Risk Factors Of New-onset Atrial Fibrillation Early After Cardiac Valve Surgery

Background&objective:Postoperative atrial fibrillation(POAF)is a common complication after cardiac surgery.It can lead to hemodynamic instability and is associated with a poor prognosis,both in the short term and long term.In addition,its occurrence increases the risk of complications,such as renal failure,thrombosis and stroke,which significantly increases the rate of postoperative mortality.Although many studies have investigated the risk factors of POAF,most of the subjects in these studies were patients who underwent coronary artery bypass grafting(CABG).In order to identify the independent predictors of POAF and provide a clinical basis for its early prevention,this study analyzed the risk factors of new-onset atrial fibrillation after simple cardiac valve surgery.Methods:A total of 302 patients who underwent simple heart valve surgery in the second affiliated Hospital of Nanchang University from January 2018 to December 2020 were recruited based on the inclusion and exclusion criteria.According to the occurrence of new-onset atrial fibrillation after operation,the patients were divided into two groups:POAF group and non-POAF group.Then,the baseline data of the patients and relevant data of before,during and after operation were retrospectively analyzed and compared between the two groups.We used single-factor analysis to screen the related factors that may affect the occurrence of POAF.Next,the statistically significant factors(p<0.05)were analyzed using multi-factor logistic regression to determine the independent risk factors of POAF.After drawing the receiver operating characteristic(ROC)according to the independent risk factors and calculating the area under the curve(AUC),the cut-off point and the corresponding sensitivity and specificity were obtained.Results:Among the 302 patients who underwent simple heart valve surgery,120(39.7%)had POAF and 182(60.3%)did not have.By comparing the related risk factors between the POAF and non-POAF groups,significant differences were found in the factors of age,preoperative cardiac function grade,preoperative left atrial diameter index,duration of intraoperative anesthesia,type of valvular operation,postoperative urea,postoperative WBC,postoperative blood glucose and postoperative fever degree.The multi-factor logistic regression analysis showed that the preoperative left atrial diameter index[OR=0.938,95%CI(0.891-0.988)],duration of intraoperative anesthesia[OR=0.718,95%CI(0.533-0.965)],postoperative WBC[OR=0.892,95%CI(0.831-0.957]]and postoperative fever degree[OR=0.422,95%CI(0.277-0.645)]were independent risk factors of POAF.The ROC curves were separately drawn according to the preoperative left atrial diameter index,duration of intraoperative anesthesia,postoperative WBC,in which the AUC and 95%confidence interval(CI)were 0.602(0.537-0.666),0.589(0.524-0.645)and 0.625(0.561-0.689),respectively.The cut-off point of left atrial diameter index was 27.08mm/m2,and the corresponding sensitivity and specificity were 0.583 and 0.61,respectively.The cut-off point of duration of intraoperative anesthesia was 3.625h,and the corresponding sensitivity and specificity were 0.758 and 0.379,respectively.The cut-off point of postoperative WBC was 12.87*109/L,and the corresponding sensitivity and specificity were 0.65 and 0.571,respectively.Compared with the non-POAF group,the POAF group had significantly longer ICU stay and hospitalization period,higher total hospitalization costs and higher risk of developing renal insufficiency.No significant difference was observed between the two groups regarding some postoperative adverse events,such as pleural/pericardial effusion,poor incision healing or pulmonary infection.Conclusion:Among the patients who underwent simple heart valve surgery,39.7%developed POAF.The preoperative left atrial diameter index,duration of intraoperative anesthesia,postoperative WBC and postoperative fever degree are independent risk factors of POAF.Larger left atrial diameter index,longer anesthetic time,higher postoperative WBC and moderate fever indicate that the patients are more likely to develop POAF.The prevention of POAF may shorten the length of ICU stay and hospitalization,reduce the cost of hospitalization and lower the occurrence of postoperative renal insufficiency.