Killip Classification

Bedside heart-failure severity in acute myocardial infarction

Clinical class

I — no clinical signs of heart failure

II — rales/crackles, S3 gallop, or raised JVP

III — frank acute pulmonary oedema

IV — cardiogenic shock (hypotension, hypoperfusion)

Evidence

Original publication

Killip T 3rd, Kimball JT. Treatment of myocardial infarction in a coronary care unit: a two year experience with 250 patients. Classified acute MI by bedside heart-failure signs (I none, II rales/S3, III pulmonary oedema, IV cardiogenic shock); in-hospital mortality was roughly 6%, 17%, 38%, and 81%.

American Journal of Cardiology, 1967

Open source

Guideline

Killip class remains a component of the GRACE and TIMI-STEMI risk scores and of ACS guideline risk stratification; absolute mortality in the reperfusion era is considerably lower than in the 1967 series, but each higher class still carries a stepwise increase in risk.

Last reviewed: 2026-09

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