Left Atrial Reverse Remodeling Following Valve Surgery for Chronic Degenerative Mitral Regurgitation in Patients with Preoperative Sinus Rhythm: Effects on Long-Term Outcome

BACKGROUND AND AIM OF STUDY: Chronic degenerative mitral regurgitation (MR) with left atrial (LA) enlargement is predictive of adverse cardiovascular events including stroke, atrial fibrillation (AF), and impaired survival. Mitral valve surgery (MVS) initiates left atrial reverse remodeling (LARR) characterized by LA volume reduction and improved function. The aim of this study was to evaluate the effects of LARR on clinical outcome in patients with and without LARR following MVS. METHODS: A retrospective study was conducted of 137 consecutive patients in sinus rhythm with degenerative severe MR undergoing isolated MVS. The left atrial volume index (LAVi) was assessed by studying pre- and postoperative echocardiograms; LARR was defined as a reduction in LAVi ≥ 15%. Clinical outcome was evaluated in relation to the absolute and relative reduction in LAVi, and the presence or absence of postoperative LARR. RESULTS: The incidence of postoperative LARR was 74% (n = 101). The overall 90-day survival was 100%. Freedom from complications and cardiac events 10 years after surgery for patients with LARR versus those without was: 92 ± 4% versus 66 ± 13% (p = 0.088) for mortality; 72 ± 1% versus 51 ± 18% (p = 0.131) for new onset of chronic AF; 72 ± 1% versus 81 ± 6% (p = 0.477) for cerebral thromboembolism; and 50 ± 10% versus 49 ± 11% (p = 0.744) for major cardiac adverse events. CONCLUSIONS: Preoperative LA enlargement due to severe degenerative MR in patients with sinus rhythm demonstrates a high potential for postoperative reverse remodeling following MVS. The absence of postoperative LARR was not associated with an increase in the risk of postoperative mortality or adverse clinical events.