Atrial Fibrillation and Coronary Artery Disease: Deciding on The Best Antithrombotic Regimen

Atrial fibrillation (AF) is a chronic progressive disease characterized by exacerbations and remissions. Up to 20–30% of patients with AF also have coronary artery disease (CAD). In patients with concomitant AF and CAD, the management of antithrombotic therapy is challenging. Oral anticoagulation (OAC) is indicated for the prevention of AF-related stroke and systemic embolism, whereas antiplatelet therapy is indicated for the prevention of coronary events. Each of these therapeutic avenues offers a relative efficacy benefit (e.g., dual antiplatelet therapy [DAPT] is more effective than OAC alone in reducing cardiovascular death, myocardial infarction, stent thrombosis, and ischemic coronary events in an ACS population), but with a relative compromise (e.g., DAPT is significantly inferior to OAC for the prevention of stroke/ systemic embolism in an AF population at increased risk of AF-related stroke). The purpose of this review is to explore the current evidence and rationale for antithrombotic treatment strategies in patients with both AF and CAD. A t r i a l F i b r i l l a t i o n S p e c i a l I s s u e Atrial fibrillation (AF) is the most common sustained arrhythmia, and represents a major burden to our healthcare system. Current evidence indicates that the prevalence of AF is in the range of 2% of the general population.1,2 Of those with AF, up to 20–30% have concomitant coronary artery disease (CAD), and 5–15% will require percutaneous coronary intervention (PCI).3,4 In patients with both AF and CAD the management of antithrombotic therapy can be challenging. Oral anticoagulation (OAC) is indicated for the prevention of AF-related stroke and systemic embolism, whereas antiplatelet therapy is indicated for the prevention of coronary events. Each offers a relative efficacy benefit with either a relative efficacy compromise or a relative safety compromise (e.g., dual antiplatelet therapy [DAPT] is more effective than OAC alone in reducing ischemic coronary events in an ACS population but is significantly inferior to OAC alone for the prevention of stroke/systemic embolism in an AF population).5 As such clinicians have perceived an obligation to treat patients with concomitant AF and CAD using both OAC with and antiplatelet therapy in spite of the potential for increased risk of fatal and nonfatal bleeding events, including intracranial hemorrhage.6–8 The purpose of this review is to explore the current evidence and rationale for antithrombotic treatment strategies in AF patients at risk for AF-associated stroke (i.e., those aged ≥ 65 years or CHADS2 score ≥ 1) with concomitant CAD. Specifically, with a focus on the key clinical questions of: (1) What is the