Determinants of Left Atrial Reverse Remodeling after Valve Surgery for Degenerative Mitral Regurgitation

Background and aim of the study: Left atrial (LA) enlargement is a pathophysiological response to volume overload resulting from chronic mitral regurgitation (MR), is known as LA remodeling, and has been shown previously to be associated with cardioembolic events. Following mitral valve surgery (MVS), the left atrium may undergo reverse remodeling characterized by LA volume reduction. The study aim was to evaluate the incidence and determinants of postoperative left atrial reverse remodeling (LARR) following MVS. Methods: The postoperative left atrial volume index (LAVi) was determined echocardiographically in patients with degenerative chronic MR undergoing isolated MVS (n = 110), using three different algorithms, and compared to the preoperative values. LARR was defined as a reduction in LAVi ≥15%. Results: The postoperative mean LA diameter (p <0.001), LA area (p <0.001),

and LAVi (p <0.001) were each decreased significantly. LARR was observed in 84 patients (76%), with a mean postoperative LAVi reduction of 29 ± 26%. Younger patients (aged <60 years) demonstrated a significantly greater degree of LARR (p = 0.022). A high preoperative LAVi was found to be an independent predictor of impaired reverse remodeling (OR 0.98, p = 0.002, 95% CI 0.97-0.99). Conclusion: Following MVS, LARR was observed in the majority of patients studied, including those with a high preoperative LAVi, but to a lesser extent. Patients with preoperative LA enlargement should be closely monitored, with a low threshold for surgical admittance, as the potential for postoperative LARR decreases with increasing preoperative LAVi.

The Journal of Heart Valve Disease 2013;22:2-10