TIMI risk score (UA/NSTEMI)
14-day risk of death, MI or urgent revascularisation in unstable angina / NSTEMI
- TIMI Study Group (derivation)
Sources last checked: 2026-10-13
TIMI risk score (UA/NSTEMI)
14-day risk of death, MI or urgent revascularisation in unstable angina / NSTEMI
4.7 % death, new/recurrent MI or severe recurrent ischaemia requiring urgent revascularisation at 14 days (TIMI 11B).
Event rates come from the heparin arm of the TIMI 11B trial (1990s, pre-high-sensitivity troponin) and overstate absolute risk under current care. The ESC 2023 ACS guideline prefers GRACE for risk-stratifying NSTE-ACS; TIMI is not a rule-out tool for undifferentiated chest pain.
Interpretation
| 0–1 | 4.7 % death, new/recurrent MI or severe recurrent ischaemia requiring urgent revascularisation at 14 days (TIMI 11B). |
|---|---|
| 2 | 8.3 % composite event rate at 14 days. |
| 3 | 13.2 % composite event rate at 14 days. |
| 4 | 19.9 % composite event rate at 14 days. |
| 5 | 26.2 % composite event rate at 14 days. |
| 6–7 | 40.9 % composite event rate at 14 days. |
What is the TIMI risk score (UA/NSTEMI)?
The TIMI risk score for unstable angina and NSTEMI sums seven bedside variables to estimate the 14-day risk of death, new or recurrent myocardial infarction, or severe recurrent ischaemia needing urgent revascularisation. Antman and colleagues derived it in 2000 from the TIMI 11B trial and validated it in ESSENCE. It also identified patients who gained most from more aggressive antithrombotic and invasive treatment.
When to use it
- Patients with an established diagnosis of unstable angina or NSTEMI, to communicate short-term risk.
- Reading literature and trials that stratify NSTE-ACS by TIMI score.
- Settings where GRACE inputs (e.g. creatinine, Killip class) are not yet available.
When not to use it
- STEMI — a separate TIMI score exists for STEMI.
- Undifferentiated chest pain in the emergency department, as a stand-alone discharge tool — use hs-troponin pathways and HEART.
- As the primary risk tool under ESC 2023, which recommends GRACE.
How it is calculated
| Criterion | Points |
|---|---|
| Age ≥ 65 years | +1 |
| ≥ 3 CAD risk factors (family history, hypertension, hypercholesterolaemia, diabetes, current smoking) | +1 |
| Known coronary stenosis ≥ 50 % | +1 |
| Aspirin use in the past 7 days | +1 |
| Severe angina: ≥ 2 episodes in the past 24 h | +1 |
| ST deviation ≥ 0.5 mm on the presenting ECG | +1 |
| Elevated cardiac markers (troponin / CK-MB) | +1 |
Clinical pearls and limitations
- Event rates come from the heparin arm of the TIMI 11B trial (1990s, pre-high-sensitivity troponin) and overstate absolute risk under current care. The ESC 2023 ACS guideline prefers GRACE for risk-stratifying NSTE-ACS; TIMI is not a rule-out tool for undifferentiated chest pain.
- All seven items score 1 point; the score is quick to apply at the bedside without a calculator.
- 'Aspirin in the past 7 days' marks a population that develops ACS despite antiplatelet therapy — a sign of more aggressive disease.
- Absolute event rates are from a 1990s trial population and are higher than in contemporary practice; use the score mainly for relative ranking.
Frequently asked questions
What does a TIMI score of 3 mean?
In the derivation cohort, a score of 3 corresponded to a 13.2 % risk of death, MI or urgent revascularisation within 14 days.
TIMI or GRACE — which should I use?
The ESC 2023 ACS guideline favours GRACE for risk stratification in NSTE-ACS because it discriminates better; TIMI remains widely used for its simplicity.
Which ECG change counts in the TIMI score?
ST deviation of at least 0.5 mm on the presenting ECG.
Can the TIMI score rule out ACS?
No. It was derived in patients who already had UA/NSTEMI, and a low score does not exclude ACS in undifferentiated chest pain.
Evidence and guidelines
- Primary source: Antman EM, Cohen M, Bernink PJLM et al. The TIMI risk score for unstable angina/non-ST elevation MI: a method for prognostication and therapeutic decision making. JAMA 2000;284(7):835-842.
- Byrne RA et al. 2023 ESC Guidelines for the management of acute coronary syndromes. Eur Heart J 2023;44:3720-3826.
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