Age shock index and age-modified shock index are strong predictors of outcomes in ST-segment elevation myocardial infarction patients undergoing emergency percutaneous coronary intervention

Abstract

Early identification of high-risk patients provides clinicians with greater decision-making time and better informs strategies to cope with disease. The predictive values of age shock index (age SI) and age-modified shock index (age MSI) in ST-segment elevation myocardial infarction (STEMI) patients undergoing emergency percutaneous coronary intervention (PCI) have rarely been reported, especially compared with those for SI, MSI, and the Global Registry of Acute Coronary Events (GRACE) risk score. Nine hundred and eighty-three STEMI patients undergoing emergency PCI between January 2014 and September 2017 were analyzed in a retrospective cohort study. The primary outcomes were rates of in-hospital cardiovascular events, and 6-month and long-term all-cause mortality. In multivariate analyses, the predictive values of age SI and age MSI were comparable to that of the GRACE score, but superior to those of SI and MSI for in-hospital cardiac mortality [age SI: odds ratio (OR) = 1.05, P < 0.001, area under the receiver operating characteristic (ROC-AUC) = 0.805, P < 0.001; age MSI: OR = 1.04, P < 0.001, ROC-AUC = 0.813, P < 0.001; GRACE score: OR = 1.03, P < 0.001, ROC-AUC = 0.827, P < 0.001], 6-month all-cause mortality (age SI: OR = 1.04, P < 0.001, ROC-AUC = 0.791, P < 0.001; age MSI: OR = 1.03, P < 0.001, ROC-AUC = 0.801, P < 0.001; GRACE score: ROC-AUC = 0.828, P < 0.001), long-term all-cause mortality [age SI: hazard ratio (HR) = 1.06, P < 0.001, ROC-AUC = 0.798, P < 0.001; age MSI: HR = 1.04, P < 0.001, ROC-AUC = 0.84, P < 0.001; GRACE score: ROC-AUC = 0.822, P < 0.001] and post-discharge all-cause mortality (age SI: HR = 1.05, P < 0.001, ROC-AUC = 0.78, P = 0.001; age MSI: HR = 1.05, P < 0.001, ROC-AUC = 0.789, P < 0.001; GRACE score: ROC-AUC = 0.812, P < 0.001). Age SI and age MSI are stronger predictors than SI and MSI for in-hospital cardiovascular events, and 6-month and long-term all-cause mortality in STEMI patients undergoing emergency PCI. Age SI and age MSI appear to be convenient and simpler indicators than the GRACE score.