Thrombolysis in Myocardial Infarction (TIMI) Risk Index predicts long-term mortality and heart failure in patients with ST-elevation myocardial infarction in the TIMI 2 clinical trial

Abstract

TIMI (Thrombolysis in Myocardial Infarction) Risk Index (TRI) is a simple bedside score that predicts 30-day mortality in patients with ST-elevation myocardial infarction (MI). We sought to evaluate whether TRI was predictive of long-term mortality and clinical events. In the TIMI 2 trial, 3,153 patients (mean age 57 +/- 10 years, 82% men) were randomized to invasive (n = 1,583) versus conservative (n = 1,570) strategy postfibrinolysis with median follow-up of 3 years. TIMI Risk Index was divided into 5 groups. The primary end point was all-cause mortality. Secondary analyses included recurrent MI, congestive heart failure (CHF), and combined end points. When compared with group 1, mortality in group 5 was more than 5-fold higher (hazard ratio [HR] 5.83, P < .0001) and was also increased in group 4 (HR 2.80, P < .0001) and group 3 (HR 1.96, P = .002) (c statistic 0.69). No difference was seen between groups 1 and 2 (P = .74). A similar increasing gradient effect was seen across TRI strata with group 5 having the highest risk for CHF (HR 4.13, P < .0001) and the highest risk for composite death/CHF (HR 4.35, P < .0001) over group 1. There was no difference in recurrent MI between the groups (P = .22). After controlling for other risk indicators, the relationship between TRI and mortality remained significant: group 5, HR 4.11, P < .0001; group 4, HR 2.14, P = .0009; group 3, HR 1.69, P = .02. When stratified by TRI groups, no differences in mortality or composite death/MI were found between treatment strategies. The simple TRI can predict increased long-term mortality, CHF, and composite death/CHF.