Safety and efficacy of apixaban for the prevention of thromboembolism in adults with congenital heart disease and atrial arrhythmias: a prospective cohort study with historical control comparison

Abstract

Abstract Introduction In adults with congenital heart disease (ACHD), atrial arrhythmias (AA) confer an increased risk of thromboembolic events. Data regarding treatment with non-vitamin K oral anticoagulants (NOACs) of patients with ACHD and AA are limited. Methods A prospective, multicenter, observational study of ACHD patients with AA (atrial fibrillation, atrial flutter, or intra-atrial re-entrant tachycardia) treated with apixaban from 2019 to 2022 was performed (PROTECT-AR, NCT03854149). Comparisons were made with a historical vitamin-K antagonist (VKA) treatment cohort from 2002 to 2014. The primary efficacy endpoint was the composite of stroke or thromboembolism. The primary safety endpoint was major bleeding. Results The apixaban-treated cohort consisted of 215 patients (median follow-up 28 months) and the historical VKA-treated ­cohort consisted of 229 patients with ACHD and AA (median follow-up 48 months). The burden of age and comorbidities was higher in the apixaban versus the VKA treatment group (Table). Comparing the apixaban with the VKA treatment group yielded no significant differences in the annualized rate of stroke or thromboembolism (1.2% vs. 1.4%, respectively; p=0.24) and major bleeding (1.2% vs. 4.4%, respectively; p=0.08) (Figure). Conclusion In ACHD patients with AA treated with apixaban as part of routine care, the risk of major thromboembolic and bleeding events was low. This risk was comparable with historical cohort data on VKA. Prospective studies directly comparing NOAC and VKA-treated patients are needed.