ObjectiveTo explore the association between preoperative, perioperative parameters, especially estimated glomerular filtration rate (eGFR) and postoperative atrial fibrillation (POAF) after modified extended Morrow procedure.MethodsA total of 300 hypertrophic obstructive cardiomyopathy (HOCM) patients who underwent modified extended Morrow procedure in our hospital from January 2012 to March 2018 were collected. There were 197 (65.67%) males and 103 (34.33%) females with an average age of 43.54±13.81 years. Heart rhythm was continuously monitored during hospitalization. The patients were divided into a POAF group (n=68) and a non-POAF group (n=232). The general data, perioperative parameters and echocardiographic results were collected by consulting medical records for statistical analysis. Univariate and multivariate logistic regression models were used to analyze the risk factors for POAF.ResultsOverall incidence of POAF during hospitalization was 22.67% (68/300). Compared with patients without POAF, patients with POAF were older, had higher incidence of chest pain and syncope, lower level of preoperative eGFR, higher body mass index and heart function classification (NYHA), larger preoperative left atrial diameter and left ventricular end diastolic diameter, and longer ventilator-assisted time, ICU stay and postoperative hospital stay. Age, heart function classification (NYHA)≥Ⅲ, hypertension, syncope history and eGFR were independent risk factors for POAF. Receiver operating characteristic curve analysis showed that the area under the curve of eGFR was 0.731 (95%CI 0.677-0.780, P<0.001), and the sensitivity and specificity were 82.4% and 57.8%, respectively.ConclusionIncreased age, high preoperative heart function classification (NYHA), hypertension, preoperative syncope history and decreased eGFR are independent risk factors for POAF in HOCM patients who underwent surgical septal myectomy. Preoperative decreased eGFR can moderately predict the occurrence of POAF after modified extended Morrow procedure.