Risk Facors Analysis And Prediction Model Construction Of Myocardial Injury After Noncardiac Surgery In The Elderly

Objective:To determine the incidence of postoperative myocardial injury after non-cardiac surgery(MINS)and its association with postoperative outcome in elderly patients over 65 years under the new diagnostic criteria.By analyzing the risk factors of MINS,a nomogram prediction model was constructed and its predictive efficacy was evaluated.Methods:The study was a single center retrospective case-control trial.The trial enrolled a total of 692 elderly patients who underwent noncardiac surgery and had high-sensitivity troponin T(hs-TnT)testing before and within 30 days after surgery at the First Affiliated Hospital of Soochow University between October 2017 and December 31 2021.All patients were divided into training set(n=623)and validation set(n=69)using random sampling in a 9:1 ratio.Patients in the training set were divided into a non-MINS group(n=446)and a MINS group(n=177)according to whether or not MINS occurred,and univariate analysis was performed.Logistic regression analysis was used to identify independent risk factors or protective factors for MINS and to construct a nomogram model with R.The nomogram model was evaluated using receiver operating characteristic curve(ROC)curve and calibration curve in the training set versus the validation set.Results:Among 692 patients in final analysis,a total of 201(29.05%)patients developed MINS.The proportion of postoperative return to the ICU(57.71%versus 41.55%,P=0.002)and in-hospital mortality(14.43%versus 1.63%,P<0.0001)in the MINS group were significantly higher than non-MINS group.Patients who developed MINS had a median hospital stay of 17 days,which was significantly longer than those who did not(17 versus 15,P=0.0026).Multivariate analysis showed that cardiac dysfunction(OR=5.133,95%CI:1.422-19.799,P=0.0130),elevated serum lactic dehydrogenase(LDH)level(OR=1.004,95%CI:1.002-1.007,P=0.0028),ventricular wall motion disorders(OR=2.31,95%CI:1.013-5.181,P=0.0028),prolonged duration of low diastolic blood pressure(DBP)during operation(OR=1.008,95%CI:1.002-1.015,P=0.0095)were independent risk factors for the development of MINS after non cardiac surgery in elderly patients over 65,while the increased serum albumin(ALB)level(OR=0.952.95%CI:0.907-0.998,P=0.0432)was a protective factor for MINS.The nomogram prediction model of MINS was constructed according to the 5 factors above,and the AUCs were 0.722(95%CI:0.673-0.772),0.726(95%CI:0.676-0.776)in the training set and validation set,respectively.The calibration curve fit to the ideal curve well in the training set and suboptimally in the validation set.Conclusions:The incidence of MINS was 29.05%in elderly patients over 65 years,and it was associated with postoperative return to the ICU and in-hospital mortality strongly.Cardiac dysfunction,elevated serum lactic LDH level,wall motion disorder.and prolonged duration of low DBP during operation were independent risk factors for MINS in over 65 elderly patients.Besides,the increased serum ALB level was a protective factor.The MINS nomogram model discriminated and calibrated well which may help clinicians recognize high-risk patients early.