The Effect Of High BMI On Perioperative Period And Prognosis Of Patients Undergoing Open Heart Valve Surgery

Background and objective:At present,there are more than 200,000 cardiac surgery cases in China every year,of which valve surgery accounts for 20%?25%of the total.With obesity becoming a worldwide epidemic,the number of obese patients undergoing valve surgery is growing.Obesity can not only cause and worsen diseases such as type 2diabetes,cardiovascular disease,kidney disease,obstructive sleep apnea,etc,but also more easily lead to postoperative mediastinal inflammation,acute kidney injury,delayed extubation and other complications after cardiac surgery,resulting in higher mortality.But some studies have found that obese patients have a better prognosis in the state of atrial fibrillation,peripheral vascular disease and aortic atherosclerosis,heart failure,acute respiratory distress syndrome and other diseases,which is called"obesity paradox",and obesity is often diagnosed by BMI in these studies,it is also called"BMI paradox".Many studies have also shown that there is a paradox of obesity in cardiac surgery,which is mostly heterogeneous and analysis mostly coronary artery bypass grafting.So the effect of obesity on other types of cardiac surgery,especially valve surgery,is unclear.therefore,this study investigated the effect of high BMI,especially obesity,on perioperative and prognosis of patients undergoing open heart valve surgery by comparing differences between different body mass index patients who was undergoing open heart valve surgery,thus providing a theoretical basis for clinical practice.Methods:From January 2014 to April 2017,412 cases were selected according to the inclusion criteria and exclusion criteria.Patients was divided into normal weight group(18.5kg/m~2?BMI<23.9kg/m~2),overweight group(24.0kg/m~2?BMI<27.9kg/m~2)and obese group(BMI?28.0kg/m~2)according to the Chinese criteria established by WHO.The preoperative data,operation related data,postoperative related data,postoperative complications and mid-term survival data were collected in each group,and the differences between each group were compared.Results:1.There were 196 patients in the normal weight group,160 patients in the overweight group,56 patients in the obese group,The proportion of obese patients was13.6%,and that of overweight and obese patients was 52.4%.2.Compared to normal weight group,there is higher prevalence of hypertension and diabetes in the overweight and obese groups(p<0.05),preoperative ultrasound in overweight and obese groups suggested a lower rate of liver congestion(p<0.05),the preoperative combined atrial fibrillation ratio was lower in overweight and obese groups(p<0.05),the history of preoperative myocardial infarction in overweight group was more common(p<0.05),preoperative cardiac function(NYHA grade?3)was less(p<0.05)in obese patients.Compared with the normal weight group and the obese group,the preoperative coronary heart disease rate was higher in the overweight group(p<0.05).3.Compared with the normal weight and overweight groups,the patients in the obese group had less drainage on the day after operation(p<0.05).Compared with normal weight group,total autologous blood transfusion was higher(p<0.05)and the total erythrocyte infusion was less(p<0.05)in overweight and obese groups..4.In univariate cox regression analysis,age,atrial fibrillation,peripheral vascular disease,and liver congestion were risk factors for mid-term postoperative survival(p<0.05).In multivariate cox regression analysis,age,atrial fibrillation,peripheral vascular disease were risk factors for postoperative mid-term survival(p<0.05),and preoperative LVEF were protective factors for postoperative mid-term survival(p<0.05).5.There was no statistical difference in postoperative complications and mid-term survival among the three groups(p>0.05).Conclusion:1.The proportion of patients with high BMI in valve surgery was much lower than that in integral cardiac surgery.2.Valvular disease patients with high BMI had a lower proportion of preoperative heart failure than patients with normal BMI,while high BMI patients had lower proportion of preoperative atrial fibrillation than patients with normal BMI.3.High BMI patients had less bleeding and blood transfusion during valve surgery than with normal BMI patients.4.Age,atrial fibrillation,and peripheral vascular disease were independent risk factors for mid-term survival in patients undergoing open heart valve surgery.There was no significant difference between postoperative complications and mid-term survival rate between each BMI group.High BMI did not affect the prognosis of patients undergoing open heart valve surgery.5.There was no obesity paradox found in valvular surgery,that is,high BMI has no protective effect on patients with open heart valve surgery.6.It's still needs further exploration for the effect of BMI on pulmonary and renal organ complications after cardiac valve surgery.