For healthcare professionals
Killip classification
The Killip classification grades heart failure at the bedside in acute myocardial infarction (MI), from class I (no signs of heart failure) to class IV (cardiogenic shock). It is a classification, not a score: the most severe finding sets the class. This tool is written for clinicians and is not a diagnosis.
Bedside findings
For adults with acute myocardial infarction. Nothing you enter leaves this page.
What you will see
The Killip class, its definition in two open sources and the in-hospital mortality printed for that class.
Educational only, not medical advice. A class does not replace clinical judgment.
Source
Killip and Kimball, American Journal of Cardiology 1967 (cited, not quoted). The class definitions are quoted from Hashmi and colleagues, Cureus 2020 (CC BY), and Liu and colleagues, Frontiers in Medicine 2022 (CC BY 4.0). The tests check each class, the printed mortality figures and that the cohort counts add up to 485.
Validated in
Killip and Kimball described 250 patients treated in a coronary care unit over two years in the 1960s. The mortality figures here come from later STEMI cohorts: the EURO Heart Survey ACS registry and a 485-patient single-centre study in Pakistan of STEMI patients with left ventricular failure, with in-hospital mortality within 15 days (Hashmi 2020).
Limits
A bedside classification from physical examination, so it depends on the examiner. Mortality rates come from specific cohorts and eras and differ widely between them; they are not a prediction for one patient. The two open sources word class II differently (see below). Not a substitute for a full risk assessment such as the TIMI or GRACE scores.
The four classes
As printed in Hashmi and colleagues 2020 (Hashmi 2020) and Liu and colleagues 2022 (Liu 2022), both citing the original classification (Killip 1967):
| Class | Hashmi 2020 | Liu 2022 |
|---|---|---|
| I | "patients without any clinical sign of HF" | "no signs of heart failure" |
| II | "patients with crackles or rales in the lungs, elevated jugular venous pressure, and an S3 gallop" | "signs indicating mild to moderate heart failure (i.e., third heart sound gallop, rales halfway up the lung fields, or elevated jugular venous pressure)" |
| III | "patients with evident acute pulmonary edema" | "pulmonary edema" |
| IV | "patients with cardiogenic shock or hypotension (systolic blood pressure < 90 mmHg) and features of low cardiac output (oliguria, cyanosis, or impaired mental status)" | "cardiogenic shock or refractory hypotension" |
HF means heart failure. Where the sources differ: for class II, Hashmi and colleagues join the signs with "and", while Liu and colleagues list them with "or" and add "rales halfway up the lung fields". For class IV, Hashmi and colleagues give a blood pressure threshold and signs of low cardiac output; Liu and colleagues write "refractory hypotension". The tool uses the broader "or" reading for class II: any of the listed signs.
In-hospital mortality by class
These are group rates printed in open sources, with their cohort and era. They vary widely between cohorts and are not a prediction for one patient.
| Class | EURO Heart Survey ACS registry, STEMI | Hashmi 2020, STEMI, Lahore |
|---|---|---|
| I | 2.9% | 39 of 395 (9.9%) |
| II | 13.6% | 4 of 46 (8.7%) |
| III | 27.4% | 25 of 27 (92.6%) |
| IV | 50.5% | 17 of 17 (100%) |
The EURO Heart Survey figures (19,158 cases) are from a 2011 conference abstract by Papp and colleagues (Papp 2011), as printed in the introduction of Hashmi and colleagues (Hashmi 2020). The Hashmi cohort was a three-year retrospective study of 485 STEMI patients aged 40 to 70 with left ventricular failure secondary to STEMI, at one cardiology department in Lahore, Pakistan; mortality was counted in hospital within 15 days of the heart attack (Hashmi 2020). Because every patient in that study had left ventricular failure, its class I death rate is much higher than in the EURO Heart Survey, and its small class II to IV groups explain why class I and II look alike there.
Related tools
For a fuller risk estimate in acute coronary syndrome, see the TIMI risk score. In the emergency department, the HEART score grades chest pain, and the CRUSADE bleeding score estimates in-hospital major bleeding in NSTEMI. Other bedside scores are listed under For healthcare professionals.
Sources
- Killip T 3rd, Kimball JT. Treatment of myocardial infarction in a coronary care unit: a two year experience with 250 patients. Am J Cardiol. 1967;20(4):457-464. doi:10.1016/0002-9149(67)90023-9. PMID 6059183. Original classification (cited; the class definitions used here are taken from Hashmi 2020 and Liu 2022, CC BY). doi.org/10.1016/0002-9149(67)90023-9
- Hashmi KA, Adnan F, Ahmed O, et al. Risk assessment of patients after ST-segment elevation myocardial infarction by Killip classification: an institutional experience. Cureus. 2020;12(12):e12209. doi:10.7759/cureus.12209. PMID 33489617. Open access (CC BY). Methods (Killip class definitions), Introduction (EURO Heart Survey mortality per class) and Results (in-hospital mortality per class). pmc.ncbi.nlm.nih.gov/articles/PMC7815264/
- Liu Y, Feng DJ, Wang LF, et al. The impact of cardiac dysfunction based on Killip classification on gastrointestinal bleeding in acute myocardial infarction. Front Med (Lausanne). 2022;9:865663. doi:10.3389/fmed.2022.865663. PMID 35814749. Open access (CC BY 4.0). Methods (Killip class definitions). pmc.ncbi.nlm.nih.gov/articles/PMC9260836/
- Papp A, Bueno H, Gierlotka M, et al. Value of Killip classification first described in 1967 for risk stratification of STEMI and NSTE-ACS in the new millennium: lessons from the EURO Heart Survey ACS Registry. J Am Coll Cardiol. 2011;57(14):E1062. Conference abstract (cited; the mortality figures used here are as printed in Hashmi 2020). doi.org/10.1016/S0735-1097(11)61062-0
Written and maintained by the uncovermyrisk.com editorial team. We do not have a medical reviewer; every claim links to its primary source above. Last reviewed: 2026-11-03. Spotted an error? See About.