TIMI STEMI Score Calculator

Understanding the TIMI Risk Score for STEMI

The Thrombolysis in Myocardial Infarction (TIMI) Risk Score for ST-Elevation Myocardial Infarction (STEMI) is a validated clinical prediction algorithm developed by Morrow and colleagues from the TIMI II and InTIME II trial registries. It provides rapid bedside risk stratification to estimate 30-day all-cause mortality in acute STEMI patients presenting for reperfusion therapy (primary percutaneous coronary intervention or fibrinolysis).

Scoring System and Clinical Variables

The score is computed by assigning points to eight admission clinical variables:

• Age: Age 65 to 74 years (+2 points) or $\ge 75$ years (+3 points).
• Systolic Blood Pressure < 100 mmHg: +3 points (hemodynamic compromise / hypoperfusion).
• Heart Rate > 100 beats/min: +2 points (compensatory tachycardia).
• Killip Class II to IV: +2 points (presence of pulmonary rales, jugular venous distension, pulmonary edema, or cardiogenic shock).
• Body Weight < 67 kg (147.7 lbs): +1 point.
• Risk Factor History: +1 point if history of diabetes mellitus, hypertension, or prior angina.
• ECG Findings: +1 point for anterior ST-segment elevation or left bundle branch block (LBBB).
• Time to Reperfusion > 4 hours: +1 point (delayed presentation increases myocardial necrosis).

30-Day Mortality Risk Stratification

The total score ranges from 0 to 14 points, categorizing patients into low, intermediate, and high risk:

• Score 0 (0.8% mortality): Low risk.
• Score 1 (1.6% mortality): Low risk.
• Score 2 (2.2% mortality): Low risk.
• Score 3 (4.4% mortality): Intermediate risk.
• Score 4 (7.3% mortality): Intermediate risk.
• Score 5 (12.4% mortality): Intermediate risk.
• Score 6 (16.1% mortality): High risk.
• Score 7 (23.4% mortality): High risk.
• Score 8 (26.8% mortality): High risk.
• Score > 8 (35.9% mortality): Very high risk.

Related Cardiac and Critical Care Tools

Assess cardiovascular risks with our related clinical scoring calculators:

• Shock Index Calculator for occult shock detection.
• Revised Cardiac Risk Index Calculator for perioperative MACE estimation.
• Stroke Volume Calculator for hemodynamic parameters.