Age at Presentation

Age < 65 years+0Age 65–74 years+2Age ≥ 75 years+3

History of Diabetes, Hypertension, or Angina

None of the above+0Diabetes, hypertension, or angina present (any or all)+1

Systolic Blood Pressure at Presentation

SBP ≥ 100 mmHg (hemodynamically stable)+0SBP < 100 mmHg (hemodynamic compromise)+3

Heart Rate at Presentation

HR ≤ 100 bpm (normal or bradycardic)+0HR > 100 bpm (tachycardia — reflects impaired cardiac output)+2

Killip Class at Presentation

Killip Class I — No signs of heart failure+0Killip Class II, III, or IV — Any signs of heart failure or cardiogenic shock+2

Body Weight

Weight ≥ 67 kg+0Weight < 67 kg+1

Anterior ST-Elevation or Left Bundle Branch Block (LBBB) on Presenting ECG

Inferior, lateral, or posterior STEMI — no LBBB+0Anterior ST-elevation (V1–V4) or new/presumed new LBBB+1

Time from Symptom Onset to Reperfusion Therapy

Time to treatment ≤ 4 hours (within treatment window)+0Time to treatment > 4 hours (prolonged ischemic time)+1

TIMI Risk Score for STEMI