Mitral Valve Disease and Outcomes Following Acute Cardioversion for Atrial Fibrillation

Risks and management for acute electrical cardioversion (CV) for atrial fibrillation (AF) reversal in general populations are well-cited; the outcomes for patients with coexisting mitral valve disease remain poorly understood. The known atrial hemodynamic alteration-based risks associated with mitral valve insufficiency (MVI) and mitral valve stenosis (MVS) lack data on outcomes following CV. The aim of this study is to evaluate whether preexisting mitral valve pathology influences the outcomes of stroke and mortality following CV to guide subpopulation risk-mitigation.

A retrospective cohort study using TriNetX data on AF patients undergoing acute electric CV (index event) was conducted, stratified by MVI or MVS status. MVI and MVS cohorts were propensity-matched to the control group of patients without mitral valve pathology. Outcomes included mortality and ischemic stroke (I63) at 30 days and 1 year. Relative risks (RR) with 95% confidence intervals (CIs) and p-values were calculated for this data.

Following TriNetX data analysis, within the mitral valve stenosis cohort, stroke risk was similar at 30 days but was significantly higher at 1 year compared with controls (7.2% vs 4.9%, RR 1.47 (95% CI 1.12-1.91), p = 0.005), with no differences in mortality. Comparatively, the mitral valve insufficiency cohort demonstrated a more modest 1-year increase in stroke risk (5.1% vs 4.2%; RR 1.21 (95% CI 1.17-1.27), p < 0.001) and a significant reduction in 1-year mortality (RR 0.80 (95% CI 0.77-0.82), p < 0.001).

MVS was associated with a significantly elevated stroke risk following acute CV for AF at 1 year and associated with an increased risk of mortality. Surprisingly, mortality risk was reduced for MVI, despite their modestly elevated 1-year stroke risk. These findings highlight that subpopulations with mitral valve disease have different risk profiles. Despite propensity matching in this retrospective analysis, residual confoundings cannot be excluded; further investigation is needed.