Comparison of outcomes of direct-acting oral anticoagulants vs. vitamin K antagonists in patients with bioprosthetic heart valves or valve repair: a systematic review and meta-analysis.

OBJECTIVE

To compare the outcomes between direct-acting oral anticoagulants and vitamin K antagonists, particularly for risk of stroke and bleeding, among patients with atrial fibrillation (AF) and bioprosthetic heart valve replacement or repair.

MATERIALS AND METHODS

A systematic search was conducted in the PubMed, Scopus, Cochrane Database of Systematic Reviews and Google scholar databases. Studies that were done in patients with AF who underwent bioprosthetic heart valve replacement or repair and that compared the outcomes between the use of direct-acting oral anticoagulants (DOACs) and vitamin K antagonists were eligible for inclusion. Studies that were preferably randomized controlled trials or adopted a cohort approach or retrospective data-based studies were considered for inclusion. The strength of association was presented in the form of pooled hazards risk (HR). Statistical analysis was done using STATA version 16.0.

RESULTS

A total of 8 articles were included in the meta-analysis. There were no significant differences in the risk of "all-cause stroke" [HR 0.72, 95% CI: 0.39, 1.34] and ischemic stroke [HR 0.79, 95% CI: 0.49, 1.29] between the two groups. The risk of "any bleeding" [HR 0.74, 95% CI: 0.64, 0.87], major bleeding [HR 0.60, 95% CI: 0.42, 0.86] and intra-cranial bleeding [HR 0.54, 95% CI: 0.36, 0.81] was much lower in those that received DOAC compared to warfarin. Compared to those receiving warfarin, those on DOACs had substantially reduced risk of any clinical thromboembolic events [HR 0.52, 95% CI: 0.39, 0.70]. No significant differences were noted for all-cause mortality [HR 0.88, 95% CI: 0.74, 1.05], cardiovascular events/myocardial infarction (MI) [HR 0.58, 95% CI: 0.33, 1.04] and and readmission rates [HR 0.85, 95% CI: 0.62, 1.18].

CONCLUSIONS

Findings suggest that the use DOACs in patients with AF with bioprosthetic valve replacement or repair is comparatively better than vitamin K antagonists in reducing the risk of bleeding and thrombo-embolic events. Future studies with a randomized design and larger sample sizes are needed to further substantiate these findings.