Boston—Triple antithrombotic therapy consisting of warfarin plus two antiplatelet agents currently is the standard of care after percutaneous coronary intervention (PCI) for patients with atrial fibrillation. The problem, according to a new study, is that a high risk of bleeding accompanies the therapy.

The report, presented at the European Society of Cardiology meeting in Barcelona, Spain, and concurrently published in the New England Journal of Medicine, offers evidence that using only two anticlotting medicines is safer for patients who have atrial fibrillation and have had a stent placed in a heart artery.

The RE-DUAL PCI trial, sponsored by Boehringer Ingelheim, found that using the anticoagulant dabigatran along with a second anticlotting drug—either clopidogrel or ticagrelor—appears to lessen the risk of major or clinically relevant nonmajor bleeding compared to using warfarin with aspirin as well as either clopidogrel or ticagrelor.

To reach their conclusion, researchers tested dabigatran at two dosage strengths, determining that the risk of bleeding was halved in patients who received the 110-mg dose and reduced by one-quarter in those who received the 150-mg dose of dabigatran, compared with warfarin. At the same time, the study team detected no increase in cardiac events related to clotting.

“When we treat patients who have atrial fibrillation and need a stent, we need to strike a difficult balance between risk of clotting and risk of bleeding,” explained cardiologist Christopher Cannon, MD, of Brigham and Women’s Hospital, who presented the research. “Our study finds that patients who received two anticlotting medications— including one of a newer class of drug—had fewer bleeding events without being more at risk for a stroke or other cardiac events.”

The trial was designed and led by an executive steering committee and the sponsor, Boehringer Ingeheim, the manufacturer of dabigatran, in collaboration with an international steering committee. Included were 2,725 patients with atrial fibrillation who had undergone stenting.

Results indicate that about 26.9% of patients on warfarin triple therapy experienced bleeding, compared with 15.4% of patients on double therapy with the 110-mg dose of dabigatran. With the 150-mg dabigatran dose, about 20.2% of patients on double therapy experienced bleeding compared with 25.7% of the corresponding warfarin triple-therapy cohort.

Background information in the study notes that other recent studies have also suggested that dropping aspirin from triple therapy could help decrease bleeding events and that the view receives strong support from RE-DUAL.

“These data are very reassuring,” said Cannon. “We now have new information to help select the right treatment for individual patients—which has been hard to date, and this study can help.”

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