Effectiveness and Safety of Apixaban, Dabigatran, and Rivaroxaban Versus Warfarin in Frail Patients With Nonvalvular Atrial Fibrillation.

Frailty predicts poorer outcomes and decreased anticoagulation use in patients with nonvalvular atrial fibrillation. We sought to assess the effectiveness and safety of apixaban, dabigatran and rivaroxaban versus warfarin in frail nonvalvular atrial fibrillation patients. Using US MarketScan claims data from November 2011 to December 2016, we identified frail oral anticoagulant-naïve nonvalvular atrial fibrillation patients with ≥12 months of continuous insurance coverage before oral anticoagulant initiation. Frailty status was determined using the Johns Hopkins Claims-based Frailty Indicator score (≥0.20 indicating frailty). Users of apixaban, dabigatran, or rivaroxaban were separately 1:1 matched to warfarin users via propensity-scores, with residual absolute standardized differences <0.1 being achieved for all covariates after matching. Patients were followed for up to 2 years or until an event, insurance disenrollment or end of follow-up. Rates of stroke or systemic embolism and major bleeding were compared using Cox regression and reported as hazard ratios (HRs) and 95% confidence intervals (CIs). In total, 2700, 2784, and 5270 patients were included in the apixaban, dabigatran, and rivaroxaban 1:1 matched analyses to warfarin. At 2 years, neither apixaban nor dabigatran were associated with differences in the hazard of stroke or systemic embolism (HR=0.78; 95% CI=0.46-1.35 and HR=0.94; 0.60-1.45) or major bleeding (HR=0.72; 95% CI=0.49-1.06 and HR=0.87; 95% CI=0.63-1.19) versus warfarin. Rivaroxaban was associated with reduced stroke or systemic embolism at 2 years (HR=0.68; 95% CI=0.49-0.95) without significantly altering major bleeding risk (HR=1.07; 95% CI=0.81-1.32). Our study found rivaroxaban but not apixaban or dabigatran to be associated with reduced SSE versus warfarin in frail nonvalvular atrial fibrillation patients. No direct-acting oral anticoagulants demonstrated a significant difference in major bleeding versus warfarin.

Martinez BK ，Sood NA ，Bunz TJ ，Coleman CI ... -  《Journal of the American Heart Association》

Effectiveness and Safety of Apixaban, Dabigatran, and Rivaroxaban Versus Warfarin in Patients With Nonvalvular Atrial Fibrillation and Previous Stroke or Transient Ischemic Attack.

Limited real-world data exist comparing each non-vitamin K antagonist oral anticoagulant (NOAC) to warfarin in patients with nonvalvular atrial fibrillation who have had a previous ischemic stroke or transient ischemic attack. Using MarketScan claims from January 2012 to June 2015, we identified adults newly initiated on oral anticoagulation, with ≥2 diagnosis codes for nonvalvular atrial fibrillation, a history of previous ischemic stroke/transient ischemic attack, and ≥180 days of continuous medical and prescription benefits before anticoagulation initiation. Three analyses were performed comparing 1:1 propensity score-matched cohorts of apixaban versus warfarin (n=2514), dabigatran versus warfarin (n=1962), and rivaroxaban versus warfarin (n=5208). Patients were followed until occurrence of a combined end point of ischemic stroke and intracranial hemorrhage (ICH) or major bleed, switch/discontinuation of index oral anticoagulation, insurance disenrollment, or end of follow-up. Mean follow-up was 0.5 to 0.6 years for all matched cohorts. Using Cox regression, neither apixaban nor dabigatran reduced the combined primary end point of ischemic stroke or ICH (hazard ratio [HR], 0.70; 95% confidence interval [CI], 0.33-1.48 and HR, 0.53; 95% CI, 0.26-1.07) and had nonsignificant effect on hazards of major bleeding (HR, 0.79; 95% CI, 0.38-1.64 and HR, 0.58; 95% CI, 0.26-1.27) versus warfarin. Rivaroxaban reduced the combined end point of ischemic stroke or ICH (HR, 0.45; 95% CI, 0.29-0.72) without an effect on major bleeding (HR, 1.07; 95% CI, 0.71-1.61). ICH occurred at rates of 0.16 to 0.61 events per 100 person-years in the 3 NOAC analyses, with no significant difference for any NOAC versus warfarin. Results from our study of the 3 NOACs versus warfarin in nonvalvular atrial fibrillation patients with a previous history of stroke/transient ischemic attack are relatively consistent with their respective phase III trials and previous stroke/transient ischemic attack subgroup analyses. All NOACs seemed no worse than warfarin in respect to ischemic stroke, ICH, or major bleeding risk.

Coleman CI ，Peacock WF ，Bunz TJ ，Alberts MJ ... -  《-》

Effectiveness and Safety of Dabigatran, Rivaroxaban, and Apixaban Versus Warfarin in Nonvalvular Atrial Fibrillation.

The introduction of non-vitamin K antagonist oral anticoagulants has been a major advance for stroke prevention in atrial fibrillation; however, outcomes achieved in clinical trials may not translate to routine practice. We aimed to evaluate the effectiveness and safety of dabigatran, rivaroxaban, and apixaban by comparing each agent with warfarin. Using a large US insurance database, we identified privately insured and Medicare Advantage patients with nonvalvular atrial fibrillation who were users of apixaban, dabigatran, rivaroxaban, or warfarin between October 1, 2010, and June 30, 2015. We created 3 matched cohorts using 1:1 propensity score matching: apixaban versus warfarin (n=15 390), dabigatran versus warfarin (n=28 614), and rivaroxaban versus warfarin (n=32 350). Using Cox proportional hazards regression, we found that for stroke or systemic embolism, apixaban was associated with lower risk (hazard ratio [HR] 0.67, 95% CI 0.46-0.98, P=0.04), but dabigatran and rivaroxaban were associated with a similar risk (dabigatran: HR 0.98, 95% CI 0.76-1.26, P=0.98; rivaroxaban: HR 0.93, 95% CI 0.72-1.19, P=0.56). For major bleeding, apixaban and dabigatran were associated with lower risk (apixaban: HR 0.45, 95% CI 0.34-0.59, P<0.001; dabigatran: HR 0.79, 95% CI 0.67-0.94, P<0.01), and rivaroxaban was associated with a similar risk (HR 1.04, 95% CI 0.90-1.20], P=0.60). All non-vitamin K antagonist oral anticoagulants were associated with a lower risk of intracranial bleeding. In patients with nonvalvular atrial fibrillation, apixaban was associated with lower risks of both stroke and major bleeding, dabigatran was associated with similar risk of stroke but lower risk of major bleeding, and rivaroxaban was associated with similar risks of both stroke and major bleeding in comparison to warfarin.

Yao X ，Abraham NS ，Sangaralingham LR ，Bellolio MF ，McBane RD ，Shah ND ，Noseworthy PA ... -  《Journal of the American Heart Association》

Comparison of the Effectiveness and Safety of Apixaban, Dabigatran, Rivaroxaban, and Warfarin in Newly Diagnosed Atrial Fibrillation.

No studies have performed direct pairwise comparisons of the effectiveness and safety of warfarin and the new oral anticoagulants (NOACs) apixaban, dabigatran, and rivaroxaban. Using 2013 to 2014 claims from a 5% random sample of Medicare beneficiaries, we identified patients newly diagnosed with atrial fibrillation who initiated apixaban, dabigatran, rivaroxaban, warfarin, or no oral anticoagulation therapy in 2013 to 2014. Outcomes included the composite of ischemic stroke, systemic embolism (SE) and death, any bleeding event, gastrointestinal bleeding, intracranial bleeding, and treatment persistence. We constructed Cox proportional hazard models to compare outcomes between each pair of treatment groups. The composite risk of ischemic stroke, SE, and death was lower for NOACs than for warfarin: hazard ratio (HR) 0.86, 95% confidence interval (CI) 0.76 to 0.98 for apixaban; 0.73, 95% CI 0.63 to 0.86 for dabigatran; and 0.82, 95% CI 0.75 to 0.89 for rivaroxaban, all compared with warfarin. There were no differences in effectiveness across NOACs. The risk of any bleeding was lower with apixaban than with warfarin, but higher with rivaroxaban than with warfarin. Apixaban (HR 0.69, 95% CI 0.60 to 0.79) and dabigatran (HR 0.79, 95% CI 0.69 to 0.92) were associated with lower bleeding risk than rivaroxaban. Treatment persistence was highest for apixaban (82%), and lowest for dabigatran and warfarin (64%) (p value <0.001). Compared with warfarin, NOACs are more effective in preventing stroke but their risk of bleeding varies, with rivaroxaban having higher risk than warfarin. Altogether, apixaban had the most favorable effectiveness, safety, and persistence profile.

Hernandez I ，Zhang Y ，Saba S 《-》

Efficacy and Safety of Apixaban, Dabigatran, Rivaroxaban, and Warfarin in Asians With Nonvalvular Atrial Fibrillation.

Whether non-vitamin K antagonist oral anticoagulants (NOACs) are superior to warfarin among Asians with nonvalvular atrial fibrillation remains unclear. In this nationwide retrospective cohort study collected from Taiwan National Health Insurance Research Database, there were 5843, 20 079, 27 777, and 19 375 nonvalvular atrial fibrillation patients taking apixaban, dabigatran, rivaroxaban and warfarin, respectively, from June 1, 2012 to December 31, 2016. Propensity-score weighting was used to balance covariates across study groups. Patients were followed until the first occurrence of any efficacy or safety outcome or the end date of study. Hazard ratios (95% confidence intervals) comparing apixaban, dabigatran, and rivaroxaban with warfarin were: ischemic stroke/systemic embolism (IS/SE), 0.55 (0.43-0.69), 0.82 (0.68-0.98), and 0.81 (0.67-0.97); major bleeding, 0.41 (0.31-0.53), 0.65 (0.53-0.80), and 0.58 (0.46-0.72); and all-cause mortality, 0.58 (0.51-0.66), 0.61 (0.54-0.68), and 0.57 (0.51-0.65). A total of 3623 (62%), 17 760 (88%), and 26 000 (94%) patients were taking low-dose apixaban (2.5 mg twice daily), dabigatran (110 mg twice daily), and rivaroxaban (10-15 mg once daily), respectively. Similar to all-dose NOACs, all low-dose NOACs had lower risk of IS/SE, major bleeding, and mortality when compared with warfarin. In contrast to other standard-dose NOACs, apixaban was associated with lower risks of IS/SE (0.45 [0.31-0.65]), major bleeding (0.29 [0.18-0.46]), and mortality (0.23 [0.17-0.31]) than warfarin. All NOACs were associated with lower risk of IS/SE, major bleeding, and mortality compared with warfarin in the largest real-world practice among Asians with nonvalvular atrial fibrillation. All low-dose NOACs had lower risk of IS/SE, major bleeding, and mortality when compared with warfarin. Standard-dose apixaban caused a lower risk of IS/SE, major bleeding, and mortality compared with warfarin.

Chan YH ，See LC ，Tu HT ，Yeh YH ，Chang SH ，Wu LS ，Lee HF ，Wang CL ，Kuo CF ，Kuo CT ... -  《Journal of the American Heart Association》