TIMI Risk Index (TRI) — STEMI 30-Day Mortality Calculator

The TIMI Risk Index (TRI) is a simple bedside calculation that provides a rapid estimate of 30-day mortality risk in patients presenting with ST-elevation myocardial infarction (STEMI). Derived from the large TIMI 9 and InTIME-II clinical trials, TRI uses three universally available parameters at presentation: heart rate, systolic blood pressure, and age. The formula TRI = (Heart Rate × [Age / 10]²) / Systolic Blood Pressure produces a score that stratifies patients into risk deciles with 30-day mortality ranging from < 1% (lowest decile) to > 35% (highest decile). TRI facilitates rapid risk communication and guides intensity of initial STEMI management.