Author + information
- Greg C. Flaker,
- Stefan Hohnloser,
- Daniel Wojdyla,
- Elaine Hylek,
- David Garcia,
- Renee Sullivan,
- Renato Lopes,
- Sana M. Al-Khatib and
- Christopher Granger
Compared with warfarin, apixaban has been shown to reduce stroke, systemic embolism, mortality and major bleeding. Amiodarone may lead to poor INR control and excess embolic and bleeding events when used with warfarin. Interactions between apixaban and amiodarone on clinical outcomes have not been explored.
The Apixaban for Reduction In Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial included 18,201 patients randomized to apixaban 5mg twice daily or warfarin (target INR 2-3). This analysis explores outcomes in patients on and off amiodarone. Endpoints were summarized using rates/100 patient years of follow-up. The Cox regression model was used to derive hazard ratios comparing apixaban vs. warfarin and test the interaction between randomized treatment and amiodarone.
From the overall population, 2,051 (11%) patients received amiodarone at randomization including 1,009 patients assigned to apixaban and 1,042 assigned to warfarin. Patients on amiodarone were younger (median 68 vs. 70 years) and had lower CHADS2 score (mean 2.0 vs. 2.1). Patients assigned to warfarin who were on amiodarone had a lower mean time in therapeutic range (TTR) when compared with those who were not on amiodarone (56.5% vs. 63%, p < 0.0001). Outcomes are shown in the table.
Despite a lower TTR with warfarin and amiodarone, the efficacy and safety of apixaban versus warfarin is consistent in patients with or without concomitant amiodarone therapy.
Oral Contributions West, Room 3009
Sunday, March 10, 2013, 8:45 a.m.-9:00 a.m.
Session Title: Joint Session of the Heart Rhythm Society and the American College of Cardiology: Anticoagulation in Atrial Fibrillation -Management Questions with New Anticoagulants
Abstract Category: 4. Arrhythmias: AF/SVT
Presentation Number: 914-6
- 2013 American College of Cardiology Foundation