Outcome of mitral repair combined with Cox-maze procedure for atrial functional mitral regurgitation with heart failure with recovered ejection fraction

OBJECTIVES: Atrial functional mitral regurgitation (AFMR) in patients with heart failure with recovered ejection fraction has received insufficient attention. This study analysed the prognosis and outcomes of mitral valve (MV) repair combined with the Cox-maze procedure. METHODS: A prospective cohort study of patients with AFMR with left ventricular ejection fraction (LVEF) <40% was conducted. All patients received guideline-directed medical therapy. Those with recovered ejection fraction underwent MV repair combined with the Cox-maze procedure. Mortality, atrial fibrillation (AF) recurrence, mitral regurgitation (MR) and postoperative tricuspid regurgitation were assessed using the inverse probability weighting (IPW) method. RESULTS: In total, 312 patients were enrolled in this study between 2010 and 2019, 247 of whom underwent MV repair combined with the Cox-maze procedure [full recovery (LVEF > 50%): n = 132, partial recovery (LVEF of 40-50%): n = 115]. IPW-adjusted survival of patients with LVEF ≥50% and LVEF 40-50% showed no significant difference [hazard ratio (HR): 2.18, 95% confidence interval: 0.46-10.38, P = 0.33]. However, patients with LVEF ≥50% had better IPW-adjusted long-term freedom from recurrent MR [HR: 2.44 (1.28-4.63), P = 0.0065] and AF recurrence [HR: 1.85 (1.06-3.21), P = 0.030] than those with LVEF of 40-50%. CONCLUSIONS: MV repair combined with the Cox-maze procedure was effective and feasible in patients with severe AFMR with heart failure with recovered ejection fraction. Additionally, patients with LVEF ≥50% after guideline-directed medical therapy undergoing these combined procedures had better long-term freedom from recurrent AF and MR than those with LVEF of 40-50%.