Concomitant use of direct oral anticoagulants and aspirin versus direct oral anticoagulants alone in atrial fibrillation and flutter
Journal of the American College of Cardiology
Background About 3% of adults in the USA have atrial fibrillation (AF), which is associated with approximately two-fold increased mortality. We hypothesize that the concurrent use of Direct Oral Anticoagulants (DOACs) and aspirin in AF and AFL will result in less major adverse cardiac events (MACE) compared to DOACs alone.
Methods This is an observational retrospective study that included adults with nonvalvular AF and AFL on any DOAC. The cohort was obtained by querying the electronic health record at Beaumont Health between 2010 and 2015 and was classified into two groups based on the presence or absence of concurrent aspirin use. Patients who had another indication for anticoagulation therapy, and those on other antiplatelet agents were excluded. The primary outcome was MACE which included ischemic stroke, systemic embolism, and acute coronary syndrome. Secondary outcomes were any bleeding that lead to a hospital visit, and death. A minimum of two-year period was allowed to observe the outcomes. Propensity scores were calculated for baseline characteristics and used to achieve balance between the two groups. Hazard ratios and 95% confidence intervals (CI) were calculated for outcomes using a Cox proportional hazard model.
Results 9,136 patients with AF or AFL on a DOAC were identified. After applying the exclusion criteria, 7,455 patients were classified into the DOAC group (3,817) and DOAC with aspirin group (3,638). 3,368 subjects from the DOAC group and 2,866 from the combination therapy group either did not have events or were in the other group at the time of the first event, which left 449 subjects on DOAC only and 772 on the combination therapy for analysis. Adjusted analysis revealed that MACE occurred more in the combination group (Hazard ratio of 2.12, 95% CI [1.85-2.43]). Bleeding also occurred more in the combination group (Hazard ratio 1.31, 95% CI [1.17-1.46]).
Conclusion The concomitant use of DOAC and aspirin in patients with AF or AFL resulted in more MACE as well as more bleeding when compared to DOAC therapy alone. This concurs with a meta-analysis in 2016 showing that a combination of anticoagulation and antiplatelet therapy did not decrease MACE and caused more bleeding.
9 Supplement 1
Said A, Keeney S, Halalau A. CONCOMITANT USE OF DIRECT ORAL ANTICOAGULANTS AND ASPIRIN FOR CARDIOVASCULAR DISEASE PREVENTION IN ATRIAL FIBRILLATION AND FLUTTER. Journal of the American College of Cardiology. 2019 Mar 12;73(9S1):321-.