Validity of a Simple ST-Elevation Acute Myocardial Infarction Risk Index

Abstract
Background— Risk-stratification scores derived from randomized clinical trial (RCT) data should be evaluated in community-based populations. A simple risk-stratification index for patients with ST-segment elevation myocardial infarction derived from an RCT population was recently proposed, but it has not been validated in a community-based cohort. Methods and Results— We evaluated the simple risk index using data from 49 711 patients ≥65 years of age hospitalized with ST-elevation myocardial infarction. We evaluated the distribution of patients in the 5 simple risk index groups, compared observed and published 30-day mortality rates, and assessed the score’s discrimination and calibration. The simple risk index provided poor discrimination (c=0.62) and calibration (goodness of fit P Conclusions— The limited performance of the simple risk index highlights the limitations of applying prognostic models derived in RCT populations to the general population of patients 65 years and older. Prognostic scores must be validated in community-based cohorts before integration into clinical practice.