Efficacy and Safety of the Use of Non–Vitamin K Antagonist Oral Anticoagulants in Patients With Nonvalvular Atrial Fibrillation and Concomitant Aspirin Therapy

Abstract

Background: Current guidelines recommend non–vitamin K antagonist oral anticoagulants (NOACs) as the first-choice therapy in patients with nonvalvular atrial fibrillation because these drugs have several benefits over the vitamin K antagonists (VKAs). It is unknown whether these benefits remain when NOACs have to be combined with aspirin therapy. To assess the efficacy and safety of NOACs compared with VKAs in patients with atrial fibrillation and concomitant aspirin therapy, we conducted a systematic review and study–based meta-analysis of published randomized controlled trials. Methods: A systematic electronic literature search was done in MEDLINE, EMBASE, and Cochrane CENTRAL Register of Controlled Trials for studies including published data of patients ≥18 years of age with nonvalvular atrial fibrillation, randomized to either VKAs or NOACs, or receiving aspirin therapy at any time during the study that report all-cause stroke or systemic embolism, vascular death, myocardial infarction, major bleeding, or intracranial hemorrhage as an outcome. Hazard ratios (HRs) with 95% confidence intervals (CIs) for each outcome were extracted from the individual studies and pooled with random-effects meta-analysis. Results: This study-based meta-analysis was restricted to the subgroups of patients on aspirin therapy (n=21 722) from 4 randomized controlled trials comparing VKAs and NOACs (n=71 681) in nonvalvular atrial fibrillation. In this meta-analysis including patients on mainly low-dose aspirin, NOACs were found to be more effective (outcome of stroke or systemic embolism: HR, 0.78; 95% CI, 0.67–0.91; vascular death: HR, 0.85; 95% CI, 0.76–0.93) and as safe as VKAs with respect to major bleeding (HR, 0.83; 95% CI, 0.69–1.01). NOACs were safer with respect to the reduction of intracranial hemorrhage (HR, 0.38; 95% CI, 0.26–0.56). Conclusions: This study-based meta-analysis shows that it may be both safer and more effective to use NOACs compared with VKAs to treat patients with nonvalvular atrial fibrillation and concomitant aspirin therapy.