Effectiveness and Safety in Patients with Non-Valvular Atrial Fibrillation Who Switched from Warfarin to Direct Oral Anticoagulants in Medicare Population.

Atrial fibrillation (AF), a common heart rhythm abnormality, is linked to a higher risk of stroke. Traditionally, warfarin has been the primary anticoagulation treatment for reducing the stroke risk. The new standard of treatment by direct oral anticoagulants (DOACs) offers greater benefits including improved efficacy and fewer adverse effects with reduced monitoring. This study aims to evaluate the risk of stroke/systemic embolism (SE) and major bleeding (MB) among patients with AF who switched from warfarin to DOACs. This study utilized Medicare data to conduct a retrospective analysis of patients with non-valvular atrial fibrillation (NVAF) who switched from warfarin to DOACs between January 1, 2012, and December 31, 2019. Patients with NVAF aged 65 and older who switched from warfarin and had continuous health plan enrollment were included. Descriptive statistics, propensity score matching (PSM), and Cox proportional hazard (PH) models were utilized to compare the outcomes and assess risks of SE and MB across the DOAC cohorts. Among 1,843,495 patients with NVAF on warfarin, 171,700 switched to DOACs within 90 days of discontinuation (apixaban: 90,850; rivaroxaban: 67,698; dabigatran: 12,900). The mean follow-up period across DOAC cohorts ranged from 552 to 628 days. After PSM, apixaban showed significantly lower rates of stroke/SE compared to dabigatran (2.99% vs. 3.98%, p < 0.0001) and rivaroxaban (3.08% vs. 3.80%, p < 0.0001). MB rates were also lower with apixaban versus dabigatran (4.29% vs. 5.57%, p < 0.0001) and rivaroxaban (4.07% vs. 6.35%, p < 0.0001). Cox PH models confirmed these findings, with apixaban demonstrating lower risks of stroke/SE [hazard ratio (HR) 0.83, 95% confidence interval (CI) 0.72-0.96 vs. dabigatran; HR 0.91, 95% CI 0.85-0.96 vs. rivaroxaban] and MB (HR 0.79, 95% CI 0.71-0.89 vs. dabigatran; HR 0.68, 95% CI 0.65-0.72 vs. rivaroxaban). The risk of stroke/SE and MB varies significantly among patients with NVAF switching from warfarin to different DOACs, with apixaban presenting the lowest risk compared to dabigatran and rivaroxaban.

Atreja N ，Dubey A ，Kang A ，Jiang J ，Hagan M ，Michael-Asalu A ，Cheng D ，Deitelzweig S ... -  《-》

Effectiveness and safety in non-valvular atrial fibrillation patients switching from warfarin to direct oral anticoagulants in US healthcare claims.

There is a paucity of real-world studies examining the risks of stroke/systemic embolism (SE) and major bleeding (MB) among non-valvular atrial fibrillation (NVAF) patients switching from warfarin to a direct oral anticoagulant (DOAC). This retrospective study was conducted to compare the stroke/SE and MB risks between patients switched from warfarin to apixaban, dabigatran, or rivaroxaban in real-world clinical practice. This study used data from four United States commercial claims databases from January 1, 2012 to June 30, 2019. The study population included NVAF patients initially treated with warfarin and switched to apixaban, dabigatran, or rivaroxaban within 90 days of their warfarin prescription ending. Patients were matched 1:1 between the DOACs in each database using propensity scores and then pooled for the final analysis. Cox proportional hazards models were used to calculate the risk of stroke/SE and MB. The final population consisted of 2,611 apixaban-dabigatran, 12,165 apixaban-rivaroxaban, and 2,672 dabigatran-rivaroxaban pairs. Apixaban vs. dabigatran was associated with a lower risk of stroke/SE (hazard ratio [HR]: 0.61; 95% confidence interval [CI]: 0.39-0.96) and MB (HR: 0.67; 95% CI: 0.50-0.91). Apixaban vs. rivaroxaban was associated with a similar risk of stroke/SE (HR: 0.88; 95% CI: 0.73-1.07) and a lower risk of MB (HR: 0.60; 95% CI: 0.52-0.68). There was no significant difference in either risk between dabigatran and rivaroxaban. These results provide important insights into how the risks of stroke/SE and MB for NVAF patients vary when switching from warfarin to different DOACs.

Lip GYH ，Noxon V ，Kang A ，Luo X ，Atreja N ，Han S ，Cheng D ，Jiang J ，Abramovitz L ，Deitelzweig S ... -  《-》

Comparative clinical outcomes between direct oral anticoagulants and warfarin among elderly patients with non-valvular atrial fibrillation in the CMS medicare population.

Amin A ，Keshishian A ，Dina O ，Dhamane A ，Nadkarni A ，Carda E ，Russ C ，Rosenblatt L ，Mardekian J ，Yuce H ，Baker CL ... -  《-》

Effectiveness and safety of direct oral anticoagulants compared to warfarin in treatment naïve non-valvular atrial fibrillation patients in the US Department of defense population.

Gupta K ，Trocio J ，Keshishian A ，Zhang Q ，Dina O ，Mardekian J ，Nadkarni A ，Shank TC ... -  《BMC Cardiovascular Disorders》

Direct Oral Anticoagulants Compared With Warfarin in Patients With Atrial Fibrillation and Valvular Heart Disease Without Mechanical Valves.

Dawwas GK ，Lewis JD ，Cuker A 《Journal of the American Heart Association》