Patients with acute ST-elevation myocardial infarction (STEMI) at the time of presentation.
Risk stratification for in-hospital and 30-day mortality.
Identifying high-risk candidates for aggressive mechanical support or ICU admission.
Section 2
Formula & Logic
Killip Classification Reference
Class I
No clinical signs of heart failure.
Class II
Crackles in lungs, S3 gallop, or elevated JVP.
Class III
Frank pulmonary edema.
Class IV
Cardiogenic shock (hypotension/hypoperfusion).
Point Logic
01
Age: 61–70 (1 pt), >70 (2 pts)
02
History: DM, HTN, or Prior CAD (1 pt total if any)
03
Hemodynamics: SBP <100 (2 pts), HR >100 (1 pt)
04
Killip II-IV: (1 pt)
05
Anterior MI Location: (1 pt)
06
Weight < 67 kg: (1 pt)
07
Female Sex: (1 pt)
Section 3
Pearls/Pitfalls
Why Weight and Gender?
Female sex and lower body weight (<67kg) are independent predictors of higher mortality in STEMI, often associated with smaller coronary vessel size and a higher risk of bleeding complications during reperfusion therapy.
Anterior vs. Inferior
Anterior MIs typically involve the Left Anterior Descending (LAD) artery, which supplies a larger territory of the left ventricle compared to the RCA (Inferior). This results in a higher score due to the greater risk of cardiogenic shock and heart failure.
Section 4
Evidence Appraisal
Primary Derivation
TIMI risk score for ST-elevation MI: A convenient, bedside, clinical score for risk assessment at presentation.
Morrow DA et al. • Circulation.. 2000;n=2,031 patients. Validated using the TIMI 9B trial database. Demonstrated strong correlation with 30-day mortality (C-statistic 0.78).
Section 5
Literature
The TIMI 9B Legacy
Developed by the TIMI Study Group at Brigham and Women's Hospital. Unlike the UA/NSTEMI score which was derived from non-ST elevation trials, this specific score was synthesized from fibrinolytic-treated patients to help ER physicians quickly triage the highest-risk STEMI presentations.
