β€οΈ TIMI Risk Score for STEMI
Thirty-day mortality from eight bedside facts.
TIMI STEMI score (0-14)
For informational purposes only, not medical advice.
The TIMI risk score for STEMI sums eight weighted bedside variables to a 0-14 score, each point mapping to a published 30-day mortality. A 78-year-old with systolic pressure under 100 and heart rate over 100 scores 3 + 3 + 2 = 8, carrying a 26.8% thirty-day mortality in the original trial cohort. Derived by Morrow and colleagues in 2000 from over 14,000 fibrinolysis-treated patients, it remains the classic bedside risk tool for ST-elevation heart attacks.
The weighting tells the clinical story: age and shock signs dominate, while history and ECG details add single points. It was built to be calculated from memory at 3 am, and it still is.
How to Use This Calculator
Select the age band, then answer the seven yes-or-no items. Points apply automatically with the correct weights, and the mortality reads straight off the published table.
Choose the age band: under 65 scores 0, 65 to 74 scores 2, 75 or older scores 3.
Answer the hemodynamic questions: systolic under 100 (3 points), heart rate over 100 (2 points), Killip class II through IV (2 points).
Answer the remaining four: weight under 67 kg, diabetes/hypertension/angina history, anterior ST elevation or bundle branch block, and treatment delay over 4 hours, one point each. Read the score and mortality.
The Score and the Mortality Table
| Score | 30-day mortality |
|---|---|
| 0 | 0.8% |
| 2 | 2.2% |
| 4 | 7.3% |
| 6 | 16.1% |
| 8 | 26.8% |
| 9 or more | 35.9% |
The mortality curve is steep: each few points roughly double the risk. That nonlinearity is the point. A score of 2 versus 6 is not three times worse, it is seven times worse, which is why the number changes triage, monitoring intensity, and family conversations.
Worked Example
A 78-year-old arrives with crushing chest pain, blood pressure 88/60, heart rate 112, clear lungs, and an anterior ST elevation, treated within 2 hours. Age 75 or older gives 3 points, systolic under 100 gives 3, heart rate over 100 gives 2, anterior STE gives 1: total 8 of 14. The table maps 8 points to 26.8% thirty-day mortality.
That number does not decide treatment; reperfusion is indicated regardless. It calibrates expectations, justifies ICU-level monitoring, and gives the family an honest frame. A young patient with an inferior STEMI and stable vitals might score 1 or 2, a completely different conversation from the same diagnosis.
Reading Your Result
Scores 0 to 2 are low risk, 3 to 5 intermediate, 6 to 8 high, and above 8 very high. One caveat: the score was derived in fibrinolysis-era patients, and modern primary PCI has better outcomes across the board, so contemporary mortality runs lower than the table. The ranking, who is sicker than whom, holds up well; the absolute percentages are pessimistic by today's standards.
My take: use TIMI STEMI for what it is, a fast, validated sorting hat. For deeper prognosis, clinicians layer on ejection fraction, renal function, and bleeding risk, none of which the score sees.
Limits
The score needs a confirmed STEMI; it means nothing applied to chest pain without ST elevation. It also predates modern PCI, high-sensitivity troponins, and contemporary medical therapy, so treat the mortality column as historical context. And it cannot see frailty, goals of care, or the hundred other things that shape a real patient's outcome.
Related Tools
Two of the score's inputs have their own checkers: the blood pressure checker and the diabetes risk calculator. For the NSTEMI cousin of this score, see our TIMI UA/NSTEMI calculator.
For informational purposes only, not medical advice. Consult a healthcare professional.
Frequently Asked Questions
What is the TIMI risk score for STEMI?
An 8-variable bedside score predicting 30-day mortality in ST-elevation heart attack, from 0 to 14 points. Age, blood pressure, heart rate, Killip class, weight, cardiac history, ECG territory, and treatment delay each contribute weighted points. Published by Morrow et al. in Circulation, 2000.
How is the TIMI STEMI score calculated?
Add: age 65-74 = 2, 75+ = 3; systolic BP under 100 = 3; heart rate over 100 = 2; Killip II-IV = 2; weight under 67 kg = 1; diabetes/hypertension/angina = 1; anterior STE or LBBB = 1; treatment delay over 4 hours = 1. Maximum 14.
What mortality does each score predict?
From the InTIME II cohort: 0 = 0.8%, 1 = 1.6%, 2 = 2.2%, 3 = 4.4%, 4 = 7.3%, 5 = 12.4%, 6 = 16.1%, 7 = 23.4%, 8 = 26.8%, 9+ = 35.9%. Modern PCI-era outcomes are better, so these read high today.
What is Killip class?
A bedside grading of heart failure in heart attack: I = no failure signs, II = crackles or raised jugular pressure, III = pulmonary edema, IV = cardiogenic shock. Classes II through IV score 2 points on the TIMI STEMI score.
Can the TIMI score be used for NSTEMI?
No, use the separate TIMI UA/NSTEMI score, which has different variables and predicts a composite of death, MI, and urgent revascularization. The STEMI score's weights and mortality table do not transfer.
Does a high TIMI score change treatment?
Reperfusion is indicated regardless of score. The score guides monitoring intensity, prognosis discussions, and sometimes transfer decisions, but it never argues against opening the artery.
Why does age dominate the score?
Age is the strongest single predictor of mortality after heart attack, reflecting less reserve and more comorbidity. The 3 points for age 75+ alone exceed most other single variables.
Is the score still valid in the PCI era?
For ranking patients by risk, yes; for absolute mortality percentages, it overestimates. Validation studies in PCI cohorts show good discrimination with lower observed mortality than the original table.
What is the maximum TIMI STEMI score?
14 points: 3 for age 75+, 3 for hypotension, 2 for tachycardia, 2 for Killip II-IV, and 1 each for low weight, risk history, anterior STE/LBBB, and delay. Scores above 8 were rare in the derivation cohort.
Who should use this calculator?
Clinicians, students, and those studying cardiology risk tools. It reproduces a published score for education. Real STEMI care is an emergency managed by a cardiac team; this page never substitutes for it.