Left ventricular ejection fraction decline shortly after mitral valve operation and associated survival

Objective Reduction in left ventricular ejection fraction (LVEF) is common after mitral valve (MV) repair or replacement in patients with mitral regurgitation (MR). This study aims to evaluate the trajectory of postoperative LVEF reduction after MV surgery and determine if this change in LVEF is associated with clinical outcomes. Methods This is a retrospective study of 625 patients who underwent MV surgery for moderate/severe mitral valve regurgitation between 2015 and 2023. Patients with aortic valve pathology, concomitant aortic procedures, endocarditis, and prior MV operations were excluded. Patients were divided into four quartiles based on pre and post-operative percent difference in LVEF. In-hospital outcomes and long-term mortality using Kaplan-Meier (KM) analysis were compared between groups. Cubic spline adjusted for preoperative LVEF was used to determine the impact of percent LVEF difference on mortality. Spaghetti plots depicted the trajectory in LVEF over a 2-year follow up period. Results Patients were divided into percent LVEF reduction quartiles as follows: severely reduced (159 (25.4%), greater than -19%), moderately reduced (157 (25.1%), between -19% and -7%), stable (171 (27.4%), between -8% and +4%), and increased (138 (22.1%), greater than a +4%). Baseline characteristics were similar. There was no difference in the percent of patients undergoing MV repair versus replacement across LVEF reduction groups (p=0.55). Postoperative outcomes were similar between groups, including reoperation for bleeding, stroke, and atrial fibrillation. Long-term survival probability over 7 years was similar between all four groups (p=0.35). There was no significant change in hazards ratio for long-term mortality across range of LVEF differences. Patients with severely or moderately reduced LVEF postoperatively remained with a depressed LVEF during the 2-year follow-up period, while patients with the same or increased postoperative LVEF returned to baseline. Conclusions Reduction in LVEF is common after MV repair or replacement with effects persisting after two years. Changes in LVEF after MV operation do not appear to affect clinical outcomes and may by itself not accurately reflect myocardial dysfunction related to MR and subsequent intervention.