BACKGROUND: Patients with adult congenital heart disease (CHD) have various indications for anticoagulation (e.g., presence of Fontan circuit, atrial fibrillation due to surgical scar). Guidelines recommend vitamin K antagonists (VKA) for thromboprophylaxis in adult CHD, as trial data comparing safety/efficacy of direct oral anticoagulants (DOAC) to VKA are not available in this population.

METHODS: PubMed/MEDLINE, Embase, Web of Science, and Google Scholar were searched for trials comparing DOAC with VKA in patients with ACHD. Outcomes of interest were efficacy endpoints (thromboembolic complications) and safety endpoints (bleeding complications). Results were meta-analyzed and sensitivity analyses were performed.

RESULTS: A total of 4 retrospective studies comprising 6004 patients (2566 DOAC, 3438 VKA) were analyzed. Compared with VKA, DOAC did not cause a statistically significant difference in incidence of thromboembolism (risk ratio, RR, 0.76; 95% confidence intervals, CI, 0.28, 2.07); composite bleeding (RR 1.02, 95% CI 0.71, 1.47); major bleeding (RR 1.05, 95% CI 0.92, 1.21); minor bleeding (RR 1.12, 95% CI 0.51, 2.44); or intracranial bleeding (RR 0.86, 95% CI 0.50, 1.46). Numerically, the DOAC arm had fewer thromboembolisms/intracranial bleeds but more major/composite bleeds. However, upon removal of the largest study, the DOAC arm had fewer major/composite bleeds.

CONCLUSIONS: DOAC did not confer a significant increase in either thromboembolic or bleeding risk as compared with VKA. Sensitivity analysis showed notable heterogeneity among studies. Large-scale trials comparing DOAC with VKA in patients with adult CHD are needed.