Comparing the Effectiveness and Safety of Nonvitamin K Antagonist Oral Anticoagulants and Warfarin in Elderly Asian Patients With Atrial Fibrillation: A Nationwide Cohort Study.

Stroke prevention in elderly patients with atrial fibrillation (AF) can be challenging, requiring a balance between thromboembolism prevention and serious bleeding. Comparisons of nonvitamin K antagonist oral anticoagulants (NOACs) and warfarin in older adults at different age strata (65-74, 75-89, and ≥ 90 years of age) in the daily practice have not been well described, particularly in Asians. We aimed to assess the clinical outcomes of NOACs compared with warfarin for stroke prevention in elderly patients with AF. From 2012 to 2015, 64,169 patients ≥ 65 years of age with AF who received at least one NOAC (dabigatran, rivaroxaban, or apixaban) or warfarin prescription were identified from the Taiwan National Health Insurance Research Database. The risks of ischemic stroke, intracranial hemorrhage (ICH), major bleeding, mortality, and composite adverse events were compared between NOACs and warfarin in all patients ≥ 65 years of age and, specifically, with different age strata (ie, 65-74, 75-89, ≥ 90 years). Overall, NOACs were associated with a significantly lower risk of ischemic stroke (adjusted hazard ratio [aHR], 0.869; 95% CI, 0.812-0.931), ICH (aHR, 0.524; 95% CI, 0.456-0.601), major bleeding (aHR, 0.824; 95% CI, 0.776-0.875), mortality (aHR, 0.511; 95% CI, 0.491-0.532), and composite adverse events (aHR, 0.646; 95% CI, 0.625-0.667) than warfarin. There was heterogeneity in treatment effect for NOACs vs warfarin in different age strata, but the results still favored NOACs even among very older adults (≥ 90 years). The results were generally consistent with propensity matching analysis. The absolute risk difference and reductions in ICH and composite adverse events with NOAC use were even greater among older adults than warfarin. Compared with warfarin, NOACs were associated with a significantly lower risk of adverse events, with heterogeneity in treatment effects among different age strata. Overall, the clear safety signal in favor of NOACs over warfarin was evident irrespective of age strata, being most marked in very older adults.

Chao TF ，Chiang CE ，Liao JN ，Chen TJ ，Lip GYH ，Chen SA ... -  《-》

Effectiveness and Safety of Standard-Dose Nonvitamin K Antagonist Oral Anticoagulants and Warfarin Among Patients With Atrial Fibrillation With a Single Stroke Risk Factor: A Nationwide Cohort Study.

Lip GYH ，Skjøth F ，Nielsen PB ，Kjældgaard JN ，Larsen TB ... -  《-》

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》

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 Non-Vitamin K Antagonist Oral Anticoagulant and Warfarin in Cirrhotic Patients With Nonvalvular Atrial Fibrillation.

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