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Primary source: Antman EM, Cohen M, Bernink PJLM, et al. The TIMI Risk Score for Unstable Angina/Non–ST Elevation MI.
JAMA. 2000;284(7):835–842. PMID:
10938172.
Original derivation cohort: TIMI 11B trial + ESSENCE trial (n=1,957). Validated in TIMI 11B and ESSENCE independently. Risk percentages from Table 4 of Antman 2000.
Applies to UA and NSTEMI only — not STEMI.
Clinical judgment always takes precedence.
Clinical decision support only. TIMI score guides risk stratification — it does not replace clinical assessment or local ED protocols. All chest pain presentations require clinical judgment and appropriate ECG/biomarker interpretation. Antman et al., JAMA 2000
Score each variable — 1 point each
✓
≥3 coronary artery disease risk factors
Family history of CAD · hypertension · hypercholesterolaemia · diabetes · active smoker
+1
✓
Prior coronary stenosis ≥50%
Known significant coronary artery disease on prior angiography or revascularisation
+1
✓
ST deviation on presenting ECG
ST depression or transient ST elevation ≥0.5 mm on admission ECG
+1
✓
≥2 anginal events in prior 24 hours
Two or more episodes of angina in the 24 hours prior to presentation
+1
✓
Aspirin use in prior 7 days
Patient was taking aspirin in the 7 days preceding presentation (suggests aspirin-refractory angina)
+1
✓
Elevated serum cardiac markers
Raised troponin (I or T) or CK-MB at presentation
+1
14-day risk by score
Composite endpoint: all-cause mortality, new/recurrent MI, or urgent revascularisation. Antman et al., JAMA 2000 (n=1,957)
| Score | Risk category | 14-day event rate |
|---|
| 0–1 | Very low | 4.7% |
| 2 | Low | 8.3% |
| 3 | Intermediate | 13.2% |
| 4 | Intermediate | 19.9% |
| 5 | High | 26.2% |
| 6–7 | Very high | 40.9% |
Clinical context
Who the TIMI score applies to: Patients presenting with ischaemic symptoms at rest or with minimal exertion with either ST changes on ECG or elevated cardiac biomarkers — i.e., those in whom UA/NSTEMI is being considered. It is not validated for STEMI (use TIMI for STEMI) or stable angina.
How to use the score in practice: Score 0–2 supports a lower-risk pathway, while score ≥3 generally warrants cardiology discussion and expedited investigation. Score ≥5 is high-risk and typically requires hospital admission and early invasive strategy. Always apply in conjunction with serial troponins, ECG evolution, and clinical judgment. Antman et al., JAMA 2000 · AHA/ACC UA/NSTEMI Guidelines
Variable 3 — prior stenosis ≥50%: If coronary anatomy is unknown, score this variable as present if the patient has known CAD (prior MI, prior PCI/CABG). If truly no prior cardiac history, score as absent.
Variable 6 — aspirin in prior 7 days: This variable identifies aspirin-refractory presentations, which carry a higher risk independent of other factors.
Limitations: The TIMI score was derived and validated in clinical trial populations (TIMI 11B, ESSENCE). It may underestimate risk in women, elderly patients, and those with renal impairment. Local protocol and clinical judgment always supersede risk score alone. Antman et al., JAMA 2000