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Background We sought to determine recurrent stroke predictors among patients with embolic strokes of undetermined source (ESUS). Methods and Results We applied Cox proportional hazards models to identify clinical features associated with recurrent stroke among participants enrolled in RE-SPECT ESUS (Randomized, Double-Blind, Evaluation in Secondary Stroke Prevention Comparing the Efficacy and Safety of the Oral Thrombin Inhibitor Dabigatran Etexilate Versus Acetylsalicylic Acid in Patients With Embolic Stroke of Undetermined Source) trial, an international clinical trial evaluating dabigatran versus aspirin for patients with ESUS. During a median follow-up of 19 months, 384 of 5390 participants had recurrent stroke (annual rate, 4.5%). Multivariable models revealed that stroke or transient ischemic attack before the index event (hazard ratio [HR], 2.27 [95% CI, 1.83-2.82]), creatinine clearance <50 mL/min (HR, 1.69 [95% CI, 1.23-2.32]), male sex (HR, 1.60 [95% CI, 1.27-2.02]), and CHA 2 DS 2 -VASc ≥4 (HR, 1.55 [95% CI, 1.15-2.08] and HR, 1.66 [95% CI, 1.21-2.26] for scores of 4 and ≥5, respectively) versus CHA 2 DS 2 -VASc of 2 to 3, were independent predictors for recurrent stroke. Conclusions In RE-SPECT ESUS trial, expected risk factors previously linked to other common stroke causes were associated with stroke recurrence. These data help define high-risk groups for subsequent stroke that may be useful for clinicians and for researchers designing trials among patients with ESUS. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02239120.

Prevalence of atrial fibrillation (AF) increases with age, along with comorbidities and, thus, polypharmacy. Non-adherence is associated with polypharmacy. This study aimed to identify patients at risk for cardiovascular events according to their pharmacological treatment intensity and adherence. Patients (n = 18,113) with a mean age of 71.5 ± 8.7 years, at high cardiovascular risk were followed between December 2005 until December 2007 for a median time of 2 years. The association between polypharmacy and adherence and their impact on cardiovascular and bleeding events were explored. Adherence was defined as a study drug intake of ≥80%. Patients with more co-medications had a higher body mass index, higher prevalence of hypertension, coronary heart disease, heart failure, and diabetes mellitus (all p < 0.0001) compared to ≤4 or 5-8 co-medications, but no differences in history of stroke (p = 0.68) or transient ischemic attack (p = 0.065). Across all treatments, the adjusted hazard ratios (HRs) increased in patients with more co-medications (≥9 vs ≤4) for all-cause death (HR 1.30; 1.06-1.59), major bleeding (HR 1.65; 1.33-2.05), and all bleeding events (HR 1.44; 1.31-1.59). Yearly event rates were higher in non-adherent than adherent patients for stroke and systemic embolism (SSE) (3.14 vs 1.00), all-cause death (7.76 vs 2.66), major bleeding (6.21 vs 2.65), and all bleeding (28.71 vs 19.05; all p < 0.0001). After an event the patients were more likely to become non-adherent (adherence after SSE 30.3%, after major bleeding 33.4%, after all bleeding 66.7%; all p < 0.0001). The treatment effects were consistent to the overall group in the different polypharmacy groups. In conclusion, polypharmacy and non-adherence are risk indicators for increased adverse cardiovascular and bleeding events. Dabigatran is safe to use across the full spectrum of AF patients, independent of the number of co-medications and adherence. Patients with co-medications and comorbidities require special attention and encouragement to adhere to oral anticoagulation., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Aims: A J-shaped association of cardiovascular events to achieved systolic (SBP) and diastolic (DBP) blood pressure was shown in high-risk patients. This association on oral anticoagulation is unknown. This analysis from RELY assessed the risks of death, stroke or systemic emboli, and bleeding according to mean achieved SBP and DBP in atrial fibrillation on oral anticoagulation., Methods and Results: RE-LY patients were followed for 2 years and recruited between 22 December 2005 until 15 December 2007. 18.113 patients were randomized in 951 centres in 54 countries and 18,107 patients with complete blood pressure (BP) data were analysed with a median follow-up of 2.0 years and a complete follow-up in 99.9%. The association between achieved mean SBP and DBP on all-cause death, stroke and systemic embolic events (SSE), major, and any bleeding were explored. On treatment, SBP >140 mmHg and <120 mmHg was associated with all-cause death compared with SBP 120-130 mmHg (reference). For SSE, risk was unchanged at SBP <110 mmHg but increased at 140-160 mmHg (adjusted hazard ratio (HR) 1.81; 1.40-2.33) and SBP ≥160 mmHg (HR 3.35; 2.09-5.36). Major bleeding events were also increased at <110 mmHg and at 110 to <120 mmHg. Interestingly, there was no increased risk of major bleeding at SBP >130 mmHg. Similar patterns were observed for DBP with an increased risk at <70 mmHg (HR 1.55; 1.35-1.78) and >90 mmHg (HR 1.88; 1.43-2.46) for all-cause death compared to 70 to <80 mmHg (reference). Risk for any bleeding was increased at low DBP <70 mmHg (HR 1.46; 1.37-1.56) at DBP 80 to <90 mmHg (HR 1.13; 1.06-1.31) without increased risk at higher achieved DBP. Dabigatran 150 mg twice daily showed an advantage in all patients for all-cause death and SSE and there was an advantage for 110 mg dabigatran twice daily for major bleeding and any bleeding irrespective of SBP or DBP achieved. Similar results were obtained for baseline BP, time-updated BP, and BP as time-varying covariate., Conclusion: Low achieved SBP associates with increased risk of death, SSE, and bleeding in patients with atrial fibrillation on oral anticoagulation. Major bleeding events did not occur at higher BP. Low BP might identify high-risk patients not only for death but also for high bleeding risks., Clinical Trial Registration: ClinicalTrials.gov-Identifier: NCT00262600., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

Background and Purpose- The RE-SPECT ESUS trial (Randomized, Double-Blind, Evaluation in Secondary Stroke Prevention Comparing the Efficacy and Safety of the Oral Thrombin Inhibitor Dabigatran Etexilate Versus Acetylsalicylic Acid in Patients With Embolic Stroke of Undetermined Source) tested the hypothesis that dabigatran would be superior to aspirin for the prevention of recurrent stroke in patients with embolic stroke of undetermined source. This exploratory subgroup analysis investigates the impact of age, renal function (both predefined), and dabigatran dose (post hoc) on the rates of recurrent stroke and major bleeding. Methods- RE-SPECT ESUS was a multicenter, randomized, double-blind trial of dabigatran 150 or 110 mg (for patients aged ≥75 years and/or with creatinine clearance 30 to <50 mL/minute) twice daily compared with aspirin 100 mg once daily. The primary outcome was recurrent stroke. Results- The trial, which enrolled 5390 patients from December 2014 to January 2018, did not demonstrate superiority of dabigatran versus aspirin for prevention of recurrent stroke in patients with embolic stroke of undetermined source. However, among the population qualifying for the lower dabigatran dose, the rate of recurrent stroke was reduced with dabigatran versus aspirin (7.4% versus 13.0%; hazard ratio, 0.57 [95% CI, 0.39-0.82]; interaction P =0.01). This was driven mainly by the subgroup aged ≥75 years (7.8% versus 12.4%; hazard ratio, 0.63 [95% CI, 0.43-0.94]; interaction P =0.10). Stroke rates tended to be lower with dabigatran versus aspirin with declining renal function. Risks for major bleeding were similar between treatments, irrespective of renal function, but with a trend for lower bleeding rates with dabigatran versus aspirin in older patients. Conclusions- In subgroup analyses of RE-SPECT ESUS, dabigatran reduced the rate of recurrent stroke compared with aspirin in patients qualifying for the lower dose of dabigatran. These results are hypothesis-generating. Aspirin remains the standard antithrombotic treatment for patients with embolic stroke of undetermined source. Registration- URL: https://www.clinicaltrials.gov; Unique identifier: NCT02239120.

Background: In the RE-DUAL PCI trial of patients with atrial fibrillation (AF) who underwent percutaneous coronary intervention (PCI), dabigatran dual therapy (110 or 150 mg bid, plus clopidogrel or ticagrelor) reduced International Society on Thrombosis and Haemostasis bleeding events compared with warfarin triple therapy, with noninferiority in overall thromboembolic events. This analysis assessed outcomes in relation to patient bleeding and stroke risk profiles, based on the modified HAS-BLED and CHA 2 DS 2 -VASc scores., Methods: The primary endpoint, major bleeding event (MBE) or clinically relevant nonmajor bleeding event (CRNMBE), was compared across study arms in patients categorized by modified HAS-BLED score 0-2 or ≥3. The composite endpoint of death, thromboembolic event, and unplanned revascularization rates was compared in patients categorized by CHA 2 DS 2 -VASc score 0-1, 2, or ≥3., Results: Risk of MBE or CRNMBE was lower with dabigatran dual therapy (both doses) versus warfarin triple therapy, irrespective of modified HAS-BLED category (treatment-by-subgroup interaction P-value 0.584 and 0.273 for dabigatran 110 and 150 mg dual therapy, respectively, vs warfarin). Risk of the composite thromboembolic endpoint was similar across CHA 2 DS 2 -VASc categories and consistent with overall study results (interaction P-value 0.739 and 0.075 for dabigatran 110 and 150 mg dual therapy, respectively, vs warfarin). Higher HAS-BLED scores were associated with higher risks of bleeding in AF patients after PCI in a treatment-independent analysis., Conclusion: Dabigatran dual therapy reduced bleeding events irrespective of bleeding risk category and demonstrated similar efficacy regardless of stroke risk category when compared with warfarin triple therapy., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Cryptogenic strokes constitute 20 to 30% of ischemic strokes, and most cryptogenic strokes are considered to be embolic and of undetermined source. An earlier randomized trial showed that rivaroxaban is no more effective than aspirin in preventing recurrent stroke after a presumed embolic stroke from an undetermined source. Whether dabigatran would be effective in preventing recurrent strokes after this type of stroke was unclear., Methods: We conducted a multicenter, randomized, double-blind trial of dabigatran at a dose of 150 mg or 110 mg twice daily as compared with aspirin at a dose of 100 mg once daily in patients who had had an embolic stroke of undetermined source. The primary outcome was recurrent stroke. The primary safety outcome was major bleeding., Results: A total of 5390 patients were enrolled at 564 sites and were randomly assigned to receive dabigatran (2695 patients) or aspirin (2695 patients). During a median follow-up of 19 months, recurrent strokes occurred in 177 patients (6.6%) in the dabigatran group (4.1% per year) and in 207 patients (7.7%) in the aspirin group (4.8% per year) (hazard ratio, 0.85; 95% confidence interval [CI], 0.69 to 1.03; P = 0.10). Ischemic strokes occurred in 172 patients (4.0% per year) and 203 patients (4.7% per year), respectively (hazard ratio, 0.84; 95% CI, 0.68 to 1.03). Major bleeding occurred in 77 patients (1.7% per year) in the dabigatran group and in 64 patients (1.4% per year) in the aspirin group (hazard ratio, 1.19; 95% CI, 0.85 to 1.66). Clinically relevant nonmajor bleeding occurred in 70 patients (1.6% per year) and 41 patients (0.9% per year), respectively., Conclusions: In patients with a recent history of embolic stroke of undetermined source, dabigatran was not superior to aspirin in preventing recurrent stroke. The incidence of major bleeding was not greater in the dabigatran group than in the aspirin group, but there were more clinically relevant nonmajor bleeding events in the dabigatran group. (Funded by Boehringer Ingelheim; RE-SPECT ESUS ClinicalTrials.gov number, NCT02239120.)., (Copyright © 2019 Massachusetts Medical Society.)

Background: Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used medications that can potentially increase the risk of bleeding and thrombosis., Objectives: This study quantified the effect of NSAIDs in the RE-LY (Randomized Evaluation of Long Term Anticoagulant Therapy) trial., Methods: This was a post hoc analysis of NSAIDs in the RE-LY study, which compared dabigatran etexilate (DE) 150 and 110 mg twice daily (b.i.d.) with warfarin in patients with atrial fibrillation. Treatment-independent, multivariate-adjusted Cox regression analysis assessed clinical outcomes by comparing NSAID use with no NSAID use. Interaction analysis was obtained from treatment-dependent Cox regression modeling. Time-varying covariate analysis for NSAID use was applied to the Cox model., Results: Among 18,113 patients in the RE-LY study, 2,279 patients used NSAIDs at least once during the trial. Major bleeding was significantly elevated with NSAID use (hazard ratio [HR]: 1.68; 95% confidence interval [CI]: 1.40 to 2.02; p < 0.0001). NSAID use did not significantly alter the risk of major bleeding for DE 150 or 110 mg b.i.d. relative to warfarin (p interaction  = 0.63 and 0.93, respectively). Gastrointestinal major bleeding was significantly elevated with NSAID use (HR: 1.81; 95% CI: 1.35 to 2.43; p < 0.0001). The rate of stroke or systemic embolism (stroke/SE) with NSAID use was significantly elevated (HR: 1.50; 95% CI: 1.12 to 2.01; p = 0.007). The use of NSAIDs did not significantly alter the relative efficacy on stroke/SE for DE 150 or 110 mg b.i.d. relative to warfarin (p interaction  = 0.59 and 0.54, respectively). Myocardial infarction rates were similar with NSAID use compared with no NSAID use (HR: 1.22; 95% CI: 0.77 to 1.93; p = 0.40). Patients were more frequently hospitalized if they used an NSAID (HR: 1.64; 95% CI: 1.51 to 1.77; p < 0.0001)., Conclusions: The use of NSAIDs was associated with increased risk of major bleeding, stroke/SE, and hospitalization. The safety and efficacy of DE 150 and 110 mg b.i.d. relative to warfarin were not altered. (Randomized Evaluation of Long Term Anticoagulant Therapy [RE-LY]; NCT00262600)., (Copyright © 2018. Published by Elsevier Inc.)

Background: Current guidelines recommend non-vitamin K antagonist oral anticoagulants (NOACs) as the first-choice therapy in patients with nonvalvular atrial fibrillation because these drugs have several benefits over the vitamin K antagonists (VKAs). It is unknown whether these benefits remain when NOACs have to be combined with aspirin therapy. To assess the efficacy and safety of NOACs compared with VKAs in patients with atrial fibrillation and concomitant aspirin therapy, we conducted a systematic review and study-based meta-analysis of published randomized controlled trials., Methods: A systematic electronic literature search was done in MEDLINE, EMBASE, and Cochrane CENTRAL Register of Controlled Trials for studies including published data of patients ≥18 years of age with nonvalvular atrial fibrillation, randomized to either VKAs or NOACs, or receiving aspirin therapy at any time during the study that report all-cause stroke or systemic embolism, vascular death, myocardial infarction, major bleeding, or intracranial hemorrhage as an outcome. Hazard ratios (HRs) with 95% confidence intervals (CIs) for each outcome were extracted from the individual studies and pooled with random-effects meta-analysis., Results: This study-based meta-analysis was restricted to the subgroups of patients on aspirin therapy (n=21 722) from 4 randomized controlled trials comparing VKAs and NOACs (n=71 681) in nonvalvular atrial fibrillation. In this meta-analysis including patients on mainly low-dose aspirin, NOACs were found to be more effective (outcome of stroke or systemic embolism: HR, 0.78; 95% CI, 0.67-0.91; vascular death: HR, 0.85; 95% CI, 0.76-0.93) and as safe as VKAs with respect to major bleeding (HR, 0.83; 95% CI, 0.69-1.01). NOACs were safer with respect to the reduction of intracranial hemorrhage (HR, 0.38; 95% CI, 0.26-0.56)., Conclusions: This study-based meta-analysis shows that it may be both safer and more effective to use NOACs compared with VKAs to treat patients with nonvalvular atrial fibrillation and concomitant aspirin therapy., (© 2017 American Heart Association, Inc.)

Aim: We tested the hypothesis that left ventricular hypertrophy (LVH) interferes with the antithrombotic effects of dabigatran and warfarin in patients with atrial fibrillation (AF)., Methods and Results: This is a post-hoc analysis of the Randomized Evaluation of Long-term anticoagulation therapY (RE-LY) Study. We defined LVH by electrocardiography (ECG) and included patients with AF on the ECG tracing at entry. Hazard ratios (HR) for each dabigatran dose vs. warfarin were calculated in relation to LVH. LVH was present in 2353 (22.7%) out of 10 372 patients. In patients without LVH, the rates of primary outcome were 1.59%/year with warfarin, 1.60% with dabigatran 110 mg (HR vs. warfarin 1.01, 95% confidence interval (CI) 0.75-1.36) and 1.08% with dabigatran 150 mg (HR vs. warfarin 0.68, 95% CI 0.49-0.95). In patients with LVH, the rates of primary outcome were 3.21%/year with warfarin, 1.69% with dabigatran 110 mg (HR vs. warfarin 0.52, 95% CI 0.32-0.84) and 1.55% with 150 mg (HR vs. warfarin 0.48, 95% CI 0.29-0.78). The interaction between LVH status and dabigatran 110 mg vs. warfarin was significant for the primary outcome (P = 0.021) and stroke (P = 0.016). LVH was associated with a higher event rate with warfarin, not with dabigatran. In the warfarin group, the time in therapeutic range was significantly lower in the presence than in the absence of LVH., Conclusions: LVH was associated with a lower antithrombotic efficacy of warfarin, but not of dabigatran, in patients with AF. Consequently, the relative benefit of the lower dose of dabigatran compared to warfarin was enhanced in patients with LVH. The higher dose of dabigatran was superior to warfarin regardless of LVH status., Clinical Trial Registration: http:www.clinicaltrials.gov. Unique identifier: NCT00262600., (© The Author 2017. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Rationale: Cryptogenic ischemic strokes constitute 20-30% of ischemic strokes, the majority of which are embolic strokes of undetermined source. The standard preventive treatment in these patients is usually acetylsalicylic acid., Aim: The Randomized, double-blind, Evaluation in secondary Stroke Prevention comparing the EfficaCy and safety of the oral Thrombin inhibitor dabigatran etexilate vs. acetylsalicylic acid in patients with Embolic Stroke of Undetermined Source (RE-SPECT ESUS) is designed to determine whether the oral thrombin inhibitor dabigatran, taken within three-months after embolic stroke of undetermined source, is superior to acetylsalicylic acid for prevention of recurrent stroke and to characterize the safety of dabigatran in this setting., Design: Prospective, randomized, double-blind, multicenter trial in approximately 6000 patients and 550 centers with embolic stroke of undetermined source. Subjects are randomized to dabigatran or acetylsalicylic acid and treated for an expected minimum of six-months and up to approximately three-years. It is an event-driven trial aiming for 353 adjudicated primary outcome events., Study Outcomes: The primary efficacy outcome is time to first recurrent stroke (ischemic, hemorrhagic, or unspecified). Key secondary outcomes are time to first ischemic stroke and time to first occurrence in the composite outcome of nonfatal stroke, nonfatal myocardial infarction, and cardiovascular death. The primary safety outcome is major hemorrhage, including symptomatic intracranial hemorrhage., Discussion: Acetylsalicylic acid is the most common antithrombotic given to patients with embolic strokes of undetermined source to reduce recurrence risk. This trial will determine whether anticoagulation with dabigatran is more effective than acetylsalicylic acid, and acceptably safe., (© 2015 World Stroke Organization.)

Hypertension is frequent in patients with atrial fibrillation (AF) and is an independent risk factor for stroke. The Randomized Evaluation of Long Term Anticoagulant TherapY (RE-LY) trial found dabigatran 110 mg (D110) and 150 mg twice daily (D150) noninferior or superior to warfarin for stroke reduction in patients with AF, with either a reduction (D110) or similar rates (D150) of major bleeding. Baseline characteristics and outcomes were compared in patients with and without hypertension. The quality of blood pressure control was also assessed. In RE-LY, 14,283 patients (78.9%) had hypertension. The mean blood pressure at baseline was 132.6 ± 17.6/77.7 ± 10.6 and 124.8 ± 16.7/74.6 ± 10.0 mm Hg for patients with and without hypertension, respectively. More patients with hypertension were diabetic (25.6% vs 14.8%, p <0.001), women (38.6% vs 28.3%, p <0.001), and had greater CHADS2 (2.3 vs 1.4, p <0.001) and CHA2DS2-VASc scores (3.8 vs 2.8, p <0.001). Mean blood pressure in all treatment arms in hypertensive patients was similar (130 ± 18/76 ± 11 mm Hg) during the trial. The efficacy and safety of D110 and D150 compared to warfarin were similar (p = nonsignificant) in hypertensive (stroke/systemic embolism rate of 1.47%, 1.20%, and 1.81% and major bleed rate of 2.89%, 3.70%, and 3.69% in the D110, D150, and W, respectively) and normotensive patients (stroke/systemic embolism rate of 1.79%, 0.78%, and 1.36% and major bleed rate of 2.84%, 2.37%, and 3.03% per year in the D110, D150, and W, respectively). Hypertensive patients had more major bleeds (3.39% vs 2.76%; p = 0.007). Intracranial bleeds were similar (0.47% vs 0.31%; p = 0.12). In conclusion, patients with hypertension in RE-LY were more likely female, diabetic, with a greater CHADS2 and CHA2DS2-VASc scores. Blood pressure control in RE-LY was excellent. The benefits of dabigatran over warfarin, including a substantial reduction of intracranial hemorrhage, were similar in both hypertensive and non-hypertensive patients., (Copyright © 2015 Elsevier Inc. All rights reserved.)

In patients with atrial fibrillation (AF) who require interruption of dabigatran or warfarin for an elective surgery/procedure, the risks and benefits of perioperative bridging anticoagulation is uncertain.We accessed the database from RE-LY, a randomised trial comparing dabigatran with warfarin for stroke prevention in AF, to assess the potential benefits and risks of bridging. In patients who had a first interruption of dabigatran or warfarin for an elective surgery/procedure, we compared the risk for major bleeding (MB), stroke or systemic embolism (SSE) and any thromboembolism (TE) in patients who were bridged or not bridged during the period of seven days before until 30 days after surgery/procedure. We used multivariable Cox regression to adjust for potential confounders.Bridging was used more during warfarin interruption than dabigatran interruption (27.5 % vs 15.4 %; p< 0.001). With dabigatran interruption, bridged patients had more MB (6.5 % vs 1.8 %, p< 0.001) than those not bridged but bridged and not bridged groups did not differ for any TE (1.2 % vs 0.6 %, p=0.16) and SSE (0.5 % vs 0.3 %, p=0.46). With warfarin interruption, bridged patients had more MB (6.8 % vs 1.6 %, p< 0.001) and any TE (1.8 % vs 0.3 %, p=0.007) than those not bridged but bridged and not bridged groups did not differ for SSE (0.5 % vs 0.2 %, p=0.321). In conclusion, in patients who interrupted dabigatran or warfarin for a surgery/ procedure in the RE-LY trial, use of bridging anticoagulation appeared to increase the risk for major bleeding irrespective of dabigatran or warfarin interruption.

Background: A number of novel oral anticoagulants (direct thrombin inhibitors or factor Xa inhibitors) are in clinical use for various indications. The dosing regimens differ between twice-daily and once-daily dosing for the prevention of stroke in patients with atrial fibrillation. With the availability of the results from four phase 3 studies (>70,000 patients), we explored whether twice-daily or once-daily dosing provides better risk-benefit balance among novel oral anticoagulants., Methods: We conducted a strict, stepwise, fixed-effects meta-analysis with predefined heterogeneity quality criteria to generate the most appropriate common estimates for twice-daily (BID) or once-daily (QD) dosing regimens. An indirect comparison of these dosing regimens with fixed-effects meta-analysis common estimates (where available), or individual compound results, was done respectively., Results: Comparing indirectly BID vs QD dosing regimens resulted in hazard ratios (HR [95% confidence interval]) for stroke and systemic embolism of 0.75 (0.58-0.96) for dabigatran 150 mg BID, and 0.91 (0.73-1.13) for apixaban BID vs the QD dosing regimen. For ischemic stroke, the HR of BID vs QD was 0.85 (0.69-1.05). For intracranial hemorrhage, BID vs rivaroxaban QD was 0.57 (0.37-0.88) and, vs edoxaban QD, 0.81 (0.54-1.22). Due to heterogeneity, common estimates for major bleeding QD or BID were not justified, therefore indirect comparison of regimens were not possible. All non-vitamin K antagonist oral anticoagulants reduced all-cause mortality vs warfarin with a HR of 0.90 (0.86-0.96) without differences between regimen., Conclusions: Based on the available phase 3 study evidence, the twice-daily dosing regimen of non-vitamin K antagonist oral anticoagulants appears to offer a more balanced risk-benefit profile with respect to stroke prevention and intracranial hemorrhage.

Background: Dabigatran is an oral direct thrombin inhibitor that has been shown to be an effective alternative to warfarin in patients with atrial fibrillation. We evaluated the use of dabigatran in patients with mechanical heart valves., Methods: In this phase 2 dose-validation study, we studied two populations of patients: those who had undergone aortic- or mitral-valve replacement within the past 7 days and those who had undergone such replacement at least 3 months earlier. Patients were randomly assigned in a 2:1 ratio to receive either dabigatran or warfarin. The selection of the initial dabigatran dose (150, 220, or 300 mg twice daily) was based on kidney function. Doses were adjusted to obtain a trough plasma level of at least 50 ng per milliliter. The warfarin dose was adjusted to obtain an international normalized ratio of 2 to 3 or 2.5 to 3.5 on the basis of thromboembolic risk. The primary end point was the trough plasma level of dabigatran., Results: The trial was terminated prematurely after the enrollment of 252 patients because of an excess of thromboembolic and bleeding events among patients in the dabigatran group. In the as-treated analysis, dose adjustment or discontinuation of dabigatran was required in 52 of 162 patients (32%). Ischemic or unspecified stroke occurred in 9 patients (5%) in the dabigatran group and in no patients in the warfarin group; major bleeding occurred in 7 patients (4%) and 2 patients (2%), respectively. All patients with major bleeding had pericardial bleeding., Conclusions: The use of dabigatran in patients with mechanical heart valves was associated with increased rates of thromboembolic and bleeding complications, as compared with warfarin, thus showing no benefit and an excess risk. (Funded by Boehringer Ingelheim; ClinicalTrials.gov numbers, NCT01452347 and NCT01505881.).

Aims: We evaluated the effects of dabigatran compared with warfarin in the subgroup of patients with previous symptomatic heart failure (HF) in the RE-LY trial., Methods and Results: RE-LY compared two fixed and blinded doses of dabigatran (110 and 150 mg twice daily) with open-label warfarin in 18 113 patients with AF at increased risk for stroke. Among 4904 patients with HF, annual rates of stroke or systemic embolism (SE) were 1.92% for patients on warfarin compared with 1.90% for dabigatran 110 mg [hazard ratio (HR) 0.99, 95% confidence interval (CI) 0.69-1.42] and 1.44% for dabigatran 150 mg (HR 0.75, 95% CI 0.51-1.10). Annual rates of major bleeding were 3.90% for the group on warfarin, compared with 3.26% for dabigatran 110 mg (HR 0.83, 95% CI 0.64-1.09) and 3.10% for dabigatran 150 mg (HR 0.79, 95% CI 0.60-1.03). Rates of intracranial bleeding were significantly lower for both dabigatran dosages compared with warfarin in patients with HF (dabigatran 110 mg vs. warfarin, HR 0.34, 95% CI 0.14-0.80; dabigatran 150 mg vs. warfarin, HR 0.39, 95% CI 0.17-0.89). The relative effects of dabigatran vs. warfarin on the occurrence of stroke or SE and major bleeding were consistent among those with and without HF and those with low (≤40%) or preserved (>40%) LVEF (P interaction not significant)., Conclusions: The overall benefits of dabigatran for stroke/SE prevention, and major and intracranial bleeding, relative to warfarin in the RE-LY trial were consistent in patients with and without HF.

Background: During follow-up of between 1 and 3 years in the Randomized Evaluation of Long-term Anticoagulation Therapy (RE-LY) trial, 2 doses of dabigatran etexilate were shown to be effective and safe for the prevention of stroke or systemic embolism in patients with atrial fibrillation. There is a need for longer-term follow-up of patients on dabigatran and for further data comparing the 2 dabigatran doses., Methods and Results: Patients randomly assigned to dabigatran in RE-LY were eligible for the Long-term Multicenter Extension of Dabigatran Treatment in Patients with Atrial Fibrillation (RELY-ABLE) trial if they had not permanently discontinued study medication at the time of their final RE-LY study visit. Enrolled patients continued to receive the double-blind dabigatran dose received in RE-LY, for up to 28 months of follow up after RE-LY (median follow-up, 2.3 years). There were 5851 patients enrolled, representing 48% of patients originally randomly assigned to receive dabigatran in RE-LY and 86% of RELY-ABLE-eligible patients. Rates of stroke or systemic embolism were 1.46% and 1.60%/y on dabigatran 150 and 110 mg twice daily, respectively (hazard ratio, 0.91; 95% confidence interval, 0.69-1.20). Rates of major hemorrhage were 3.74% and 2.99%/y on dabigatran 150 and 110 mg (hazard ratio, 1.26; 95% confidence interval, 1.04-1.53). Rates of death were 3.02% and 3.10%/y (hazard ratio, 0.97; 95% confidence interval, 0.80-1.19). Rates of hemorrhagic stroke were 0.13% and 0.14%/y., Conclusions: During 2.3 years of continued treatment with dabigatran after RE-LY, there was a higher rate of major bleeding with dabigatran 150 mg twice daily in comparison with 110 mg, and similar rates of stroke and death.

Background: The Randomized Evaluation of Long-term Anticoagulation Therapy (RE-LY) trial showed that dabigatran etexilate 150 mg BID was superior and dabigatran etexilate 110 mg BID was noninferior to warfarin in preventing stroke and systemic embolism in patients with atrial fibrillation. In this subgroup analysis, we assess the efficacy and safety of dabigatran in patients who did and did not receive concomitant antiplatelets., Methods and Results: All comparisons used a Cox proportional hazards model with adjustments made for risk factors for bleeding. A time-dependent analysis was performed when comparing patients with concomitant antiplatelets with those without. Of 18 113 patients, 6952 (38.4%) received concomitant aspirin or clopidogrel at some time during the study. Dabigatran etexilate 110 mg BID was noninferior to warfarin in reducing stroke and systemic embolism, whether patients received antiplatelets (hazard ratio [HR], 0.93; 95% confidence interval [95% CI], 0.70-1.25) or not (HR, 0.87; 95% CI, 0.66-1.15; interaction P=0.738). There were fewer major bleeds than warfarin in both subgroups (HR, 0.82; 95% CI, 0.67-1.00 for patients who used antiplatelets; HR, 0.79; 95% CI, 0.64-0.96 for patients who did not; interaction P=0.794). Dabigatran etexilate 150 mg BID reduced the primary outcome of stroke and systemic embolism in comparison with warfarin. This effect seemed attenuated among patients who used antiplatelets (HR, 0.80; 95% CI, 0.59-1.08) in comparison with those who did not (HR, 0.52; 95% CI, 0.38-0.72; P for interaction=0.058). Major bleeding was similar to warfarin regardless of antiplatelet use (HR, 0.93; 95% CI, 0.76-1.12 for patients who used antiplatelets; HR, 0.94; 95% CI, 0.78-1.15 for patients who did not; P for interaction=0.875). In the time-dependent analysis, concomitant use of a single antiplatelet seemed to increase the risk of major bleeding (HR, 1.60; 95% CI, 1.42-1.82). Dual antiplatelet seemed to increased this even more (HR, 2.31; 95% CI, 1.79-2.98). The absolute risks were lowest on dabigatran etexilate 110 mg BID in comparison with dabigatran etexilate 150 mg BID or warfarin., Conclusions: Concomitant antiplatelet drugs appeared to increase the risk for major bleeding in RE-LY without affecting the advantages of dabigatran over warfarin. Choosing between dabigatran etexilate 110 mg BID and dabigatran etexilate 150 mg BID requires a careful assessment of characteristics that influence the balance between benefit and harm., Clinical Trial Registration: URL: http://clinicaltrials.gov. Unique identifier: NCT00262600.

Dabigatran etexilate is a new oral anticoagulant recently approved in Europe for the prevention of stroke or systemic embolism in adult patients with non-valvular atrial fibrillation (AF) and at least one risk factor for stroke. With a fast onset of action and a predictable anticoagulant effect obviating the need for coagulation monitoring, dabigatran etexilate offers practical advantages over vitamin K antagonists in clinical practice. However, clinicians may have questions about practical aspects of dabigatran etexilate use including monitoring anticoagulant efficacy, interruption for surgical or invasive procedures and management of bleeding. This review article aims to address these concerns and provide guidance on the use of dabigatran etexilate in special situations, such as acute coronary syndromes and cardiac revascularisation. In addition, cut-off values for different coagulation assay results associated with an increased risk of bleeding are given.

Background and Objective: Dabigatran is a new oral anticoagulant recently approved for the prevention of stroke or systemic embolism in patients with atrial fibrillation (AF). Based on its pharmacokinetic profile, dabigatran is dosed twice daily. This analysis provides a quantitative rationale for the selection of the dose regimen in this population., Methods: The pharmacokinetic profile of dabigatran was simulated for AF patients given a total daily dose of 300 mg, either once or twice daily. Simulations were based on a population pharmacokinetic model supplemented with data collected from 9522 patients enrolled in a pivotal phase III study (RE-LY)., Results: The typical RE-LY patient (male, 72 years old, Caucasian, weight 80 kg, creatinine clearance 68.64 mL/min) treated with dabigatran 150 mg twice daily showed less than two-fold difference between peak-trough plasma levels compared with a five-fold difference when the same total dose (300 mg) was administered once daily. For patients who miss or delay taking one scheduled dabigatran dose, twice daily dosing maintained adequate minimum trough concentrations better than once daily dosing. Pharmacokinetic data collected from a phase II study and RE-LY were consistent with the simulation results. The study did not access comparative efficacy and bleeding data for once versus twice daily dosing., Conclusion: Pharmacokinetic simulations show that a twice daily regimen in patients with AF minimizes daily fluctuations in plasma concentrations of dabigatran and can maintain trough concentrations sufficient to prevent the development of thrombi while at the same time minimizing the risk of bleeding due to supratherapeutic peak plasma concentrations. The efficacy and safety of this dosing regimen is supported by clinical data from the RE-LY trial.

Elderly patients with atrial fibrillation (AF), who constitute almost half of all AF patients, are at increased risk of stroke. Anticoagulant therapies, especially vitamin K antagonists (VKA), reduce the risk of stroke in all patients including the elderly but are frequently under-used in older patients. Failure to initiate VKA in elderly AF patients is related to a number of factors, including the limitations of current therapies and the increased risk for major haemorrhage associated with advanced age and anticoagulation therapy. Of particular concern is the risk of intracranial haemorrhages (ICH), which is associated with high rates of mortality and morbidity. Novel oral anticoagulant agents that are easier to use and might offer similar or better levels of stroke prevention with a similar or reduced risk of bleeding should increase the use of antithrombotic therapy in the management of elderly AF patients. Amongst these new agents, the recently approved direct thrombin inhibitor dabigatran provides effective stroke prevention with a significant reduction of ICH, and enables clinicians to tailor the dose according to age and haemorrhagic risk., (© 2011 The Association for the Publication of the Journal of Internal Medicine.)