TIMI risk score for ST-elevation myocardial infarction: A convenient, bedside, clinical score for risk assessment at presentation - An intravenous nPA for treatment of infarcting myocardium early II trial substudy

Background-Considerable variability in mortality risk exists among patients with ST-elevation myocardial infarction (STEMI), Complex multivariable mod els identify independent predictors and quantify their relative contributio n to mortality risk but are too cumbersome to be readily applied in clinica l practice. Methods and Results-We developed and evaluated a convenient bedside clinica l risk score for predicting 30-day mortality at presentation of fibrinolyti c-eligible patients with STEMI, The Thrombolysis in Myocardial Infarction ( TIMI) risk score for STEMI was created as the simple arithmetic sum of inde pendent predictors of mortality weighted according to the adjusted odds rat ios from logistic regression analysis in the Intravenous nPA for Treatment of Infarcting Myocardium Early II trial (n=14 114). Mean 30-day mortality w as 6.7%. Ten baseline variables, accounting for 97% of the predictive capac ity of the multivariate model, constituted the TIMI risk score. The risk sc ore showed a >40-fold graded increase in mortality, with scores ranging fro m 0 to >8 (P<0.0001); mortality was <1% among patients with a score of 0. T he prognostic discriminatory capacity of the TIMI risk score was comparable to the full multivariable model (c statistic 0.779 versus 0.784), The prog nostic performance of the risk score was stable over multiple time points ( 1 to 365 days). External validation in the TIMI 9 trial showed similar prog nostic capacity (c statistic 0.746). Conclusions-The TIMI risk score for STEMI captures the majority of prognost ic information offered by a full logistic regression model but is more read ily used at the bedside. This risk assessment tool is likely to be clinical ly useful in the triage and management of fibrinolytic-eligible patients wi th STEMI.