Preoperative Risk Factors for Acute Postoperative Atrial Fibrillation in Patients Undergoing Mitral Valve Repair for Degenerative Mitral Regurgitation: Insights Into Cardiac Geometry

Abstract

Background: Postoperative atrial fibrillation (POAF) commonly occurs following surgical repair of degenerative mitral regurgitation (DMR) and is associated with unfavorable outcomes. This study aimed to identify preoperative risk factors for acute POAF in patients undergoing mitral valve repair for DMR, with a specific focus on the role of preoperative echocardiography. Methods: A retrospective study was conducted involving 1127 DMR patients who underwent mitral valve repair between 2017 and 2022. The primary endpoint was the occurrence of acute POAF within 30 days after surgery. Univariate and multivariate logistic regression analyses were performed to identify risk factors for POAF. Additionally, subgroup analyses were conducted to evaluate the predictive value of preoperative parameters for the development of acute POAF. Results: Acute POAF was observed in 152 patients (13.5%). After adjusting for covariates, multivariate analysis revealed that age (odds ratio (OR) 1.05; 95% confidence interval (CI) 1.03–1.07, p < 0.001), hypertension (OR 1.50; 95% CI 1.03–2.21, p = 0.037), left ventricular ejection fraction (OR 0.95; 95% CI 0.92–0.98, p = 0.004), and left atrial enlargement (OR 1.03; 95% CI 1.00–1.06, p = 0.019) were independent predictors of acute POAF. The interventricular septum (IVS) thickness demonstrated a strong association with acute POAF (OR 1.21; 95% CI 1.06–1.38, p = 0.005). The optimal cut-off value for the IVS thickness in predicting acute POAF was 11.0 mm. The adjusted OR of association between an IVS thickness >11 mm and acute POAF was 1.73 (95% CI 1.03–2.89, p = 0.037). The IVS thickness was consistently identified as a significant predictor of POAF in the subgroup analyses. Conclusions: Preoperative assessment of clinical morbidity and echocardiographic parameters, particularly IVS thickness, can be valuable in identifying high-risk patients for acute POAF and informing targeted strategies for prevention and management.