# Postoperative Anticoagulation After Mitral Bioprosthetic Valve Surgery: A Systematic Review and Meta-Analysis of Non-vitamin K Antagonist Oral Anticoagulants Versus Warfarin

## TL;DR

This study compares the safety and effectiveness of NOACs and warfarin for anticoagulation after mitral valve surgery, finding similar outcomes but calling for more research.

## Contribution

A systematic review and meta-analysis comparing NOACs to warfarin specifically after mitral bioprosthetic valve surgery.

## Key findings

- NOACs showed similar or lower rates of stroke, bleeding, and mortality compared to warfarin.
- Current evidence is limited by study heterogeneity and wide confidence intervals.
- Valve thrombosis and rehospitalization rates were comparable but infrequently reported.

## Abstract

The optimal anticoagulation strategy following mitral bioprosthetic valve replacement (BPVR) remains unclear. This meta-analysis evaluates the safety and efficacy of non-vitamin K antagonist oral anticoagulants (NOACs) compared to warfarin in this context. We systematically searched PubMed, Embase, Cochrane, and other databases for studies published between 2015 and 2025, comparing NOACs to warfarin in adults with mitral bioprostheses. Eligible studies reported thromboembolic and/or bleeding outcomes, with a minimum of six months' follow-up. Random-effects meta-analysis was performed, calculating odds ratios (ORs) with 95% confidence intervals (CIs). Heterogeneity was assessed using the I² statistic, and publication bias was assessed via funnel plot and Egger’s test. Eight studies met the inclusion criteria, comprising 1,506 patients (709 on NOACs and 797 on warfarin). Included studies were randomized controlled trials (RCTs) and observational cohorts. NOACs studied were apixaban, rivaroxaban, and dabigatran. Three studies were included in the quantitative synthesis for each primary outcome. For stroke/systemic embolism, the pooled OR for NOACs was 0.57 (95% CI: 0.02-16.87, p = 0.55; I² = 33.7%). For major bleeding, the pooled OR was 1.06 (95% CI: 0.12-9.47, p = 0.94; I² = 74.9%). No significant publication bias was detected. Qualitative findings suggested NOACs had similar or lower rates of stroke, major and minor bleeding, and all-cause mortality. Valve thrombosis and rehospitalization were infrequently reported and comparable. NOACs appear to be a safe and effective alternative to warfarin after mitral BPVR. However, current evidence is limited by heterogeneity and wide CIs. Further large-scale RCTs are needed to confirm these findings.