It can be difficult to balance the prevention of thrombosis with the risk of bleeding when determining the best approach for antithrombotic therapy in patients with atrial fibrillation undergoing percutaneous coronary intervention (PCI).
Until recently, most guidelines recommended both anticoagulation and dual antiplatelet therapy (triple therapy) for these patients. However, studies have shown that these regimens are associated with high rates of major bleeding, which has led clinicians and others to look at new therapeutic strategies, according to the authors of a major new study.
The study, published in The New England Journal of Medicine, compared the use of two dosage levels of dabigatran etexilate (Pradaxa), a non–vitamin K antagonist oral anticoagulant (NOAC), in dual therapy to a triple therapy using warfarin to reduce the risk of bleeding. The difference in risk between the 110-mg dual-therapy group and the triple-therapy group was 48%, while the difference in risk between the 150-mg dual-therapy group and the triple-therapy group was 28% during the period of treatment, the researchers found.
Christopher P. Cannon, MD, cardiologist at Brigham and Women’s Hospital, and his colleagues conducted the Randomized Evaluation of Dual Antithrombotic Therapy with Dabigatran versus Triple Therapy with Warfarin in Patients with Nonvalvular Atrial Fibrillation Undergoing Percutaneous Coronary Intervention (RE-DUAL PCI) trial study. They compared dual therapy with triple therapy after percutaneous coronary intervention (PCI) with stent placement in more than 2,700 adults who had atrial fibrillation. Patients were either treated with warfarin (Coumadin and other brand names), a P2Y12 inhibitor and aspirin, or with 110 mg or 150 mg twice daily dabigatran etexilate (Pradaxa), a P2Y12 inhibitor, but no aspirin. The first group was the triple therapy group and the second group was the dual therapy group. The study was supported by Boehringer Ingelheim, the maker of Pradaxa.
“The dabigatran doses investigated in this trial are the same doses which have already demonstrated effective stroke prevention in atrial fibrillation and are therefore approved around the world in this indication,” Boehringer Ingelheim said in a statement.
They found that, among patients with atrial fibrillation who had undergone PCI, dual therapy with dabigatran and a P2Y12 inhibitor resulted in a risk of bleeding events that was significantly lower than the risk with triple therapy with warfarin, a P2Y12 inhibitor, and aspirin.
“Rates of … major bleeding were significantly lower in both dual-therapy groups than in the triple-therapy group, findings that reaffirmed the safety of dabigatran in these regimens, even at a dose of 150 mg,” the researchers noted.
“In the dual-therapy regimens, each of the two doses of dabigatran led to a balance between the risk of bleeding and the prevention of thromboembolic events, which offers clinicians two additional options for the treatment of patients with varying risks of thromboembolic events and bleeding,” they added.