Effect of concomitant antiplatelet therapy in patients with nonvalvular atrial fibrillation initiating non-vitamin K antagonists

Background Antiplatelet therapy (APT) use in combination with oral anticoagulation is common among patients with atrial fibrillation, but there is scarce information regarding its effect on outcomes in patients on non-vitamin K antagonist oral anticoagulants (NOAC). We aimed to evaluate the safety and efficacy of APT use in a 'real-world' cohort of nonvalvular atrial fibrillation (NVAF) patients initiating NOAC. Design We conducted a retrospective multicentre study including 2361 consecutive NVAF patients initiating NOAC between January 2013 and December 2016. Patients with an acute ischaemic event within the last 12 months (acute coronary syndrome, stroke or revascularization) were excluded. Patients were followed up, and all clinical events were recorded at 3 months. The primary outcome of the study was major bleeding, and the secondary outcomes were stroke, nonfatal myocardial infarction, intracranial bleeding and death. Results One hundred forty-five (6.1%) patients received concomitant APT, and aspirin was the more common (79%). At 3 months, 25 (1.1%) patients had major bleeding, 8 (0.3%) had nonfatal myocardial infarction, 7 (0.3%) had ischaemic stroke, and 40 (1.7%) died. After multivariate adjustment, concomitant APT was associated with higher risk for major bleeding (HR = 3.62, 95% CI 1.32-9.89; P = .012), but was not associated with a higher risk of other clinical outcomes. Conclusions Concomitant APT use is uncommon among these patients and does not seem to be associated with lower rates of ischaemic events or death. However, there are signals for an increased risk of bleeding, which reinforces current guideline recommendations.