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Background: In the BRIGHT-4 (Bivalirudin With Prolonged Full-Dose Infusion During Primary PCI Versus Heparin Trial-4), anticoagulation with bivalirudin plus a 2- to 4-hour high-dose infusion after percutaneous coronary intervention (PCI) reduced all-cause mortality and bleeding without increasing reinfarction or stent thrombosis compared with heparin alone in patients with ST-segment elevation myocardial infarction (STEMI). These findings require external validation., Objectives: This study sought to determine outcomes of bivalirudin vs heparin anticoagulation during PCI in STEMI., Methods: We performed an individual-patient-data meta-analysis of all large randomized trials of bivalirudin vs heparin in STEMI patients undergoing primary PCI performed before BRIGHT-4. The primary endpoint was all-cause mortality., Results: Six trials randomizing 15,254 patients were included. Pooled across all regimens of bivalirudin and glycoprotein IIb/IIIa inhibitor (GPI) use, bivalirudin reduced 30-day all-cause mortality (2.5% vs 2.9%; adjusted OR: 0.78; 95% CI: 0.62-0.99), cardiac mortality (adjusted OR: 0.69; 95% CI: 0.54-0.88), and major bleeding (adjusted OR: 0.53; 95% CI: 0.44-0.64) but increased reinfarction (adjusted OR: 1.30; 95% CI: 1.02-1.65) and stent thrombosis (adjusted OR: 1.43; 95% CI: 1.05-1.93) compared with heparin. In 4 trials in which 6,244 patients were randomized to bivalirudin plus a high-dose post-PCI infusion vs heparin without planned GPI use (the BRIGHT-4 regimens), 30-day all-cause mortality occurred in 1.8% vs 2.9% of patients, respectively (adjusted OR: 0.74; 95% CI: 0.48-1.12), and bivalirudin reduced cardiac mortality (adjusted OR: 0.62; 95% CI: 0.39-0.97) and major bleeding (adjusted OR: 0.49; 95% CI: 0.35-0.70), with similar rates of reinfarction (adjusted OR: 0.89; 95% CI: 0.58-1.38) and stent thrombosis (adjusted OR: 0.80; 95% CI: 0.41-1.57)., Conclusions: In STEMI patients undergoing primary PCI, bivalirudin with a 2- to 4-hour post-PCI high-dose infusion reduced cardiac mortality and major bleeding without an increase in ischemic events compared with heparin monotherapy with provisional GPI use, confirming the BRIGHT-4 results., Competing Interests: Funding Support and Author Disclosures The present study was supported by a research grant from The Medicines Company to the Cardiovascular Research Foundation. Dr Bikdeli is supported by the Scott Schoen and Nancy Adams IGNITE Award from the Mary Horrigan Connors Center for Women’s Health and Gender Biology at Brigham and Women’s Hospital, and a Career Development Award from the American Heart Association and VIVA Physicians (#938814). Dr Stone has received speaker honoraria from Medtronic, Pulnovo, and Infraredx; has served as a consultant to Valfix, TherOx, Robocath, HeartFlow, Ablative Solutions, Vectorious, Miracor, Neovasc, Abiomed, Ancora, Elucid Bio, Occlutech, CorFlow, Apollo Therapeutics, Impulse Dynamics, Cardiomech, Gore, Amgen, Adona Medical, and Millennia Biopharma; and has equity/options from Ancora, Cagent, Applied Therapeutics, Biostar family of funds, SpectraWave, Orchestra Biomed, Aria, Cardiac Success, Valfix, and Xenter. Dr Stone’s employer, Mount Sinai Hospital, receives research support from Abbott, Abiomed, Bioventrix, Cardiovascular Systems Inc, Phillips, Biosense Webster, Shockwave, Vascular Dynamics, Pulnovo, and V-wave. Dr Valgimigli has received grants from Terumo; and has received personal fees from AstraZeneca, Alvimedica/CID, Abbott Vascular, Daiichi-Sankyo, Bayer, CorFlow, Idorsia Pharmaceuticals, Universität Basel Dept Klinische Forschung, Bristol Myers Squibb SA, Medscape, Biotronik, and Novartis, outside the submitted work. Dr Erlinge has received honoraria for advisory boards from AstraZeneca, Bayer, Chiesi, and Sanofi; and has received speaker honoraria from Bayer, AZ, Novartis, and Chiesi. Dr Steg has received research grants from Amarin, AstraZeneca, Bayer, Sanofi, and Servier; and has received honoraria for clinical trials (serving on the steering committee, clinical endpoint committee, data and safety monitoring committee) from Amarin, AstraZeneca, Bayer, Bristol Myers Squibb, Idorsia, Novartis, PhaseBio, Pfizer, Sanofi, Servier, and The Medicines Company; has received fees for consulting or speaking from Amarin, Amgen, BMS, Novo Nordisk, and Regeneron; and is a Senior Associate Editor at Circulation. Dr James’s employer has received research grants from Novartis, Amgen, Janssen, Bayer, AstraZeneca, and Infraredex. Dr Mehran has received institutional research funding from Abbott, Abiomed, Alleviant Medical, AM-Pharma, Amgen, Applied Therapeutics, Arena, AstraZeneca, AtriCure, Bayer, Biosensors, Biotronik, Boston Scientific, Bristol Myers Squibb, CardiaWave, CeloNova, Chiesi, Concept Medical, CSL Behring, Cytosorbents, Daiichi-Sankyo, Element Science, Faraday, Humacyte, Idorsia, Janssen, Magenta, Medtronic, Novartis, OrbusNeich, PhaseBio, Philips, Pi-Cardia, RenalPro, RM Global, Shockwave, Vivasure, and Zoll; has received personal fees from Cine-Med Research and WebMD; holds equity in Applied Therapeutics, Elixir Medical, and Stel; has served on scientific advisory boards for the AMA, ACC (BOT member), and SCAI (Women in Innovations Committee member); has served as an associate editor of JAMA; is an unpaid member of the faculty of CRF; and her spouse has received personal fees from ControlRad. Dr Bikdeli has been a consulting expert, on behalf of the plaintiff, for litigation related to 2 brand models of IVC filters. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: The value of prolonged bivalirudin infusion after percutaneous coronary intervention (PCI) in acute coronary syndrome (ACS) patients with or without ST-segment elevation remains unclear., Objectives: The purpose of this study was to assess efficacy and safety of a full or low post-PCI bivalirudin regimen in ACS patients with or without ST-segment elevation., Methods: The MATRIX program assigned bivalirudin to patients without or with a post-PCI infusion at either a full (1.75 mg/kg/h for ≤4 h) or reduced (0.25 mg/kg/h for ≤6 h) regimen at the operator's discretion. The primary endpoint was the 30-day composite of urgent target-vessel revascularization, definite stent thrombosis, or net adverse clinical events (composite of all-cause death, myocardial infarction, or stroke, or major bleeding)., Results: Among 3,610 patients assigned to bivalirudin, 1,799 were randomized to receive and 1,811 not to receive a post-PCI bivalirudin infusion. Post-PCI full bivalirudin was administered in 612 (ST-segment elevation myocardial infarction [STEMI], n = 399; non-ST-segment elevation acute coronary syndromes [NSTE-ACS], n = 213), whereas the low-dose regimen was administered in 1,068 (STEMI, n = 519; NSTE-ACS, n = 549) patients. The primary outcome did not differ in STEMI or NSTE-ACS patients who received or did not receive post-PCI bivalirudin. However, full compared with low bivalirudin regimen remained associated with a significant reduction of the primary endpoint after multivariable (rate ratio: 0.21; 95% CI: 0.12 to 0.35; p < 0.001) or propensity score (rate ratio: 0.16; 95% CI: 0.09 to 0.26; p < 0.001) adjustment. Full post-PCI bivalirudin was associated with improved outcomes consistently across ACS types compared with the no post-PCI infusion or heparin groups., Conclusions: In ACS patients with or without ST-segment elevation, the primary endpoint did not differ with or without post-PCI bivalirudin infusion but a post-PCI full dose was associated with improved outcomes when compared with no or low-dose post-PCI infusion or heparin (Minimizing Adverse Haemorrhagic Events by TRansradial Access Site and Systemic Implementation of angioX [MATRIX]; NCT01433627)., (Copyright © 2019 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: The optimal treatment strategy when combining antiplatelets with oral anticoagulants in patients with atrial fibrillation (AF) and myocardial infarction (MI) or undergoing percutaneous coronary intervention (PCI) is unknown., Objectives: The authors investigated the risk of bleeding, ischemic stroke, MI, and all-cause mortality associated with direct oral anticoagulants (DOACs) compared with vitamin K antagonists (VKAs) in combination with aspirin, clopidogrel, or both in patients with AF following MI and/or PCI., Methods: Danish nationwide registries were used to identify patients with AF who were admitted with a MI and/or underwent PCI, between August 2011 and June 2017, treated with OAC in combination with antiplatelet(s). Patients were followed for 12 months or until an outcome, study end, or death. Standardized absolute risks were estimated on the basis of outcome-specific Cox regression models adjusted for potential confounders. Average treatment effects were obtained as standardized absolute risk differences (ARD) in risks at 3 and 12 months using the g-formula., Results: Overall, 3,222 patients were included in the study population, of which 875 (27%) were treated with VKA+single antiplatelet therapy (SAPT), 595 (18%) were treated with DOAC+SAPT, 1,074 (33%) were treated with VKA+dual antiplatelet therapy (DAPT), and 678 (22%) were treated with DOAC+DAPT. At 3 months, there was a significant difference in the absolute risk of MI associated with DOAC+SAPT compared with VKA+SAPT (3-month ARD -1.53% (95% confidence interval: -3.08% to -0.11%), with no significant differences found regarding bleeding, ischemic stroke, and all-cause mortality. Compared with VKA+DAPT, DOAC+DAPT was associated with a significantly reduced risk of bleeding (3-month ARD -1.96%, 95% confidence interval: -3.46% to -0.88%), with no significant difference in the absolute risk of all-cause mortality, stroke, or MI., Conclusions: In a real-world population of AF patients with MI and/or after PCI, the authors found that DOAC in combination with DAPT was associated with a significantly decreased risk of bleeding and similar thromboembolic protection compared with VKA in combination with DAPT., (Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Women with atrial fibrillation are at a higher risk of stroke, despite treatment with warfarin. It is unclear if women treated with direct oral anticoagulants (DOACs) have better clinical outcomes, especially when considering the quality of anticoagulation control of warfarin., Objectives: This study compared the effectiveness and safety outcomes of DOACs versus warfarin in men and women with stratifications for anticoagulation control., Methods: Patients newly diagnosed with atrial fibrillation and prescribed oral anticoagulants during 2010 to 2015 were identified using the Hong Kong clinical database. Propensity score matching was performed in men and women separately. Further analysis was conducted to stratify warfarin users according to their anticoagulation control. Cox regression was used to compare the risk of ischemic stroke or systemic embolism, intracranial hemorrhage (ICH), gastrointestinal bleeding, and all-cause mortality in the specific sex., Results: There were 4,972 men and 4,834 women successfully matched in our cohort. Compared with warfarin, DOAC use was associated with a lower risk of ICH (hazard ratio [HR]: 0.16; 95% confidence interval [CI]: 0.06 to 0.40) and all-cause mortality (HR: 0.55; 95% CI: 0.39 to 0.77) in women but not in men. The treatment by sex interaction was significant for ICH only, and a significantly lower risk of ICH remained in the DOAC group when compared with warfarin users with good anticoagulation control (HR: 0.13; 95% CI: 0.02 to 1.00) among women only. The risks of ischemic stroke or systemic embolism and gastrointestinal bleeding with DOACs versus warfarin were comparable in both sexes., Conclusions: DOACs were associated with a lower risk of ICH and all-cause mortality in women only, where the association of lower ICH risk remained when compared with warfarin users with good anticoagulation control., (Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Dose reduction of non-vitamin K antagonist oral anticoagulants (NOACs) is indicated in patients with atrial fibrillation (AF) with renal impairment. Failure to reduce the dose in patients with severe kidney disease may increase bleeding risk, whereas dose reductions without a firm indication may decrease the effectiveness of stroke prevention., Objectives: The goal of this study was to investigate NOAC dosing patterns and associated outcomes, i.e., stroke (ischemic stroke and systemic embolism) and major bleeding in patients treated in routine clinical practice., Methods: Using a large U.S. administrative database, 14,865 patients with AF were identified who initiated apixaban, dabigatran, or rivaroxaban between October 1, 2010, and September 30, 2015. We examined use of a standard dose in patients with a renal indication for dose reduction (potential overdosing) and use of a reduced dose when the renal indication is not present (potential underdosing). Cox proportional hazards regression was performed in propensity score-matched cohorts to investigate the outcomes., Results: Among the 1,473 patients with a renal indication for dose reduction, 43.0% were potentially overdosed, which was associated with a higher risk of major bleeding (hazard ratio: 2.19; 95% confidence interval: 1.07 to 4.46) but no statistically significant difference in stroke (3 NOACs pooled). Among the 13,392 patients with no renal indication for dose reduction, 13.3% were potentially underdosed. This underdosing was associated with a higher risk of stroke (hazard ratio: 4.87; 95% confidence interval: 1.30 to 18.26) but no statistically significant difference in major bleeding in apixaban-treated patients. There were no statistically significant relationships in dabigatran- or rivaroxaban-treated patients without a renal indication., Conclusions: In routine clinical practice, prescribed NOAC doses are often inconsistent with drug labeling. These prescribing patterns may be associated with worse safety with no benefit in effectiveness in patients with severe kidney disease and worse effectiveness with no benefit in safety in apixaban-treated patients with normal or mildly impaired renal function., (Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Whether dabigatran is associated with a lower risk of acute kidney injury (AKI) in patients with nonvalvular atrial fibrillation (NVAF) remains unknown., Objectives: The authors compared the risk of AKI in Asians with NVAF who were prescribed dabigatran versus warfarin., Methods: The authors analyzed patients enrolled in the Taiwan nationwide retrospective cohort study from June 1, 2012, to December 31, 2013. Dabigatran and warfarin were taken by 7,702 and 7,885 NVAF patients without a history of chronic kidney disease (CKD) and 2,256 and 2,089 NVAF patients with a history of CKD, respectively. A propensity-score weighted method was used to balance covariates across study groups., Results: A total of 6,762 (88%) and 940 (12%) CKD-free patients and 2,025 (90%) and 231 (10%) CKD patients took dabigatran 110 mg and 150 mg twice daily, respectively. Dabigatran was associated with a lower risk of AKI than warfarin for either the CKD-free (hazard ratio [HR]: 0.62; 95% confidence interval [CI]: 0.49 to 0.77; p < 0.001) or CKD (HR: 0.56; 95% CI: 0.46 to 0.69; p < 0.001) cohort. As the increment in CHA 2 DS 2 -VASc score (a risk score based on congestive heart failure, hypertension, age 75 years or older, diabetes mellitus, previous stroke/transient ischemic attack, vascular disease, aged 65 to 74 years, and female sex) increased from 0/1 to 6+ points, the incidence of AKI for the dabigatran group was relatively stable (1.87% to 2.91% per year for the CKD-free cohort; 7.31% to 13.15% per year for the CKD cohort) but increased obviously for patients taking warfarin for either CKD-free (2.00% to 6.16% per year) or CKD cohorts (6.82 to 26.03% per year). The warfarin group had a significantly higher annual risk of AKI than the dabigatran group for those with a high CHA 2 DS 2 -VASc score (≥4 for the CKD-free cohort and ≥3 for the CKD cohort). Subgroup analysis revealed that among dabigatran users, those taking either low-dose or standard-dose dabigatran, those with a warfarin-naïve or warfarin-experienced history, those with or without diabetes, and those with CHA 2 DS 2 -VASc ≥4 or HAS-BLED ≥3 (risk score based on hypertension, abnormal renal and liver function, stroke, prior major bleeding, labile international normalized ratios, age 65 years or older, drugs or alcohol usage history) all had a lower risk of AKI than those taking warfarin., Conclusions: Among Asians with NVAF, dabigatran is associated with a lower risk of AKI than warfarin., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Cerebral embolization is a frequent complication after transcatheter aortic valve replacement (TAVR). We hypothesized that cerebral embolization may be reduced by anticoagulation with bivalirudin during TAVR., Objectives: This study sought to determine the proportion of patients with new cerebral embolus after TAVR and to investigate whether parenteral procedural anticoagulation strategies affect cerebral embolization., Methods: The BRAVO (Effect of Bivalirudin on Aortic Valve Intervention Outcomes)-3 randomized trial compared bivalirudin with unfractionated heparin in patients undergoing transfemoral TAVR. A prospective cerebral magnetic resonance imaging (MRI) substudy was conducted in 4 sites; 60 patients were imaged with brain MRI after TAVR. Primary endpoint was proportion of patients with new cerebral emboli on MRI. Secondary endpoints included quantitative MRI analyses of cerebral lesions and neurological outcomes at 48 h and 30 days., Results: Patients were randomized to bivalirudin (n = 29) versus heparin (n = 31). The proportion of patients with new cerebral emboli on MRI did not differ between bivalirudin and heparin groups (65.5% vs. 58.1%; p = 0.55). Groups were similar for median number of emboli per patient (1 [interquartile range (IQR): 0 to 3] vs. 1 [IQR: 0 to 1]; p = 0.08), total volume of emboli (45 [IQR: 0 to 175] mm(3) vs. 33 [IQR: 0 to 133] mm(3); p = 0.86), or proportion of patients with a clinical neurological deficit at 48 h or 30 days. All patients who presented clinically with stroke had evidence of new emboli on MRI., Conclusions: This study documented cerebral embolization in nearly two-thirds of patients during contemporary TAVR. There were no significant differences in cerebral embolization for bivalirudin versus heparin anticoagulation during TAVR. (Open-Label, Randomized Trial in Patients Undergoing TAVR to Determine Safety and Efficacy of Bivalrudin vs. UFH [BRAVO-2/3]; NCT01651780)., (Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Anticoagulation is required during transcatheter aortic valve replacement (TAVR) procedures. Although an optimal regimen has not been determined, heparin is mainly used. Direct thrombin inhibition with bivalirudin may be an effective alternative to heparin as the procedural anticoagulant agent in this setting., Objectives: The goal of this study was to determine whether bivalirudin offers an alternative to heparin as the procedural anticoagulant agent in patients undergoing TAVR., Methods: A total of 802 patients with aortic stenosis were randomized to undergo transfemoral TAVR with bivalirudin versus unfractionated heparin during the procedure. The 2 primary endpoints were major bleeding within 48 h or before hospital discharge (whichever occurred first) and 30-day net adverse clinical events, defined as the combination of major adverse cardiovascular events (all-cause mortality, myocardial infarction, or stroke) and major bleeding., Results: Anticoagulation with bivalirudin versus heparin did not meet superiority because it did not result in significantly lower rates of major bleeding at 48 h (6.9% vs. 9.0%; relative risk: 0.77; 95% confidence interval [CI]: 0.48 to 1.23; p = 0.27) or net adverse cardiovascular events at 30 days (14.4% vs. 16.1%; relative risk: 0.89; 95% CI: 0.64 to 1.24; risk difference: -1.72; 95% CI: -6.70 to 3.25; p = 0.50); regarding the latter, the prespecified noninferiority hypothesis was met (pnoninferiority < 0.01). Rates of major adverse cardiovascular events at 48 h were not significantly different (3.5% vs. 4.8%; relative risk: 0.73; 95% CI: 0.37 to 1.43; p = 0.35). At 48 h, the bivalirudin group had significantly fewer myocardial infarctions but more acute kidney injury events than the heparin group; at 30 days, these differences were no longer significant., Conclusions: In this randomized trial of TAVR procedural pharmacotherapy, bivalirudin did not reduce rates of major bleeding at 48 h or net adverse cardiovascular events within 30 days compared with heparin. Although superiority was not shown, the noninferiority hypothesis was met with respect to the latter factor. Given the lower cost, heparin should remain the standard of care, and bivalirudin can be an alternative anticoagulant option in patients unable to receive heparin in TAVR. (International, Multi-center, Open-label, Randomized Controlled Trial in Patients Undergoing TAVR to Determine the Treatment Effect [Both Safety and Efficacy] of Using Bivalirudin Instead of UFH [BRAVO-2/3]; NCT01651780)., (Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Non-vitamin K oral anticoagulants (NOACs) do not require routine laboratory monitoring. However, laboratory measurement may be desirable in special situations and populations., Objectives: This study's objective was to systematically review and summarize current evidence regarding laboratory measurement of the anticoagulant activity of dabigatran, rivaroxaban, and apixaban., Methods: We searched PubMed and Web of Science for studies that reported a relationship between drug levels of dabigatran, rivaroxaban, and apixaban and coagulation assay results. Study quality was evaluated using QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies 2)., Results: We identified 17 eligible studies for dabigatran, 15 for rivaroxaban, and 4 for apixaban. For dabigatran, a normal thrombin time excludes clinically relevant drug concentrations. The activated partial thromboplastin time (APTT) and prothrombin time (PT) are less sensitive and may be normal at trough drug levels. The dilute thrombin time (R(2) = 0.92 to 0.99) and ecarin-based assays (R(2) = 0.92 to 1.00) show excellent linearity across on-therapy drug concentrations and may be used for drug quantification. For rivaroxaban and apixaban, anti-Xa activity is linear (R(2) = 0.89 to 1.00) over a wide range of drug levels and may be used for drug quantification. Undetectable anti-Xa activity likely excludes clinically relevant drug concentrations. The PT is less sensitive (especially for apixaban); a normal PT may not exclude clinically relevant levels. The APTT demonstrates insufficient sensitivity and linearity for quantification., Conclusions: Dabigatran, rivaroxaban, and apixaban exhibit variable effects on coagulation assays. Understanding these effects facilitates interpretation of test results in NOAC-treated patients. More information on the relationship between drug levels and clinical outcomes is needed., (Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: The goal of this study was to analyze the impact of dabigatran plasma concentrations, patient demographics, and aspirin (ASA) use on frequencies of ischemic strokes/systemic emboli and major bleeds in atrial fibrillation patients., Background: The efficacy and safety of dabigatran etexilate were demonstrated in the RE-LY (Randomized Evaluation of Long-Term Anticoagulation Therapy) trial, but a therapeutic concentration range has not been defined., Methods: In a pre-specified analysis of RE-LY, plasma concentrations of dabigatran were determined in patients treated with dabigatran etexilate 110 mg twice daily (bid) or 150 mg bid and correlated with the clinical outcomes of ischemic stroke/systemic embolism and major bleeding using univariate and multivariate logistic regression and Cox regression models. Patient demographics and ASA use were assessed descriptively and as covariates., Results: Plasma concentrations were obtained from 9,183 patients, with 112 ischemic strokes/systemic emboli (1.3%) and 323 major bleeds (3.8%) recorded. Dabigatran levels were dependent on renal function, age, weight, and female sex, but not ethnicity, geographic region, ASA use, or clopidogrel use. A multiple logistic regression model (c-statistic 0.657, 95% confidence interval [CI]: 0.61 to 0.71) showed that the risk of ischemic events was inversely related to trough dabigatran concentrations (p = 0.045), with age and previous stroke (both p < 0.0001) as significant covariates. Multiple logistic regression (c-statistic 0.715, 95% CI: 0.69 to 0.74) showed major bleeding risk increased with dabigatran exposure (p < 0.0001), age (p < 0.0001), ASA use (p < 0.0003), and diabetes (p = 0.018) as significant covariates., Conclusions: Ischemic stroke and bleeding outcomes were correlated with dabigatran plasma concentrations. Age was the most important covariate. Individual benefit-risk might be improved by tailoring dabigatran dose after considering selected patient characteristics. (Randomized Evaluation of Long Term Anticoagulant Therapy [RE-LY] With Dabigatran Etexilate; NCT00262600)., (Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: The purpose of this study was to determine whether, in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI), the reduction in cardiac mortality in those taking bivalirudin compared with unfractionated heparin plus a glycoprotein IIb/IIIa inhibitor (UFH+GPI) can be fully attributed to reduced bleeding., Background: The association between hemorrhagic complications and mortality may explain the survival benefit with bivalirudin., Methods: A total of 3,602 STEMI patients undergoing primary PCI were randomized to bivalirudin versus UFH+GPI. Three-year cardiac mortality was analyzed in patients with and without major bleeding., Results: When compared with UFH+GPI, bivalirudin resulted in lower 3-year rates of major bleeding (6.9% vs. 10.5%, hazard ratio [HR]: 0.64 [95% confidence interval (CI): 0.51 to 0.80], p < 0.0001) and cardiac mortality (2.9% vs. 5.1%, HR: 0.56 [95% CI: 0.40 to 0.80], p = 0.001). Three-year cardiac mortality was reduced in bivalirudin-treated patients with major bleeding (20 fewer deaths with bivalirudin; 5.8% vs. 14.6%, p = 0.025) and without major bleeding (18 fewer deaths with bivalirudin; 2.6% vs. 3.8%, p = 0.048). In a fully-adjusted multivariable model accounting for major bleeding and other adverse events, bivalirudin was still associated with a 43% reduction in 3-year cardiac mortality (adjusted HR: 0.57 [95% CI: 0.39 to 0.83], p = 0.003)., Conclusions: Bivalirudin reduces cardiac mortality in patients with STEMI undergoing primary PCI, an effect that can only partly be attributed to prevention of bleeding. Further studies are required to identify the nonhematologic benefits of bivalirudin. (Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction; NCT00433966)., (Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: This study sought to compare the net clinical benefit of dabigatran 110 mg bid and 150 mg bid with that of warfarin in patients with atrial fibrillation (AF)., Background: In patients with AF, dabigatran 110 mg bid and 150 mg bid are associated with similar rates of death. However, the higher dose reduces ischemic stroke and increases bleeding compared with the lower dose. Therefore, there is uncertainty about how to evaluate the overall benefit of the 2 doses., Methods: In 18,113 AF patients in the RE-LY (Randomized Evaluation of Long Term Anticoagulant Therapy) trial, we used a previously developed method for integrating ischemic and bleeding events as "ischemic stroke equivalents" in order to compare a weighted benefit of 2 doses of dabigatran with each other, and with that of warfarin., Results: Compared with warfarin, there was a significant decrease in ischemic stroke equivalents with both dabigatran doses: -0.92 per 100 patient years (95% confidence interval [CI]: -1.74 to -0.21, p = 0.02) with dabigatran 110 mg bid and -1.08 (95% CI: -1.86 to -0.34, p = 0.01) with dabigatran 150 mg bid. There was no significant difference in ischemic stroke equivalents between the 2 doses: -0.16 (95% CI: -0.80 to 0.43) comparing dabigatran 150 mg bid with 110 bid. When including death in the weighted benefit calculations, the results were similar., Conclusions: On a group level both doses of dabigatran as compared with warfarin have similar benefits when considering a weighted estimate including both efficacy and safety. The similar overall benefits of the 2 doses of dabigatran versus warfarin support individualizing the dose based on patient characteristics and physician and patient preferences. (Randomized Evaluation of Long Term Anticoagulant Therapy [RE-LY] With Dabigatran Etexilate; NCT00262600)., (Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: This study sought to assess whether incorporation of routine bleeding risk estimates affected the utilization of bivalirudin during percutaneous coronary intervention (PCI)., Background: Bivalirudin use during PCI has been shown to reduce bleeding complications. However, a risk-treatment paradox exists, in which patients at highest risk for bleeding are least likely to receive bivalirudin. Whether routine estimation of individualized bleeding risk can affect physicians' use of bivalirudin is unknown., Methods: PCI data from a single health system between 2007 and 2011 were analyzed. Beginning in July 2009, individualized bleeding risk estimates were provided immediately preceding PCI. Using a pre-post design, we compared bivalirudin use before and after this implementation, for patients across 3 strata of bleeding risk (<1%, 1% to 3%, and >3%)., Results: Data from 6,491 PCI procedures were analyzed. Overall, bivalirudin use increased in the post-implementation period (26.9% vs. 34.2%, p < 0.001). Bivalirudin use increased in intermediate (27% to 35%, p < 0.001) and high bleeding risk patients (25% to 43%, p < 0.001), and decreased in low-risk patients (30% to 25%, p = 0.014). During the same period, bleeding complications decreased in intermediate-risk (3.4% to 1.8%, p = 0.009) and high-risk (6.9% to 3.7%, p = 0.005) patients and remained unchanged in low-risk patients (1.1% to 1.0%, p = 0.976)., Conclusions: There was an increase in bivalirudin use and a lower incidence of bleeding after the incorporation of individualized bleeding risk estimates into clinical practice. This implementation led to a reversal of the risk-treatment paradox, through a rational increase in bivalirudin use in patients at intermediate and high bleeding risk and decreased use in lower-risk patients., (Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: We investigated the outcomes of switching to bivalirudin after initial administration of heparin in patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention., Background: Unfractionated heparin (UFH) is frequently administered early in ST-segment elevation myocardial infarction. Whether the benefits of bivalirudin documented in the HORIZONS-AMI (Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction) trial persist in patients previously administered UFH is unknown., Methods: We analyzed the outcomes of the 2,357 patients from HORIZONS-AMI treated with UFH before enrollment according to their subsequent randomization to bivalirudin (switch group, n = 1,178) or UFH plus a glycoprotein IIb/IIIa inhibitor (control group, n = 1,179)., Results: At 30 days, major bleeding occurred in 7.6% of the switch group versus 12.3% of the control group (p = 0.0001). Switch patients had lower 30-day rates of cardiac mortality (1.6% vs. 2.9%, p = 0.04). At 2-year follow-up, switch patients experienced lower rates of major bleeding (8.4% vs. 13.0%, p = 0.0003), cardiac mortality (2.3% vs. 3.8%, p = 0.04), and reinfarction (4.0% vs. 7.1%, p = 0.0002). Two-year rates of definite/probable stent thrombosis were similar in switch and control patients (3.1% vs. 4.3%, p = 0.17)., Conclusions: In ST-segment elevation myocardial infarction patients who receive early treatment with UFH, switching to bivalirudin before primary percutaneous coronary intervention results in reduced rates of major bleeding and improved early and late cardiac survival., (Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: We sought to show that hirudin might interact differently with streptokinase (SK) and tissue-type plasminogen activator (t-PA), which could reduce the incidence of death or reinfarction at 30 days., Background: In a large-scale trial of patients with acute coronary syndromes, hirudin provided modest benefit compared with heparin. However, the interaction with thrombolytic agents was not specifically assessed., Methods: Patients with symptoms of acute myocardial infarction and electrocardiographic ST segment elevation were treated with thrombolytic therapy and randomly assigned to receive hirudin or heparin., Results: A total of 2,274 patients received t-PA, and 1,015 received SK. Baseline characteristics were balanced by antithrombin assignment. Among SK-treated patients, death or reinfarction at 30 days occurred more often in those treated with adjunctive heparin (14.4%) rather than hirudin (8.6%, odds ratio [OR] 1.78, 95% confidence interval [CI] 1.20 to 2.66, p = 0.004). Among t-PA-treated patients, the rates were 10.9% with heparin and 10.3% with hirudin (OR 1.06, 95% CI 0.81 to 1.38, p = 0.68; for treatment heterogeneity: chi-square 4.20, degrees of freedom [df] 1, p = 0.04). After adjustment for baseline differences between thrombolytic groups, the rates were 9.1% for SK with hirudin, 10.3% for t-PA with hirudin, 10.5% for t-PA with heparin and 14.9% for SK with heparin (for treatment heterogeneity: chi-square 4.5, df 1, p = 0.03), suggesting that the beneficial treatment effect of hirudin was limited to the SK-treated patients., Conclusions: Hirudin interacts favorably with SK but not t-PA, highlighting the importance of thrombin activity after SK therapy and the potential for simulating the effects of a more potent fibrinolytic agent through direct antithrombin therapy.

Objectives: This study evaluated the efficacy of local administration of an antithrombin agent with a hydrogel-coated percutaneous transluminal coronary angioplasty balloon catheter., Background: Intravenous infusion of antithrombin compounds has been shown to inhibit platelet-dependent thrombosis. However, hemorrhage is a common side effect associated with the systemic administration of antithrombin compounds., Methods: The potent, irreversible thrombin inhibitor D-Phe-L-Pro-L-Arginyl chloromethyl ketone (PPACK) was used to inhibit thrombus formation in chronic porcine arteriovenous shunts. Platelet deposition was quantitated with gamma camera imaging of 111In-labeled platelets., Results: Intravenous administration of PPACK in swine, in doses sufficient to maximally inhibit thrombus formation, was associated with prolongation of bleeding parameters. The inhibition of thrombosis associated with intravenous PPACK was dose related. The amount of intravenous PPACK necessary for maximal inhibition of thrombus formation for a period of 45 min was 16.9 mg. In contrast, local delivery of PPACK with a hydrogel-coated angioplasty balloon deployed at the site of the thrombus inhibited platelet deposition for at least 45 min after the balloon was removed. Using 3H-labeled PPACK, the calculated amount of PPACK delivered was 33.5 micrograms. There was no change in bleeding time or activated partial thromboplastin time when swine received an intravenous bolus greater than the total amount of PPACK adsorbed onto the balloon (70 micrograms)., Conclusions: These results suggest that in this model, a hydrogel-coated coronary angioplasty balloon catheter can be used to deliver enough antithrombin agent to inhibit platelet-dependent thrombosis for at least 45 min at doses that are several orders of magnitude less than those required for systemic administration. In addition, local delivery can provide effective inhibition of thrombus formation without alteration of bleeding parameters.

Objectives: In a Phase I clinical trial, we studied the antithrombotic and clinical effects of the synthetic competitive thrombin inhibitor, argatroban, in 43 patients with unstable angina pectoris., Background: Thrombin has a pivotal role in platelet-mediated thrombosis associated with atheromatous plaque rupture in patients with an acute ischemic coronary syndrome. However, the efficacy of conventional heparin therapy to prevent ischemic events is limited and has been surpassed by that of specific thrombin inhibitors in experimental models of arterial thrombosis., Methods: Intravenous infusion of the drug (0.5 to 5.0 micrograms/kg per min) for 4 h was monitored by sequential measurements of coagulation times and of indexes of thrombin activity in vivo followed by a 24-h clinical observation period., Results: Significant dose-related increases in plasma drug concentrations and activated partial thromboplastin times (aPTT), but no bleeding time prolongation or spontaneous bleeding, was observed. Myocardial ischemia did not occur during therapy but, surprisingly, 9 of the 43 patients experienced an episode of unstable angina 5.8 +/- 2.6 h (mean +/- SD) after infusion. This early recurrent angina was correlated significantly with a higher argatroban dose and with greater prolongation of aPTT but not with other demographic, clinical, laboratory and angiographic characteristics. Pretreatment plasma concentrations of thrombin-antithrombin III complex and fibrinopeptide A were elevated two to three times above normal values. During infusion, thrombin-antithrombin III complex levels remained unchanged, whereas a significant 2.3-fold decrease in fibrinopeptide A concentrations was observed. By contrast, 2 h after infusion, thrombin-antithrombin III complex concentrations increased 3.9-fold over baseline measurements together with return of fibrinopeptide A levels to values before treatment with argatroban., Conclusions: In patients with unstable angina, argatroban inhibits clotting (aPTT prolongation) and thrombin activity toward fibrinogen (fibrinopeptide A decrease), but in vivo thrombin (thrombin-antithrombin III complex) formation is not suppressed. However, cessation of infusion is associated with rebound thrombin (thrombin-antithrombin III complex) generation and with an early dose-related recurrence of unstable angina. Although the mechanism of this clinical and biochemical rebound phenomenon remains to be determined, its implication for the clinical use of specific thrombin inhibitors in the management of ischemic coronary syndromes may be significant.