Search

Introduction: 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., Methods: 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., Results: 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)., Conclusion: 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., Competing Interests: Declarations. Conflict of Interest: Anandkumar Dubey, Amiee Kang, Jenny Jiang, and Dong Cheng are employees of BMS and may hold stock options. Nipun Atreja and Melissa Hagan were employees of BMS when the study was conducted. Nipun Atreja is currently affiliated with Immunovant. Melissa Hagan is currently affiliated with BeiGene. Abimbola Michael-Asalu is an employee of STATinMED. Steven Deitelzweig received research and consulting support from Pfizer and BMS. Ethical Approval: Since this study did not involve the collection, use, or transmittal of individually identifiable data, Institutional Review Board (IRB) approval was not required. This study only analyzed de-identified data which are a priori exempt from the Federal Policy for the Protection of Human Subjects (1991) and do not meet the identification criteria necessary to be privileged under the Health Insurance Portability and Accountability Act (HIPAA). Both the data and the security of the offices where the data were kept met HIPAA requirements. All authors had permission to access and use the database utilized in this study., (© 2025. The Author(s).)

Introduction: In the USA, there is a steady rise of atrial fibrillation due to the aging population with increased morbidity. This study evaluated the risk of stroke/systemic embolism (S/SE) and major bleeding (MB) among elderly patients with non-valvular atrial fibrillation (NVAF) and multimorbidity prescribed direct oral anticoagulants (DOACs)., Methods: Using the CMS Medicare database, a retrospective observational study of adult patients with NVAF and multimorbidity who initiated apixaban, dabigatran, or rivaroxaban from January 1, 2012 to December 31, 2017 was conducted. High multimorbidity was classified as having ≥ 6 comorbidities. Cox proportional hazard models were used to evaluate the hazard ratios of S/SE and MB among three 1:1 propensity score matched DOAC cohorts. All-cause healthcare costs were estimated using generalized linear models., Results: Overall 36% of the NVAF study population had high multimorbidity, forming three propensity score matched (PSM) cohorts: 12,511 apixaban-dabigatran, 60,287 apixaban-rivaroxaban, and 12,567 dabigatran-rivaroxaban patients. Apixaban was associated with a lower risk of stroke/SE and MB when compared with dabigatran and rivaroxaban. Dabigatran had a lower risk of stroke/SE and a similar risk of MB when compared with rivaroxaban. Compared to rivaroxaban, apixaban patients incurred lower all-cause healthcare costs, and dabigatran patients incurred similar all-cause healthcare costs. Compared to dabigatran, apixaban patients incurred similar all-cause healthcare costs., Conclusion: Patients with NVAF and ≥ 6 comorbid conditions had significantly different risks for stroke/SE and MB when comparing DOACs to DOACs, and different healthcare expenses. This study's results may be useful for evaluating the risk-benefit ratio of DOAC use in patients with NVAF and multimorbidity., (© 2022. The Author(s).)