Development and Validation of a Risk Score for Predicting 1-Year Mortality Risk of STEMI Based on a Nationwide Cohort in China

Abstract BackgroundA risk assessment for identifying long-term risk of post-discharge mortality in Chinese STEMI patients remains a concern. The aim of this study is to establish a bedside available risk scoring system for predicting 1-year mortality risk among Chinese STEMI patients. Methods STEMI patients(n=12611) were enrolled from the China STEMI Care Project Phase 2(CSCAP-2) collected between 2015 and 2016. Confounding bias was controlled using propensity score matching. Epidemiological, clinical, laboratory, and imaging variables, treatment strategy and medicine records were screened using extreme gradient boosting and nomogram according to the hazard ratio of Cox regression analysis to construct a predictive score. A validation cohort included 7342 patients collected in 2017 from CSCAP-2 was analyzed using receiver ROC and expectation (E)/observation (O) ratio to validate the risk scoring system. Results From 39 potential predictors, 8 variables were independent predictive factor and were included in the risk score: Killip class, early reperfusion strategy, Non-PCI intraoperative anticoagulants, heart rate, gender, age, anterior-wall myocardial infarction (AWMI) and inferior-wall myocardial infarction (IWMI). The new model demonstrated an excellent discrimination and calibration. The c-statistic and E/O ratio were 0.87(95%CI, 0.80-0.93) and 1.14(95%CI, 0.93-1.39) in the train set, 0.88 (95%CI, 0.78-0.96) and 1.15(95%CI, 0.85-1.56) in the test set, meanwhile, 0.89(95%CI, 0.82-0.95) and 1.00(95%CI, 0.81-1.23) in the validation cohort. The score has better sensitivity than the GRACE score and can recognize risk stratification among STEMI patients (P<0.001).Conclusions We developed a risk scoring system for predicting 1-year mortality risk of STEMI in a large Chinese population. The new score is easy-to-use and demonstrating a good discriminatory accuracy in predicting both short-term and long-term mortality risk in Chinese patients with STEMI.