Cardiology
TIMI Risk Score (UA/NSTEMI)
14-day risk of adverse events in unstable angina/NSTEMI.
Education and reference only. Not a substitute for clinical judgement, local policy or product labelling. Always verify before clinical use. Values are calculated in your browser and never stored.
Background
The TIMI risk score for unstable angina/NSTEMI estimates the 14-day risk of death, new or recurrent myocardial infarction, or severe recurrent ischaemia requiring urgent revascularisation. It was derived from the TIMI 11B and ESSENCE anticoagulation trials to help guide the intensity of early treatment. Seven equally weighted variables each score one point: age ≥65, three or more coronary risk factors, known coronary stenosis ≥50%, aspirin use in the prior week, two or more anginal episodes in 24 hours, ST-segment deviation ≥0.5 mm and a raised cardiac biomarker. The total ranges from 0 to 7.
Interpreting the result
Event risk rises steadily with the score, from a low single-digit percentage at 0–1 to over 40% at 6–7. In practical bands, 0–2 is low risk, 3–4 intermediate and 5–7 high risk. A higher score supports an early invasive strategy with prompt coronary angiography, whereas low scores may allow a more conservative, ischaemia-guided approach. The score complements rather than replaces troponin trends, ECG findings and haemodynamic assessment.
Worked example
A 70-year-old smoker with hypertension and diabetes presents with two episodes of chest pain, ST depression on the ECG and a raised troponin: age ≥65 (1) + ≥3 risk factors (1) + ≥2 angina episodes (1) + ST deviation (1) + positive biomarker (1) = 5, a high-risk score favouring an early invasive strategy.
Pearls / pitfalls
- The score applies to unstable angina/NSTEMI, not to ST-elevation MI, which has its own pathway and a separate TIMI STEMI score.
- GRACE generally discriminates better for mortality and is preferred in several guidelines; TIMI is valued for its simplicity at the bedside.
- Prior aspirin use paradoxically adds a point because it identifies a more refractory, higher-risk population.
- A low score does not exclude significant coronary disease — serial troponins and clinical judgement remain essential.
Evidence & validation
Derived and validated by Antman et al. (2000) using TIMI 11B and ESSENCE data and reproduced in many cohorts; it is referenced by ESC and ACC/AHA guidance among the risk tools for NSTE-ACS, alongside the more discriminating GRACE score.
Frequently asked questions
What does the TIMI score predict?
It predicts the 14-day composite risk of death, myocardial infarction, or severe recurrent ischaemia needing urgent revascularisation in unstable angina/NSTEMI. It is used to gauge how aggressively to investigate and treat.
How does TIMI compare with GRACE?
GRACE uses continuous variables and generally predicts mortality more accurately, and is preferred in several guidelines. TIMI is simpler and quicker at the bedside but less discriminating.
Why does taking aspirin add a point?
Recent aspirin use identifies patients who developed an event despite antiplatelet therapy, marking a more treatment-resistant, higher-risk group. It is counter-intuitive but reflects the derivation data.
Can I use this score for a STEMI?
No — this score is for unstable angina and NSTEMI. ST-elevation MI follows a separate reperfusion pathway and has its own dedicated TIMI score.
Does a high score mean angiography is mandatory?
A high score supports an early invasive strategy, but the decision also weighs comorbidity, bleeding risk and patient preference. The score informs rather than dictates management.
References
- 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.
- Collet JP, Thiele H, Barbato E, et al. 2020 ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation. Eur Heart J. 2021.
About the creator
Antman EM et al.
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