Cardioversion in the RE-LY Trial

About 2.3 million Americans are currently living with atrial fibrillation (AF), and the prevalence is expected to increase to 5.6 million by 2050. AF increases the risk of stroke nearly five-fold and is associated with up to 15% of all strokes in the United States. It imposes a substantial economic burden to the healthcare system, specifically because of stroke management and hospitalizations costs. Recently, the FDA approved dabigatran (Pradaxa, Boehringer Ingelheim Pharmaceuticals, Inc.), an oral anticoagulant indicated to reduce the risk of stroke for patients with AF. The approval was based on findings from the Randomized Evaluation of Long-Term Anticoagulant Therapy (RE-LY) trial, which showed that 110 mg dabigatran was associated with rates of stroke and systemic embolism that were similar to those associated with warfarin, as well as lower rates of major hemorrhage. Dabigatran 150 mg was associated with lower rates of stroke and systemic embolism than warfarin, with similar rates of major hemorrhage. An Important Sub-Analysis Currently, guidelines recommend using anticoagulation for at least 3 weeks prior and 4 weeks after cardioversion to reduce the risk of associated thromboembolisms, but this recommendation is based on limited data. In the January 18, 2011 issue of Circulation, my colleagues and I had a study published from a post-hoc analysis of the RE-LY trial among patients with non-valvular atrial fibrillation (NVAF) undergoing cardioversion, a treatment designed to convert abnormal heartbeat back to normal sinus rhythm. According to recent estimates, NVAF represents approximately 95% of all AF cases in the United States. Cardioversion is one treatment option for patients with AF and requires anticoagulation both prior to and following treatment in...