc=0-1 as well as among females with a CHA 2 DS 2 VASc score=2. Clinical Trial Registration URL: http://www.clinicaltrials.gov . Unique identifier: NCT01701817.

Background: Mineralocorticoid receptor antagonist (MRA) therapy may be beneficial to patients with atrial fibrillation (AF), but little is known about their use in patients with AF and subsequent outcomes., Methods and Results: In order to better understand MRA use and subsequent outcomes, we performed a retrospective cohort study of the contemporary ORBIT-AF (Outcomes Registry for Better Informed Treatment of Atrial Fibrillation) registry. AF progression and cardiovascular outcomes were compared using propensity-matched Cox proportional hazards modeling according to MRA use at baseline and new MRA use at follow-up versus patients with no MRA use. Among 7012 patients with nonpermanent AF, 320 patients were taking MRA at enrollment, and 416 patients initiated MRA use during follow-up. The mean patient age was 72.5 years, 56.3% were men, and 70.4% had paroxysmal AF. Among all patients taking MRAs, 434 (59.0%) had heart failure, 655 (89.0%) had hypertension, and 380 (51.6%) had both. After adjustment, new MRA use was not associated with reduced AF progression (hazard ratio, 1.18; 95% confidence interval, 0.88-1.58; P =0.27) but showed a trend towards lower risk of stroke, transient ischemic attack, or systemic embolism (hazard ratio, 0.17; 95% confidence interval, 0.02-1.23; P =0.08). Results were similar for a comparison of new MRA users and baseline MRA users compared with nonusers., Conclusions: In community-based outpatients with AF, the majority of MRA use was for heart failure and hypertension. MRA use also trended towards lower adjusted stroke risk. Future studies should test the hypothesis that MRA use may decrease the risk of stroke in patients with AF., (© 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Background: Cancer is associated with a prothrombotic state and increases the risk of thrombotic events in patients with atrial fibrillation. We described the clinical characteristics and outcomes and assessed the safety and efficacy of apixaban versus warfarin in patients with atrial fibrillation and cancer in the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial., Methods: The association between cancer and clinical outcomes was assessed using Cox regression models. At baseline, 1236 patients (6.8%) had a history of cancer; 12.7% had active cancer, and 87.3% had remote cancer., Results: There were no significant associations between history of cancer and stroke/systemic embolism, major bleeding, or death. The effect of apixaban versus warfarin for the prevention of stroke/systemic embolism was consistent among patients with a history of cancer (event/100 patient-years = 1.4 vs 1.2; hazard ratio [HR], 1.09; 95% confidence interval [CI], 0.53-2.26) and no cancer (1.3 vs 1.6; HR, 0.77; 95% CI, 0.64-0.93) (P interaction = .37). The safety and efficacy of apixaban versus warfarin were preserved among patients with and without active cancer. Apixaban was associated with a greater benefit for the composite of stroke/systemic embolism, myocardial infarction, and death in active cancer (HR, 0.30; 95% CI, 0.11-0.83) versus without cancer (HR, 0.86; 95% CI, 0.78-0.95), but not in remote cancer (HR, 1.46; 95% CI, 1.01-2.10) (interaction P = .0028)., Conclusions: Cancer was not associated with a higher risk of stroke. The superior efficacy and safety of apixaban versus warfarin were consistent in patients with and without cancer. Our positive findings regarding apixaban use in patients with atrial fibrillation and cancer are exploratory and promising, but warrant further evaluation., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Oral anticoagulation (OAC) therapy is associated with increased periprocedural risks after cardiac implantable electronic device (CIED) implantation. Patterns of anticoagulation management involving non-vitamin K antagonist oral anticoagulants (NOACs) have not been characterized., Hypothesis: Anticoagulation strategies and outcomes differ by anticoagulant type in patients undergoing CIED implantation., Methods: Using the nationwide Outcomes Registry for Better Informed Treatment of Atrial Fibrillation, we assessed how atrial fibrillation (AF) patients undergoing CIED implantation were cared for and their subsequent outcomes. Outcomes were compared by oral anticoagulant therapy (none, warfarin, or NOAC) as well as by anticoagulation interruption status., Results: Among 9129 AF patients, 416 (5%) underwent CIED implantation during a median follow-up of 30 months (interquartile range, 24-36). Of these, 60 (14%) had implantation on a NOAC. Relative to warfarin therapy, those on a NOAC were younger (70.5 years [range, 65-77.5 years] vs 77 years [range, 70-82 years]), had less valvular heart disease (15.0% vs 31.3%), higher creatinine clearance (67.3 [range, 59.7-99.0] vs 65.8 [range, 50.0-91.6]), were more likely to have persistent AF (26.7% vs 22.9%), and use concomitant aspirin (51.7% vs 35.2%). OAC therapy was commonly interrupted for CIED in 64% (n = 183 of 284) of warfarin patients and 65% (n = 39 of 60) of NOAC patients. Many interrupted patients received intravenous bridging anticoagulation: 33/183 (18%) interrupted warfarin and 4/39 (10%) interrupted NOAC patients. Thirty-day periprocedure bleeding and stroke adverse events were infrequent., Conclusions: Management of anticoagulation among AF patients undergoing CIED implantation is highly variable, with OAC being interrupted in more than half of both warfarin- and NOAC-treated patients. Bleeding and stroke events were infrequent in both warfarin and NOAC-treated patients., (© 2017 The Authors. Clinical Cardiology published by Wiley Periodicals, Inc.)

Aims: The presence of cancer can complicate treatment choices for patients with atrial fibrillation (AF) increasing both the risk of thrombotic and bleeding events., Methods and Results: Using data from Outcomes Registry for Better Informed Treatment of Atrial Fibrillation, we aimed to characterize AF patients with cancer, to describe their management and to assess the association between cancer and cardiovascular (CV) outcomes. Among 9749 patients, 23.8% had history of cancer (57% solid malignancy, 1.3% leukaemia, 3.3% lymphoma, 40% other type, and 2.2% metastatic cancer). Patients with history of cancer were older, more likely to have CV disease, CV risk factors, and prior gastrointestinal bleeding. No difference in antiarrhythmic and antithrombotic therapy was observed between those with and without cancer. Patients with history of cancer had a significantly higher risk of death (7.8 vs. 4.9 deaths per 100 patient-years follow-up, P = 0.0003) mainly driven by non-CV death (4.2 vs. 2.4 per 100 patient-years follow-up; P = 0.0004) and higher risk of major bleeding (5.1 vs. 3.5 per 100 patient-years follow-up; P = 0.02) compared with non-cancer patients; no differences were observed in risks of strokes/non-central nervous system embolism (1.96 vs. 1.48, P = 0.74) and CV death (2.89 vs. 2.07, P = 0.35) between the two groups., Conclusion: A history of cancer is common among AF patients with up to one in four patients having both. Antithrombotic therapy, rates of cerebrovascular accident, other thrombotic events and cardiac death were similar in AF patients with or without a history of cancer. Patients with cancer, however, were at higher risk of major bleeding and non-CV death., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.)

Background: Cardiac biomarkers are independent risk markers in atrial fibrillation, and the novel biomarker-based ABC stroke score (age, biomarkers, and clinical history of prior stroke) was recently shown to improve the prediction of stroke risk in patients with atrial fibrillation. Our aim was to investigate the short-term variability of the cardiac biomarkers and evaluate whether the ABC stroke risk score provides a stable short-term risk estimate., Methods and Results: According to the study protocol, samples were obtained at entry and also at 2 months in 4796 patients with atrial fibrillation followed for a median of 1.8 years in the ARISTOTLE (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation) trial. Cardiac troponin I, cardiac troponin T, and N-terminal pro-B-type natriuretic peptide were measured with high-sensitivity immunoassays. Associations with outcomes were evaluated by Cox regression. C indices and calibration plots were used to evaluate the ABC stroke score at 2 months. The average changes in biomarker levels during 2 months were small (median change cardiac troponin T +2.8%, troponin I +2.0%, and N-terminal pro-B-type natriuretic peptide +13.5%) and within-subject correlation was high (all ≥0.82). Repeated measurement of cardiac biomarkers provided some incremental prognostic value for mortality but not for stroke when combined with clinical risk factors and baseline levels of the biomarkers. Based on 8702 person-years of follow-up and 96 stroke/systemic embolic events, the ABC stroke score at 2 months achieved a similar C index of 0.70 (95% CI, 0.65-0.76) as compared with 0.70 (95% CI, 0.65-0.75) at baseline. The ABC stroke score remained well calibrated using predefined risk classes., Conclusions: In patients with stable atrial fibrillation, the variability of the cardiac biomarkers and the biomarker-based ABC stroke score during 2 months are small. The prognostic information by the ABC stroke score remains consistent and well calibrated with similar good predictive performance if patients are retested after 2 months., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00412984., (© 2017 The Authors and Bristol Myers Squibb Co. Published on behalf of the American Heart Association, Inc., by Wiley.)

Objective: We describe the incidence, location and management of non-major bleeding, and assess the association between non-major bleeding and clinical outcomes in patients with atrial fibrillation (AF) receiving anticoagulation therapy enrolled in Apixaban for Reduction in Stroke and other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE)., Methods: We included patients who received ≥1 dose of study drug (n=18 140). Non-major bleeding was defined as the first bleeding event considered to be clinically relevant non-major (CRNM) or minor bleeding, and not preceded by a major bleeding event., Results: Non-major bleeding was three times more common than major bleeding (12.1% vs 3.8%). Like major bleeding, non-major bleeding was less frequent with apixaban (6.4 per 100 patient-years) than warfarin (9.4 per 100 patient-years) (adjusted HR 0.69, 95% CI 0.63 to 0.75). The most frequent sites of non-major bleeding were haematuria (16.4%), epistaxis (14.8%), gastrointestinal (13.3%), haematoma (11.5%) and bruising/ecchymosis (10.1%). Medical or surgical intervention was similar among patients with non-major bleeding on warfarin versus apixaban (24.7% vs 24.5%). A change in antithrombotic therapy (58.6% vs 50.0%) and permanent study drug discontinuation (5.1% (61) vs 3.6% (30), p=0.10) was numerically higher with warfarin than apixaban. CRNM bleeding was independently associated with an increased risk of overall death (adjusted HR 1.70, 95% CI 1.32 to 2.18) and subsequent major bleeding (adjusted HR 2.18, 95% CI 1.56 to 3.04)., Conclusions: In ARISTOTLE, non-major bleeding was common and substantially less frequent with apixaban than with warfarin. CRNM bleeding was independently associated with a higher risk of death and subsequent major bleeding. Our results highlight the importance of any severity of bleeding in patients with AF treated with anticoagulation therapy and suggest that non-major bleeding, including minor bleeding, might not be minor., Trial Registration Number: NCT00412984; post-results., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

The choice of oral anticoagulant (OAC) for patients with atrial fibrillation (AF) may be influenced by individual clinical features or by patterns of risk factors and comorbidities. We reviewed analyses of subgroups of patients from trials of vitamin K antagonists vs. non-vitamin K oral anticoagulants (NOACs) for stroke prevention in AF with the aim to identify patient groups who might benefit from a particular OAC more than from another. In addition, we discuss the timing of initiation of anticoagulation. In the second of a two-part review, we discuss the use of NOAC for stroke prevention in the following subgroups of patients with AF: (vii) secondary stroke prevention in patients after stroke or transient ischaemic attack (TIA), (viii) patients with acute stroke requiring thrombolysis or thrombectomy, (ix) those initiating or restarting OAC treatment after stroke or TIA, (x) those with renal impairment on dialysis, (xi) the elderly, (xii) those at high risk of gastrointestinal bleeding, and (xiii) those with hypertension. In addition, we discuss adherence and compliance. Finally, we present a summary of treatment suggestions. In specific subgroups of patients with AF, evidence supports the use of particular NOACs and/or particular doses of anticoagulant. The appropriate choice of treatment for these subgroups will help to promote optimal clinical outcomes., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.)

Patients with atrial fibrillation (AF) have a high risk of stroke and mortality, which can be considerably reduced by oral anticoagulants (OAC). Recently, four non-vitamin-K oral anticoagulants (NOACs) were compared with warfarin in large randomized trials for the prevention of stroke and systemic embolism. Today's clinician is faced with the difficult task of selecting a suitable OAC for a patient with a particular clinical profile or a particular pattern of risk factors and concomitant diseases. We reviewed analyses of subgroups of patients from trials of vitamin K antagonists vs. NOACs for stroke prevention in AF with the aim to identify patient groups who might benefit from a particular OAC more than from another. In the first of a two-part review, we discuss the choice of NOAC for stroke prevention in the following subgroups of patients with AF: (i) stable coronary artery disease or peripheral artery disease, including percutaneous coronary intervention with stenting and triple therapy; (ii) cardioversion, ablation and anti-arrhythmic drug therapy; (iii) mechanical valves and rheumatic valve disease, (iv) patients with time in therapeutic range of >70% on warfarin; (v) patients with a single stroke risk factor (CHA2DS2VASc score of 1 in males, 2 in females); and (vi) patients with a single first episode of paroxysmal AF. Although there are no major differences in terms of efficacy and safety between the NOACs for some clinical scenarios, in others we are able to suggest that particular drugs and/or doses be prioritized for anticoagulation., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.)

Background: Patients with atrial fibrillation (AF) are prone to cardiovascular events and anticoagulation-related bleeding complications. We hypothesized that patients with anemia are at increased risk for these outcomes., Methods: We performed a post hoc analysis of the ARISTOTLE trial, which included >18,000 patients with AF randomized to warfarin (target international normalized ratio, 2.0-3.0) or apixaban 5 mg twice daily. Multivariable Cox regression analysis was used to determine if anemia (defined as hemoglobin <13.0 in men and <12.0 g/dL in women) was associated with future stroke, major bleeding, or mortality., Results: Anemia was present at baseline in 12.6% of the ARISTOTLE population. Patients with anemia were older, had higher mean CHADS 2 and HAS-BLED scores, and were more likely to have experienced previous bleeding events. Anemia was associated with major bleeding (adjusted hazard ratio [HR], 1.92; 95% CI, 1.62-2.28; P<.0001) and all-cause mortality (adjusted HR, 1.68; 95% CI, 1.46-1.93; P<.0001) but not stroke or systemic embolism (adjusted HR, 0.92; 95% CI, 0.70-1.21). The benefits of apixaban compared with warfarin on the rates of stroke, mortality, and bleeding events were consistent in patients with and without anemia., Conclusions: Chronic anemia is associated with a higher incidence of bleeding complications and mortality, but not of stroke, in anticoagulated patients with AF. Apixaban is an attractive anticoagulant for stroke prevention in patients with AF with or without anemia., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The purpose of this study is to assess incidence and risk factors for severe renal dysfunction in patients requiring oral anticoagulation to help guide initial drug choice and provide a rational basis for interval monitoring of renal function for patients prescribed non-vitamin K oral anticoagulants., Methods: Patients on warfarin for atrial fibrillation or venous thromboembolism were consecutively enrolled from January 2007 to December 2010. Baseline kidney function was assessed, and patients were followed to their first decline of kidney function to creatinine clearance<30 mL/min. Multivariate regression assessed independent risk factors for the primary outcome. Severe renal impairment based on baseline kidney function was assessed by Kaplan-Meier analyses., Results: Of 787 patients identified, 34 were excluded for baseline CrCl <30 mL/min. The mean age was 71 years, and 74% and 31% had hypertension and diabetes mellitus, respectively. At baseline, 23% (n=174) had moderate chronic kidney disease (CKD) (CrCl 30-59mL/min), whereas 31% had mild CKD (CrCl 60-89mL/min). Severe renal impairment occurred in 92 patients (12%), 25% of which was seen within 5.3 months. Of those with baseline stage 3 CKD, 37% developed severe renal impairment. Stage 3 CKD conferred a 14-fold increased risk in the development of severe renal dysfunction (odds ratio 14.5, 95% CI 6.7-31.3, P<.001). Coronary artery disease was also associated with severe renal impairment (odds ratio 2.2, 95% CI 1.3-3.8, P=.004)., Conclusions: Acute and chronic renal dysfunction is common among individuals requiring long-term anticoagulant therapy. Patients with moderate chronic kidney disease and coronary artery disease are at the highest short-term risk of developing severe renal impairment. More frequent monitoring of these patients is warranted., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Statin pretreatment has been associated with reduced infarct volume in nonlacunar strokes. The effect of statins on functional outcomes of strokes related to atrial fibrillation (AF) is unknown. We aimed to define the influence of prestroke statin use on functional outcome in AF., Methods: We assembled a cohort of consecutive ischemic stroke patients from 2006 to 2010. All patients underwent CT or MRI and were adjudicated by site investigators. AF was confirmed by electrocardiogram in 100% of patients. Site neurologists blinded to the study hypothesis affirmed the type of stroke and assessed the severity of disability at the time of hospital discharge. The frequency of death at 30-days was calculated., Results: Ischemic stroke (n=1030) resulted in a severe neurological deficit or death (modified Rankin scale ≥4) at 30days in 711 patients (69%). Using multivariable logistic regression models adjusting for factors associated with statin treatment and factors associated with functional outcome, prestroke statin use was associated with a 32% reduction in frequency of severe stroke (odds ratio [OR], 0.68; 95% confidence interval [CI], 0.50-0.92; P=0.011). Other independent factors associated with severe stroke included older age, female sex, non-White race, diabetes mellitus, prior ischemic stroke, prior venous thromboembolism, and dementia., Conclusion: Ischemic strokes in AF are associated with high mortality and morbidity. Statin use at time of stroke onset among patients with AF was associated in this study with less severe stroke and warrant validation., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Background: Atrial fibrillation is associated with increased but variable risk of stroke. Our aim was to validate the recently developed biomarker-based ABC (age, biomarkers [high-sensitivity troponin and N-terminal fragment B-type natriuretic peptide], and clinical history of prior stroke/transient ischemic attack)-stroke risk score and compare its performance with the CHA 2 DS 2 VASc and ATRIA (Anticoagulation and Risk Factors in Atrial Fibrillation) risk scores., Methods: The ABC-stroke score includes age, biomarkers (N-terminal fragment B-type natriuretic peptide and high-sensitivity cardiac troponin), and clinical history (prior stroke). This validation was based on 8356 patients, 16 137 person-years of follow-up, and 219 adjudicated stroke or systemic embolic events in anticoagulated patients with atrial fibrillation in the RE-LY study (Randomized Evaluation of Long-Term Anticoagulation Therapy). Levels of N-terminal fragment B-type natriuretic peptide, high-sensitivity cardiac troponin T (hs-cTnT), and high-sensitivity cardiac troponin I (hs-cTnI) were determined in plasma samples obtained at study entry., Results: The ABC-stroke score was well calibrated with 0.76 stroke/systemic embolic events per 100 person-years in the predefined low (<1%/y) risk group, 1.48 in the medium (1%-2%/y) risk group, and 2.60 in the high (>2%/y) risk group for the ABC-stroke score with hs-cTnT. Hazard ratios for stroke/systemic embolic events were 1.95 for medium- versus low-risk groups, and 3.44 for high- versus low-risk groups. ABC-stroke score achieved C indices of 0.65 with both hs-cTnT and hs-cTnI, in comparison with 0.60 for CHA 2 DS 2 VASc (P=0.004 for hs-cTnT and P=0.022 hs-cTnI) and 0.61 for ATRIA scores (P=0.005 hs-cTnT and P=0.034 for hs-cTnI)., Conclusions: The biomarker-based ABC-stroke score was well calibrated and consistently performed better than both the CHA 2 DS 2 VASc and ATRIA stroke scores. The ABC score should be considered an improved decision support tool in the care of patients with atrial fibrillation., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifiers: ARISTOTLE, NCT00412984; RE-LY, NCT00262600., (© 2016 American Heart Association, Inc.)

Background: The role of triple antithrombotic therapy vs dual antithrombotic therapy in patients with both atrial fibrillation and coronary artery disease remains unclear. This study explores the differences in treatment practices and outcomes between triple antithrombotic therapy and dual antithrombotic therapy in patients with atrial fibrillation and coronary artery disease., Methods: Using the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (n = 10,135), we analyzed outcomes in patients with coronary artery disease (n = 1827) according to treatment with triple antithrombotic therapy (defined as concurrent therapy with an oral anticoagulant, a thienopyridine, and aspirin) or dual antithrombotic therapy (comprising either an oral anticoagulant and one antiplatelet agent [OAC plus AA] or 2 antiplatelet drugs and no anticoagulant [DAP])., Results: The use of triple antithrombotic therapy, OAC plus AA, and DAP at baseline was 8.5% (n = 155), 80.4% (n = 1468), and 11.2% (n = 204), respectively. Among patients treated with OAC plus AA, aspirin was the most common antiplatelet agent used (90%), followed by clopidogrel (10%) and prasugrel (0.1%). The use of triple antithrombotic therapy was not affected by patient risk of either stroke or bleeding. Patients treated with triple antithrombotic therapy at baseline were hospitalized for all causes (including cardiovascular) more often than patients on OAC plus AA (adjusted hazard ratio 1.75; 95% confidence interval, 1.35-2.26; P <.0001) or DAP (hazard ratio 1.82; 95% confidence interval, 1.25-2.65; P = .0018). Rates of major bleeding or a combined cardiovascular outcome were not significantly different by treatment group., Conclusions: Choice of antithrombotic therapy in patients with atrial fibrillation and coronary artery disease was not affected by patient stroke or bleeding risks. Triple antithrombotic therapy-treated patients were more likely to be hospitalized for all causes than those on OAC plus AA or on DAP., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)

Aims: Atrial fibrillation (AF) is associated with an increased risk of stroke, which is currently estimated by clinical characteristics. The cardiac biomarkers N-terminal fragment B-type natriuretic peptide (NT-proBNP) and cardiac troponin high-sensitivity (cTn-hs) are independently associated with risk of stroke in AF. Our objective was to develop and validate a new biomarker-based risk score to improve prognostication of stroke in patients with AF., Methods and Results: A new risk score was developed and internally validated in 14 701 patients with AF and biomarkers levels determined at baseline, median follow-up of 1.9 years. Biomarkers and clinical variables significantly contributing to predicting stroke or systemic embolism were assessed by Cox-regression and each variable obtained a weight proportional to the model coefficients. External validation was performed in 1400 patients with AF, median follow-up of 3.4 years. The most important predictors were prior stroke/transient ischaemic attack, NT-proBNP, cTn-hs, and age, which were included in the ABC (Age, Biomarkers, Clinical history) stroke risk score. The ABC-stroke score was well calibrated and yielded higher c-indices than the widely used CHA2DS2-VASc score in both the derivation cohort (0.68 vs. 0.62, P < 0.001) and the external validation cohort (0.66 vs. 0.58, P < 0.001). Moreover, the ABC-stroke score consistently provided higher c-indices in several important subgroups., Conclusion: A novel biomarker-based risk score for predicting stroke in AF was successfully developed and internally validated in a large cohort of patients with AF and further externally validated in an independent AF cohort. The ABC-stroke score performed better than the presently used clinically based risk score and may provide improved decision support in AF., Clinicaltrials Gov Identifier: NCT00412984, NCT00799903., (© The Author 2016. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Aims: History of bleeding strongly influences decisions for anticoagulation in atrial fibrillation (AF). We analyzed outcomes in relation to history of bleeding and randomization in ARISTOTLE trial patients., Methods and Results: The on-treatment safety population included 18,140 patients receiving at least 1 dose of study drug (apixaban) or warfarin. Centrally adjudicated outcomes in relation to bleeding history were analyzed using a Cox proportional hazards model adjusted for randomized treatment and established risk factors. Efficacy end points were analyzed on the randomized (intention to treat) population. A bleeding history was reported at baseline in 3,033 patients (16.7%), who more often were male, with a history of prior stroke/transient ischemic attack/systemic embolism and diabetes; higher CHADS2 scores, age, and body weight; and lower creatinine clearance and mean systolic blood pressure. Major (but not intracranial) bleeding occurred more frequently in patients with versus without a history of bleeding (adjusted hazard ratio 1.35, 95% CI 1.14-1.61). There were no significant interactions between bleeding history and treatment for stroke/systemic embolism, hemorrhagic stroke, death, or major bleeding, with fewer outcomes with apixaban versus warfarin for all of these outcomes independent of the presence/absence of a bleeding history., Conclusion: In patients with AF in a randomized clinical trial of oral anticoagulants, a history of bleeding is associated with several risk factors for stroke and portends a higher risk of major-but not intracranial-bleeding, during anticoagulation. However, the beneficial effects of apixaban over warfarin for stroke, hemorrhagic stroke, death, or major bleeding remains consistent regardless of history of bleeding., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)

The North American Thrombosis Forum Atrial Fibrillation Action Initiative consensus document is a comprehensive yet practical briefing document focusing on stroke and bleeding risk assessment in patients with atrial fibrillation, as well as recommendations regarding anticoagulation options and management. Despite the breadth of clinical trial data and guideline recommendation updates, many clinicians continue to struggle to synthesize the disparate information available. This problem slows the uptake and utilization of updated risk prediction tools and adoption of new oral anticoagulants. This document serves as a practical and educational reference for the entire medical community involved in the care of patients with atrial fibrillation., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Patients with atrial fibrillation (AF) and hypertension are at high risk for stroke. Previous studies have shown elevated risk of stroke in patients with AF who have a history of hypertension (regardless of blood pressure [BP] control) and in patients with elevated BP. We assessed the association of hypertension and BP control on clinical outcomes., Methods and Results: In ARISTOTLE (n=18 201), BP was evaluated as history of hypertension requiring treatment and elevated BP (systolic ≥140 and/or diastolic ≥90 mm Hg) at study entry and any point during the trial. Hazard ratios (HRs) were derived from Cox proportional hazards models including BP as a time-dependent covariate. A total of 15 916 (87.5%) patients had a history of hypertension requiring treatment. In patients with elevated BP measurement at any point during the trial, the rate of stroke or systemic embolism was significantly higher (HR, 1.53; 95% confidence interval [CI], 1.25-1.86), as was hemorrhagic stroke (HR 1.85; 95% CI, 1.26-2.72) and ischemic stroke (HR, 1.50; 95% CI, 1.18-1.90). Rates of major bleeding were lower in patients with a history of hypertension (HR, 0.80; 95% CI, 0.66-0.98) and nonsignificantly lower in patients with elevated BP at study entry (HR, 0.89; 95% CI, 0.77-1.03). The benefit of apixaban versus warfarin on preventing stroke or systemic embolism was consistent among patients with and without a history of hypertension (P interaction=0.27), BP control at baseline (P interaction=0.43), and BP control during the trial (P interaction=0.97)., Conclusions: High BP measurement at any point during the trial was independently associated with a substantially higher risk of stroke or systemic embolism. These results strongly support efforts to treat elevated BP as an important strategy to optimally lower risk of stroke in patients with AF., Clinical Trial Registration: URL: https://ClinicalTrials.gov/. Unique identifier: NCT00412984., (© 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.)

Among patients receiving oral anticoagulation for atrial fibrillation (AF), heart failure (HF) is associated with poor anticoagulation control. However, it is not known which patients with heart failure are at greatest risk of adverse outcomes. We evaluated 62,156 Veterans Health Administration (VA) patients receiving warfarin for AF between 10/1/06-9/30/08 using merged VA-Medicare dataset. We predicted time in therapeutic range (TTR) and rates of adverse events by categorising patients into those with 0, 1, 2, or 3+ of five putative markers of HF severity such as aspartate aminotransferase (AST)> 80 U/l, alkaline phosphatase> 150 U/l, serum sodium< 130 mEq/l, any receipt of metolazone, and any inpatient admission for HF exacerbation. These risk categories predicted TTR: patients without HF (referent) had a mean TTR of 65.0 %, while HF patients with 0, 1, 2, 3 or more markers had mean TTRs of 62.2 %, 57.2 %, 53.5 %, and 50.7 %, respectively (p< 0.001). These categories also discriminated for major haemorrhage well; compared to patients without HF, HF patients with increasing severity had hazard ratios of 1.84, 3.06, 3.52 and 5.14 respectively (p< 0.001). However, although patients with HF had an elevated hazard for bleeding compared to those without HF, these categories did not effectively discriminate risk of ischaemic stroke across HF. In conclusion, we developed a HF severity model using easily available clinical characteristics that performed well to risk-stratify patients with HF who are receiving anticoagulation for AF with regard to major haemorrhage.

Background: Time in therapeutic range (TTR) of international normalized ratio (INR) of 2.0 to 3.0 is important for the safety and effectiveness of warfarin anticoagulation. There are few data on TTR among patients with atrial fibrillation (AF) in community-based clinical practice., Methods: Using the US Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF), we examined TTR (using a modified Rosendaal method) among 5,210 patients with AF on warfarin and treated at 155 sites. Patients were grouped into quartiles based on TTR data. Multivariable logistic regression modeling with generalized estimating equations was used to determine patient and provider factors associated with the lowest (worst) TTR., Results: Overall, 59% of the measured INR values were between 2.0 and 3.0, with an overall mean and median TTR of 65% ± 20% and 68% (interquartile range [IQR] 53%-79%). The median times below and above the therapeutic range were 17% (IQR 8%-29%) and 10% (IQR 3%-19%), respectively. Patients with renal dysfunction, advanced heart failure, frailty, prior valve surgery, and higher risk for bleeding (ATRIA score) or stroke (CHA2DS2-VASc score) had significantly lower TTR (P < .0001 for all). Patients treated at anticoagulation clinics had only slightly higher median TTR (69%) than those not (66%) (P < .0001)., Conclusions: Among patients with AF in US clinical practices, TTR on warfarin is suboptimal, and those at highest predicted risks for stroke and bleeding were least likely to be in therapeutic range., (Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.)

Aim: In the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial, apixaban compared with warfarin reduced the risk of stroke, major bleed, and death in patients with atrial fibrillation. In this ancillary study, we evaluated clinical consequences of major bleeds, as well as management and treatment effects of warfarin vs. apixaban., Methods and Results: Major International Society on Thrombosis and Haemostasis bleeding was defined as overt bleeding accompanied by a decrease in haemoglobin (Hb) of ≥2 g/dL or transfusion of ≥2 units of packed red cells, occurring at a critical site or resulting in death. Time to event [death, ischaemic stroke, or myocardial infarction (MI)] was evaluated by Cox regression models. The excess risk associated with bleeding was evaluated by separate time-dependent indicators for intracranial (ICH) and non-intracranial haemorrhage. Major bleeding occurred in 848 individuals (4.7%), of whom 126 (14.9%) died within 30 days. Of 176 patients with an ICH, 76 (43.2%) died, and of the 695 patients with major non-ICH, 64 (9.2%) died within 30 days of the bleeding. The risk of death, ischaemic stroke, or MI was increased roughly 12-fold after a major non-ICH bleeding event within 30 days. Corresponding risk of death following an ICH was markedly increased, with HR 121.5 (95% CI 91.3-161.8) as was stroke or MI with HR 21.95 (95% CI 9.88-48.81), respectively. Among patients with major bleeds, 20.8% received vitamin K and/or related medications (fresh frozen plasma, coagulation factors, factor VIIa) to stop bleeding within 3 days, and 37% received blood transfusion. There was no interaction between apixaban and warfarin and major bleeding on the risk of death, stroke, or MI., Conclusion: Major bleeding was associated with substantially increased risk of death, ischaemic stroke, or MI, especially following ICH, and this risk was similarly elevated regardless of treatment with apixaban or warfarin. These results underscore the importance of preventing bleeding in anti-coagulated patients. ClinicalTrials.gov Identifier: NCT00412984., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.)

Objective: Given conflicting data regarding the association of HIV infection and ischemic stroke risk, we sought to determine whether HIV infection conferred an increased ischemic stroke risk among male veterans., Methods: The Veterans Aging Cohort Study-Virtual Cohort consists of HIV-infected and uninfected veterans in care matched (1:2) for age, sex, race/ethnicity, and clinical site. We analyzed data on 76,835 male participants in the Veterans Aging Cohort Study-Virtual Cohort who were free of baseline cardiovascular disease. We assessed demographics, ischemic stroke risk factors, comorbid diseases, substance use, HIV biomarkers, and incidence of ischemic stroke from October 1, 2003, to December 31, 2009., Results: During a median follow-up period of 5.9 (interquartile range 3.5-6.6) years, there were 910 stroke events (37.4% HIV-infected). Ischemic stroke rates per 1,000 person-years were higher for HIV-infected (2.79, 95% confidence interval 2.51-3.10) than for uninfected veterans (2.24 [2.06-2.43]) (incidence rate ratio 1.25 [1.09-1.43]; p < 0.01). After adjusting for demographics, ischemic stroke risk factors, comorbid diseases, and substance use, the risk of ischemic stroke was higher among male veterans with HIV infection compared with uninfected veterans (hazard ratio 1.17 [1.01-1.36]; p = 0.04)., Conclusions: HIV infection is associated with an increased ischemic stroke risk among HIV-infected compared with demographically and behaviorally similar uninfected male veterans., (© 2015 American Academy of Neurology.)

Background: Although cardiac troponin is associated with outcomes in atrial fibrillation (AF), the complementary prognostic information provided by cardiac troponin I (cTnI) and cTnT is unknown. This study investigated the distribution, determinants, and prognostic value of cTnI and cTnT concentrations in patients with AF., Methods: Samples were collected. At the time of randomization, we analyzed cTnI and cTnT concentrations of 14806 AF patients in the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial using high-sensitivity assays. Correlations (Spearman), determinants (multivariable linear regression), and outcomes (adjusted Cox models and c-statistics) were investigated., Results: Concentrations of cTnI and cTnT were correlated (r = 0.70) and measurable in most participants [cTnI 98.5% (median 5.4 ng/L, ≥99th percentile in 9.2%) and cTnT 93.5% (median 10.9 ng/L, ≥99th percentile in 34.4%)]. Renal impairment was the most important factor affecting the concentrations of both troponins. cTnI increase was more associated with heart failure, vascular disease, and persistent/permanent AF, and cTnT with age, male sex, and diabetes. Over a median 1.9 years of follow-up, patients with both troponins above the median had significantly higher risk for stroke/systemic embolism [hazard ratio (HR) 1.72 (95% CI 1.31-2.27)], cardiac death [3.14 (2.35-4.20)], and myocardial infarction [2.99 (1.78-5.03)] than those with both troponins below median (all P < 0.005). Intermediate risks were observed when only 1 troponin was above the median. When combined with clinical information, each marker provided similar prognostication and had comparable c-index., Conclusions: cTnI and cTnT concentrations are moderately correlated and measurable in plasma of most AF patients. The risk of stroke and cardiovascular events is highest when both troponins are above median concentrations. Each troponin provides comparable prognostic information when combined with clinical risk factors. ClinicalTrials.gov/NCT00412984., (© 2014 American Association for Clinical Chemistry.)

Background: Because of its association with death and disability, stroke is a focus of outcomes in atrial fibrillation (AF) research. International Classification of Disease-Ninth Revision (ICD-9) edition codes are commonly used to identify stroke in research, particularly in large administrative data. We sought to assess the validity of ICD-9 codes in stroke case ascertainment and for AF across 3 institutions., Methods and Results: Participating centers included Boston Medical Center (safety net hospital), Geisinger Health System (rural Pennsylvania), and the University of Alabama (academic center in the southeastern stroke belt). ICD-9 codes for ischemic stroke (433-434, 436) and intracranial hemorrhage (430-432) identified 1812 stroke cases with an associated code for AF (427.31) from 2006 to 2010. Cases were vetted through chart review with final adjudication by a stroke neurologist. Review considered 94.2% of ICD-9 identified stroke cases valid with decreased accuracy for concurrent AF diagnosis (82.28%) and stroke attributable to AF (72.8%). Among events with "without infarction" modifiers, 7.2% were valid strokes. ICD-9 stroke code accuracy did not differ by stroke type or site. Stroke code 434 displayed higher accuracy than 433 (94.4% versus 85.2%; P<0.01), and primary stroke codes were more accurate than nonprimary codes (97.2% versus 83.7%; P<0.0001)., Conclusions: Using ICD-9 stroke and AF codes to identify patients with stroke plus AF resulted in inaccuracies. Given the expanded financial and policy implications of patient-oriented research, conclusions derived solely from administrative data without validation of outcome events should be interpreted with caution., (© 2015 American Heart Association, Inc.)

Lone atrial fibrillation (LAF) is generally regarded as a benign disorder that does not significantly increase the risk of thromboembolism and mortality. However, there is growing evidence that "lone" atrial fibrillation (AF) is a "heterogeneous" disorder with varying risk for thromboembolism based on the patient's underlying cardiovascular risk factors. Blood biomarkers, including markers of myocardial strain, inflammation, endothelial injury, platelet activation, and hypercoagulability, have potential to improve our risk stratification and management of LAF. Currently, there is a paucity of data on biomarkers in strictly defined LAF. The majority of studies that aimed to study lone atrial fibrillation excluded patients with structural heart disease, but did not exclude patients with co-existing cardiovascular risk factors such as hypertension or diabetes mellitus. Moreover, many of the studies did not exclude patients based on age, thereby increasing the likelihood of including patients with cardiovascular co-morbidities. There are currently a limited number of studies aimed to investigate the role of biomarkers in true LAF. The results are conflicting as to whether these biomarkers are associated with LAF or stroke risk. Future studies enrolling patients with true LAF using strict definition are needed. Herein, we review our current knowledge of biomarkers in association with atrial fibrillation and LAF and discuss their potential clinical utility.

Using data from ARISTOTLE, we describe the periprocedural management of anticoagulation and rates of subsequent clinical outcomes among patients chronically anticoagulated with warfarin or apixaban. We recorded whether (and for how long) anticoagulant therapy was interrupted preprocedure, whether bridging therapy was used, and the proportion of patients who experienced important clinical outcomes during the 30 days postprocedure. Of 10 674 procedures performed during follow-up in 5924 patients, 9260 were included in this analysis. Anticoagulant treatment was not interrupted preprocedure 37.5% of the time. During the 30 days postprocedure, stroke or systemic embolism occurred after 16/4624 (0.35%) procedures among apixaban-treated patients and 26/4530 (0.57%) procedures among warfarin-treated patients (odds ratio [OR] 0.601; 95% confidence interval [CI] 0.322-1.120). Major bleeding occurred in 74/4560 (1.62%) procedures in the apixaban arm and 86/4454 (1.93%) in the warfarin arm (OR 0.846; 95% CI 0.614-1.166). The risk of death was similar with apixaban (54/4624 [1.17%]) and warfarin (49/4530 [1.08%]) (OR 1.082; 95% CI 0.733-1.598). Among patients in ARISTOTLE, the 30-day postprocedure stroke, death, and major bleeding rates were low and similar in apixaban- and warfarin-treated patients, regardless of whether anticoagulation was stopped beforehand. Our findings suggest that many patients on chronic anticoagulation can safely undergo procedures; some will not require a preprocedure interruption of anticoagulation. ARISTOTLE was registered at www.clinicaltrials.gov as #NCT00412984., (© 2014 by The American Society of Hematology.)

Background: Growth differentiation factor 15 (GDF-15), high-sensitivity troponin, and N-terminal pro-brain natriuretic peptide levels are predictive of death and cardiovascular events in healthy elderly subjects, patients with acute coronary syndrome, and patients with heart failure. High-sensitivity troponin I and N-terminal pro-brain natriuretic peptide are also prognostic in patients with atrial fibrillation. We evaluated the prognostic value of GDF-15 alone and in addition to clinical characteristics and other biomarkers in patients with atrial fibrillation., Methods and Results: The Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial randomized 18 201 patients with atrial fibrillation to apixaban or warfarin. Biomarkers were measured at randomization in 14 798 patients. Efficacy and safety outcomes during 1.9 years of follow-up were compared across quartiles of GDF-15 by use of Cox analyses adjusted for clinical characteristics, randomized treatment, and other biomarkers. The GDF-15 level showed a median of 1383 ng/L (interquartile range, 977-2052 ng/L). Annual rates of stroke or systemic embolism ranged from 0.9% to 2.03% (P<0.001); of major bleeding, from 1.22% to 4.53% (P<0.001); and of mortality, from 1.34% to 7.19% (P<0.001) in the lowest compared with the highest GDF-15 quartile. The prognostic information provided by GDF-15 was independent of clinical characteristics and clinical risk scores. Adjustment for the other cardiac biomarkers attenuated the prognostic value for stroke, whereas the prognostic value for mortality and major bleeding remained. Apixaban consistently reduced stroke, mortality, and bleeding, regardless of GDF-15 levels., Conclusions: GDF-15 is a risk factor for major bleeding, mortality, and stroke in atrial fibrillation. The prognostic value for major bleeding and death remained even in the presence of N-terminal pro-brain natriuretic peptide and high-sensitivity troponin I., Clinical Trial Registration Url: http://www.clinicaltrials.gov. Unique identifier: NCT00412984., (© 2014 American Heart Association, Inc.)

Aims: The risk of stroke in patients with atrial fibrillation (AF) increases with age. In the ARISTOTLE trial, apixaban when compared with warfarin reduced the rate of stroke, death, and bleeding. We evaluated these outcomes in relation to patient age., Methods and Results: A total of 18 201 patients with AF and a raised risk of stroke were randomized to warfarin or apixaban 5 mg b.d. with dose reduction to 2.5 mg b.d. or placebo in 831 patients with ≥2 of the following criteria: age ≥80 years, body weight ≤60 kg, or creatinine ≥133 μmol/L. We used Cox models to compare outcomes in relation to patient age during 1.8 years median follow-up. Of the trial population, 30% were <65 years, 39% were 65 to <75, and 31% were ≥75 years. The rates of stroke, all-cause death, and major bleeding were higher in the older age groups (P < 0.001 for all). Apixaban was more effective than warfarin in preventing stroke and reducing mortality across all age groups, and associated with less major bleeding, less total bleeding, and less intracranial haemorrhage regardless of age (P interaction >0.11 for all). Results were also consistent for the 13% of patients ≥80 years. No significant interaction with apixaban dose was found with respect to treatment effect on major outcomes., Conclusion: The benefits of apixaban vs. warfarin were consistent in patients with AF regardless of age. Owing to the higher risk at older age, the absolute benefits of apixaban were greater in the elderly., (© The Author 2014. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Objectives: This study sought to characterize major bleeding on the basis of the components of the major bleeding definition, to explore major bleeding by location, to define 30-day mortality after a major bleeding event, and to identify factors associated with major bleeding., Background: Apixaban was shown to reduce the risk of major hemorrhage among patients with atrial fibrillation in the ARISTOTLE (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation) trial., Methods: All patients who received at least 1 dose of a study drug were included. Major bleeding was defined according to the criteria of the International Society on Thrombosis and Haemostasis. Factors associated with major hemorrhage were identified using a multivariable Cox model., Results: The on-treatment safety population included 18,140 patients. The rate of major hemorrhage among patients in the apixaban group was 2.13% per year compared with 3.09% per year in the warfarin group (hazard ratio [HR] 0.69, 95% confidence interval [CI]: 0.60 to 0.80; p < 0.001). Compared with warfarin, major extracranial hemorrhage associated with apixaban led to reduced hospitalization, medical or surgical intervention, transfusion, or change in antithrombotic therapy. Major hemorrhage followed by mortality within 30 days occurred half as often in apixaban-treated patients than in those receiving warfarin (HR 0.50, 95% CI: 0.33 to 0.74; p < 0.001). Older age, prior hemorrhage, prior stroke or transient ischemic attack, diabetes, lower creatinine clearance, decreased hematocrit, aspirin therapy, and nonsteroidal anti-inflammatory drugs were independently associated with an increased risk., Conclusions: Apixaban, compared with warfarin, was associated with fewer intracranial hemorrhages, less adverse consequences following extracranial hemorrhage, and a 50% reduction in fatal consequences at 30 days in cases of major hemorrhage., (Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Physicians treating patients with atrial fibrillation (AF) must weigh the benefits of anticoagulation in preventing stroke versus the risk of bleeding. Although empirical models have been developed to predict such risks, the degree to which these coincide with clinicians' estimates is unclear., Methods and Results: We examined 10 094 AF patients enrolled in the Outcomes Registry for Better Informed Treatment of AF (ORBIT-AF) registry between June 2010 and August 2011. Empirical stroke and bleeding risks were assessed by using the congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, and previous stroke or transient ischemic attack (CHADS2) and Anticoagulation and Risk Factors in Atrial Fibrillation (ATRIA) scores, respectively. Separately, physicians were asked to categorize their patients' stroke and bleeding risks: low risk (<3%); intermediate risk (3%-6%); and high risk (>6%). Overall, 72% (n=7251) in ORBIT-AF had high-risk CHADS2 scores (≥2). However, only 16% were assessed as high stroke risk by physicians. Although 17% (n=1749) had high ATRIA bleeding risk (score ≥5), only 7% (n=719) were considered so by physicians. The associations between empirical and physician-estimated stroke and bleeding risks were low (weighted Kappa 0.1 and 0.11, respectively). Physicians weighed hypertension, heart failure, and diabetes mellitus less significantly than empirical models in estimating stroke risk; physicians weighted anemia and dialysis less significantly than empirical models when estimating bleeding risks. Anticoagulation use was highest among patients with high stroke risk, assessed by either empirical model or physician estimates. In contrast, physician and empirical estimates of bleeding had limited impact on treatment choice., Conclusions: There is little agreement between provider-assessed risk and empirical scores in AF. These differences may explain, in part, the current divergence of anticoagulation treatment decisions from guideline recommendations., Clinical Trial Registration Url: http://www.clinicaltrials.gov. Unique identifier: NCT01165710., (© 2014 American Heart Association, Inc.)

Worldwide there is a tremendous need for affordable anticoagulants that do not require monitoring. The advent of the non-warfarin oral anticoagulant drugs represents a major advance for stroke prevention in atrial fibrillation (AF). The objectives of this review are to 1) identify gaps in our current knowledge regarding use of these single target anticoagulant drugs; 2) outline the potential implications of these gaps for clinical practice, and thereby, 3) highlight areas of research to further optimise their use for stroke prevention in AF.

Background: Anticoagulation control with warfarin, as assessed by the international normalized ratio (INR), is challenging. Time in the therapeutic range has been inversely correlated with major hemorrhage, thrombosis, and mortality. Quest Diagnostics offers standardized INR laboratory testing services to approximately half of US physician practices. To inform national stroke prevention strategies, we evaluated anticoagulation control in office-based community practices., Methods and Results: We selected individuals with ≥2 months of INR data, INR results of >1.2, and an ICD-9 diagnosis code of atrial fibrillation. Frequency of INR testing and time in the therapeutic range were analyzed by age, sex, length of testing period, number of referred patients per provider, and median household income (based on home ZIP code). We identified 138 319 individuals referred by 37 939 physicians, yielding a total of 2 683 674 INR results. Patients had a mean age of 74 years; 81% were ≥65 years of age, and 55% were ≥75 years of age. The mean time in the therapeutic range was 53.7% overall and improved with time on treatment, increasing from 47.6% for patients with <6 months of testing to 57.5% for those with ≥6 months of testing (P<0.0001). The number of patients tested per physician practice was positively associated with time in the therapeutic range. Younger age, female sex, and lower income were also independently associated with poorer anticoagulant control., Conclusion: This study demonstrates widespread suboptimal anticoagulation control, suggesting an urgent need to improve oral anticoagulation care for most patient segments in the United States.

Background: High-sensitivity troponin-I (hs-TnI) measurement improves risk assessment for cardiovascular events in many clinical settings, but the added value in atrial fibrillation patients has not been described., Methods and Results: At randomization, hs-TnI was analyzed in 14 821 atrial fibrillation patients in the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial comparing apixaban with warfarin. The associations between hs-TnI concentrations and clinical outcomes were evaluated by using adjusted Cox analysis. The hs-TnI assay detected troponin (≥1.3 ng/L) in 98.5% patients, 50% had levels >5.4, 25% had levels >10.1, and 9.2% had levels ≥23 ng/L (the 99th percentile in healthy individuals). During a median of 1.9 years follow-up, annual rates of stroke or systemic embolism ranged from 0.76% in the lowest hs-TnI quartile to 2.26% in the highest quartile (>10.1 ng/L). In multivariable analysis, hs-TnI was significantly associated with stroke or systemic embolism, adjusted hazard ratio 1.98 (1.42-2.78), P=0.0007. hs-TnI was also significantly associated with cardiac death; annual rates ranged from 0.40% to 4.24%, hazard ratio 4.52 (3.05-6.70), P<0.0001, in the corresponding groups, and for major bleeding hazard ratio 1.44 (1.11-1.86), P=0.0250. Adding hs-TnI levels to the CHA2DS2VASc score improved c-statistics from 0.629 to 0.653 for stroke or systemic embolism, and from 0.591 to 0.731 for cardiac death. There were no significant interactions with study treatment., Conclusions: Troponin-I is detected in 98.5% and elevated in 9.2% of atrial fibrillation patients. The hs-TnI level is independently associated with a raised risk of stroke, cardiac death, and major bleeding and improves risk stratification beyond the CHA2DS2VASc score. The benefits of apixaban in comparison with warfarin are consistent regardless of hs-TnI levels., Clinical Trial Registration Url: http://www.clinicaltrials.gov. Unique identifier: NCT00412984.