Early left atrial reverse normalization after minimally invasive mitral valve repair: a retrospective cohort study

Background Left atrial (LA) dilation is a common adaptive response to mitral regurgitation (MR), resulting from chronic volume overload. LA volume indexed to body surface area (LAVi) after mitral valve surgery has been associated with long-term mortality after surgery. This study aims to assess early postoperative changes in LAVi following minimally invasive mitral valve repair. Methods We retrospectively reviewed 138 patients who underwent mitral valve repair at our institution from April 2023 to May 2025. Of these, 59 patients had complete transthoracic echocardiographic and clinical data, including preoperative and predischarge assessments. LA volume was measured using the biplane method of disks and indexed to body surface area. LA dilation was defined as LAVi > 34 mL/m2. Early LA normalization after surgery was defined as a normalization of LAVi post-operative (LAVi < 34 mL/m2). Results All the patients had undergoing mitral valve repair resulted to have a dilated LA with a mean pre-operative LAVi of 57.8 ± 18.7 mL/m2. In the immediate postoperative course 23 patients (38.9%) patients normalized LAVi measure. Patients who did not normalize LA size after surgery had a significantly larger pre-operative LA (LAVi 63.4 ± 20.2 mL/m2) than patients who normalized LA (LAVi 48.9 mL/m2 ± 11.9 mL/m2, p-value= 0.02). This difference persisted on the immediate post-operative echocardiogram (49.2 ± 13.4 vs 28.6 ± 4.5 mL/m2, p-value< 0.01). The optimal pre-operative LAVi cut-off point to predict LA normalization after surgery was found to be 54.8 mL/m2 with an area under the curve (AUC 0.74, accuracy 0.71, sensitivity 0.66, specificity 0.78, Fig.1). Conclusions Early LAVi normalization can be detected after mitral valve repair in almost 40% of the patients. A pre-operative LAVi >= 54.8 mL/m2 is a negative predictor of LAVi normalization. Further, larger studies with longer follow-up are needed to evaluate the clinical and echocardiographic impact of these findings.