Analysis of RE-LY Trial Shows Favorable Results for Dabigatran

Rates of stroke, embolism, and bleeding in atrial fibrillation patients undergoing cardioversion who received dabigatran are similar to those treated with warfarin.

As previously mentioned in this article on key findings in cardiovascular research in 2010, several studies last year “showed positive results for warfarin alternatives, including the Randomized Evaluation of Long-term anticoagulant therapy (RE-LY) trial, which outlined the benefits of dabigatran in reducing stroke and bleeding in atrial fibrillation (AF) patients.”

Now, analysis of results of a study among patients with non-valvular atrial fibrillation (NVAF) undergoing cardioversion (outcomes measures for which included stroke, systemic embolism, and major bleeding episodes within 30 days of the cardioversion) show that rates of stroke and systemic embolism and major bleeding were low and comparable to warfarin in cardioverted patients receiving Pradaxa (dabigatran etexilate mesylate) 150mg capsules.

The article based on this study, “Dabigatran vs. Warfarin in Patients with Atrial Fibrillation: An Analysis of Patients Undergoing Cardioversion,” was published ahead of print on the Circulation website. In it, the authors describe this study as “the largest cardioversion experience to date and the first to evaluate a novel anticoagulant in this setting.” They concluded that “the frequencies of stroke and major bleeding within 30 days of cardioversion on the 2 doses of dabigatran [dabigatran 110 mg BID and 150 mg BID] were low and comparable to those on warfarin with or without transesophageal echocardiography guidance. Dabigatran is a reasonable alternative to warfarin in patients requiring cardioversion.”

In a news release from Boehringer Ingelheim, study author Rangadham Nagarakanti, MD, Louisiana State University School of Medicine, said “Cardioversion is one treatment option for patients with atrial fibrillation and requires anticoagulation both prior to and following treatment in order to reduce the risk of stroke… It’s helpful to know that patients on Pradaxa who underwent cardioversion had low rates of stroke and systemic embolism and bleeding similar to warfarin.”

The news release notes that in the RE-LY trial, an imaging technique known as transesophageal echocardiography (TEE) “was encouraged prior to cardioversion to identify existing clots in the left atrium of the heart, which would suggest an increased risk of stroke or embolism associated with cardioversion.” It also reports that TEE was performed prior to cardioversion in more patients on dabigatran 110mg and 150mg than warfarin, and that rates of stroke and systemic embolism were similar across all treatment arms for those who underwent TEE-guided cardioversions and those who did not undergo TEE. Specifically, rates of stroke and systemic embolism within 30 days of cardioversion “were low and did not differ significantly between treatment arms (0.77%, 0.3% and 0.6%, respectively; dabigatran 110mg vs. warfarin, p=0.71; PRADAXA 150mg vs. warfarin, p=0.45).”

Additional Resources:

Dabigatran vs. Warfarin in Patients with Atrial Fibrillation (NEJM, September 2009)

RE-LY Substudy Finds DAbigatran Effective in Secondary Stroke Prevention

Randomized Evaluation of Long Term Anticoagulant Therapy (RE-LY) with Dabigatran Etexilate