Antithrombotic therapy for chronic coronary syndrome and atrial fibrillation: less might be more

The best strategy in atrial fibrillation (AF) after > 12 months after an acute coronary syndrome or in patients with chronic coronary syndrome without an indication for interventional revascularization remains unclear. European guidelines generally recommend therapy with oral anticoagulation (OAC) alone, whereas North American guidelines advise combination therapy consisting of OAC plus antiplatelet therapy in some patients. We performed a meta-analysis of available trials comparing these treatment strategies. The primary endpoint was major adverse cardiac events (MACE), secondary endpoints included major bleeding, ischemic and hemorrhagic stroke, myocardial infarction (MI), all-cause mortality, and cardiovascular mortality. Study level data were analyzed. Heterogeneity was assessed using the I² statistic. risk rates (RR) were calculated using a random-effects model (DerSimonian and Laird). Two randomized trials evaluating 1905 patients were included in this meta-analysis. Rates of MACE (RR 0.91 95% CI 0.58-1.41; p = 0.66; I² 75%), MI (RR 1.75 95% CI 0.87-3.55; p = 0.12; I² 0%) and ischemic stroke (RR 0.83 95% CI 0.53-1.31; p = 0.42; I² 0%) did not differ between the OAC monotherapy and the OAC combination therapy. With regards to safety, rates of major bleeding (RR 0.66 95% CI 0.49-0.91; p = 0.01; I² 0%), and of hemorrhagic stroke (RR 0.43 95% CI 0.19-1.00; p = 0.05; I² 0%) were lower in patients on OAC monotherapy. Based on available evidence summarized in this meta-analysis, we think that primum non nocere still stands true: unless future randomized evidence suggests otherwise, most AF patients should be on OAC monotherapy.