Risk Factors Of In-Hospital And Mid-Long Term Mortality After Aortic Valve Replacement

【Objective】The objectives of this study were to assess the effectiveness of the EuroSCOREⅡ and cardiac valve surgical risk prediction model of our country in predicting the risk for hospital mortality of adult patients after primary aortic valve replacement;and evaluate results and identify predictors of in-hospital and mid-long term mortality.【Methods】 1、 Validation of the EuroSCOREⅡ and cardiac valve surgical risk prediction model of ourcountry in adult patients after primary aortic valve replacement.(1)Dates from 1317 patients undergoing primary aortic valve replacement between 2000 and 2014 were prospectively collected according to the definitions of the EuroSCOREⅡ and cardiac valve surgical risk prediction model of our country.Patients with cardiac surgery history or concomitant other valve or aortic replacement were excluded from this study.(2)The predicted operative mortality of EuroSCOREⅡ and cardiac valve surgical risk prediction model of our country for aortic valve procedures was performed by the logistic regression formulas of risk models.Based on the definition of weight of the intervention in EuroSCOREⅡ,patients were divided into1-procedure,2-procedures and 3-procedures groups.(3)The validation of those two models depended on the assessment of calibration and discrimination.Calibration of the model was evaluated by Hosmer-Lemeshow good-of-fit test(H-L test)and Observed/Expected mortality ratio(O/E ratio).Discrimination of the model was evaluated by the area under receiver operating characteristic curve(AUC).2、Predictors of in-hospital mortality associated with aortic valve replacement.(1)The study consisted of 1317 adult patients who underwent primary aortic valve replacement at our hospital between 2000 and 2014.Patients with cardiac surgery history or combined valve or aortic replacement were excluded from this study.In-hospital mortality was the end point.(2)On the basis of whether in-hospital death occurred postoperatively,this cohort of patients was divided into the death group and non-death group.The potential risk foctors of in-hospital mortality was assessed with a univariate analysis.(3)Variables with significant statistical meaning in the univariate analysis were entered into a binary logistic regression analysis.3、Predictors of mid-long term mortality of patients undergoing aortic valve replacement.(1)547 patients undergoing aortic valve replacement from Jan 2010 to Dec 2014 were enrolled in the study.Patients with cardiac surgery history or combined valve or aortic replacement were excluded from this study.Mid-term mortality and major adverse cardiac and cerebrovascular events were the end points.(2)The potential risk foctors of in-hospital mortality was assessed with a COX univariate analysis.(3)All variables significant in the univariate analysis were entered into a multivariable COX regression analysis.【Results】 1、Validation of the EuroSCOREⅡ and cardiac valve surgical risk prediction model of our country in adult patients after primary aortic valve replacement.(1)The overall in-hospital mortality was 3.79%.The expected mortality of the EuroSCOREⅡ and cardiac valve surgical risk prediction model of our country was 2.13% and 5.02%.The observed/expected ratio was 1.78 and 0.75.The EuroSCOREⅡ significantly underpredicted the observed mortality(H-L test P<0.05).The cardiac valve surgical risk prediction model of our country showed a tendency to overestimated the observed mortality(H-L test P<0.05).(2)The observed mortality of each group was 2.40%,6.14% and 5.29%,respectively.The EuroSCOREⅡ showed a good tendency to predict the observed mortality of 3-procedures group(O/E ratio = 0.999;H-L test P = 0.58).But it underpredicted observed mortality in 1-procedure and 2-procedures group,significantly(O/E ratio > 1;H-L test P<0.05).The cardiac valve surgical risk prediction model of our country showed a tendency to overestimated observed mortality in each group(O/E ratio < 1;H-L test P<0.05).(3)The the areas under receiver operating characteristic curve of the entire cohort were 0.753 for EuroSCOREⅡ and 0.787 for cardiac valve surgical risk prediction model of our country.The EuroSCORE and cardiac valve surgical risk prediction model of our country showed a good discrimination in predicting mortality of each subgroup(AUC >0.7).2、Predictors of in-hospital mortality associated with aortic valve replacement.(1)The overall in-hospital mortality was 3.79%.Cardiac death accounted for 53.3% of all-cause death.(2)Potential predictors in the univariate analysis were age,hypertesion,peripheral vascular disease,chronic pulmonary disease,creatinine,critical preoperative state,preoperative use of positive inotropic drugs,preoperative myocardial infarction,atrial fibrillation,coronary heart disease,NYHA functional class,left ventricular ejection fraction,shortening fraction,left atrial volume,mitral valve insufficiency,concomitant CABG surgery,concomitant mitral valvuloplasty,cardiopulmonary bypass(CPB)time.(3)Age,coronary heart disease,critical preoperative state,left ventricular ejection fraction and cardiopulmonary bypass(CPB)time were confirmed to be independent predictors of in-hospital mortality.3、Predictors of mid-long term mortality of patients undergoing aortic valve replacement.(1)Actual quantity of the patients who had been followed up was 486 and the follow-up rate was 88.85%.The mean follow-up period was 64.47±23.23 months.Freedom from all-cause death at 1,3 and 5 years after AVR was 98.9%、97.3% and 96.0%,respectively.There were 23 deaths,including 5 cardiac deaths,and 49 MACCEs(5 cardiac deaths,8 hospitalizations for heart failure,10 re-operations and 26 strokes)during the follow-up period.(2)Univariate COX analysis showed that age,body mass index,chronic pulmonary disease,creatinine,atrial fibrillation,coronary heart disease,NYHA functional class III-IV,left ventricular mass,left atrial volume,right atrial volume,right ventricular volume,mitral valve insufficiency,concomitant CABG surgery,concomitant tricuspid valvuloplasty,cardiopulmonary bypass(CPB)time and aortic cross-clamp time are the candidate predictors.(3)Age,body mass index,chronic pulmonary disease,left ventricular mass and coronary heart disease were confirmed to be independent predictors of mid-long term mortality.【Conclusions】1、Each of the EuroSCOREⅡ and cardiac valve surgical risk prediction model of our country gives an imprecise prediction for operative risk of individual patient with aortic valve replacement in our study.These two risk prediction models only can be used as references for clinic treatment.2、The risk of death in hospital following aortic valve replacement is higher in patients with advanced age,coronary heart disease,critical preoperative state,lower left ventricular ejection fraction and longer cardiopulmonary bypass time.3、By multivariable COX regression analysis,some potential risk factors for AVR are confirmed to be independent predictors of mid-long term mortality,which can be used to identify patients at high risk of postoperative mortality.