The necessity to add two antiplatelet agents to an oral anticoagulant (OAC) often arises in patients with atrial fibrillation (AF) in routine clinical practice. The majority of AF patients have an indication for continuous OAC, and coronary artery disease co-exists in 25% of these patients. The increasing use of drug-eluting stents to minimize intrastent restenosis necessitates long-term dual antiplatelet therapy with Aspirin plus Clopidogrel to reduce the risk of early and late stent thrombosis. Combined aspirin–clopidogrel therapy, however, is less effective in preventing stroke compared with OAC alone in AF patients, and OAC alone is insufficient to prevent stent thrombosis. The management of AF patients presenting with an acute coronary syndrome poses similar management complexities. Since AF and coronary artery disease with stent placement are common, it is relatively frequent to treat patients with both these conditions, where triple antithrombotic therapy with Aspirin, Clopidogrel and an OAC would be needed. Dabigatran etexilate, an oral direct thrombin inhibitor, has shown that compared with Warfarin given at a dose of 150 mg twice daily significantly reduces stroke with less intracranial bleeding, and at a dose of 110 mg twice daily has similar efficacy with less bleeding. Although, Dabigatran maintained its overall favorable profile compared with Warfarin in patients on dual antiplatelet therapy, we should always bear in mind for the sake of our AF patients that combining dual antiplatelet therapy with chronic anticoagulation with Dabigatran, as well as with Warfarin, significantly increases bleeding risk. This triple therapy association should be evaluated in the individual patient after carefully balancing bleeding versus thrombotic risk.
Credits: Osmar Antonio Centurión, MD, PhD, FACC