About the TIMI Risk Score Calculator
The TIMI risk score for unstable angina and non-ST-elevation myocardial infarction (UA/NSTEMI) was developed by Antman and colleagues from the TIMI 11B and ESSENCE trials and published in JAMA in 2000. It adds one point for each of seven predictors available at presentation, giving a score from 0 to 7.
The predictors are: age 65 or older; at least three risk factors for coronary artery disease (family history, hypertension, high cholesterol, diabetes, current smoking); known coronary stenosis of 50% or more; aspirin use in the previous 7 days; at least two episodes of angina in the last 24 hours; ST-segment deviation of 0.5 mm or more on the presenting ECG; and raised cardiac biomarkers. In the derivation cohort, the 14-day rate of death, new or recurrent MI, or severe recurrent ischaemia requiring urgent revascularisation rose from 4.7% at a score of 0–1 to 40.9% at 6–7.
The score was derived in patients with confirmed UA/NSTEMI enrolled in clinical trials, and is used by cardiologists, emergency clinicians and students to stratify risk. It is not designed to diagnose acute coronary syndrome in undifferentiated chest pain, and does not apply to ST-elevation MI, which has its own TIMI score.
With the default inputs, the timi risk score is 3 / 7. Change any value above to recalculate instantly.
How to use the timi risk score calculator
- 1Use this for a patient with confirmed unstable angina or NSTEMI.
- 2Tick age 65 or older and three or more coronary risk factors if present.
- 3Tick known coronary stenosis ≥ 50% and aspirin use in the last week.
- 4Tick recent recurrent angina, ST deviation and raised biomarkers.
- 5Read the score and the 14-day event rate from the original trial.
Formula and method
The seven predictors were selected by multivariable logistic regression in the unfractionated-heparin arm of TIMI 11B (1,957 patients) and each was given equal weight of one point. Event rates through 14 days in that cohort were 4.7% (score 0–1), 8.3% (2), 13.2% (3), 19.9% (4), 26.2% (5) and 40.9% (6–7), and the same gradient was confirmed in three validation cohorts.
The low (0–2), intermediate (3–4) and high (5–7) groupings shown here are a common convention for summarising the score; the published event rates by individual score are more informative.
- CAD
- Coronary artery disease
- ST deviation
- ST depression or transient ST elevation ≥ 0.5 mm
Worked examples
Older patient on aspirin with ST depression
Age ≥ 65, aspirin in the past week and ST deviation give 3 points. In TIMI 11B, 13.2% of patients with a score of 3 had an event by 14 days.
Younger patient with a single factor
Only the raised troponin scores, giving 1 point. Scores of 0 and 1 were grouped together with a 4.7% 14-day event rate.
High-risk NSTEMI
All seven predictors are present for the maximum score of 7, in the 6–7 group with a 40.9% event rate at 14 days.
Frequently asked questions
What does the TIMI risk score predict?+
The combined risk, within 14 days, of all-cause death, new or recurrent myocardial infarction, or severe recurrent ischaemia requiring urgent revascularisation in patients with unstable angina or NSTEMI.
Which CAD risk factors count toward the three?+
Family history of coronary artery disease, hypertension, hypercholesterolaemia, diabetes and current smoking. At least three must be present to earn the point.
Why does aspirin use increase the score?+
Having an acute coronary syndrome despite taking aspirin in the last 7 days suggests more aggressive disease or aspirin resistance, and it was an independent predictor of events in the derivation trial.
Can the TIMI score be used for chest pain in the emergency department?+
It has been studied in undifferentiated chest pain, but it was designed for confirmed UA/NSTEMI. For ED chest pain, scores such as HEART are usually preferred for identifying low-risk patients.
What is the difference between the TIMI and GRACE scores?+
TIMI is a simple 7-point additive score. GRACE uses continuous variables such as age, heart rate, blood pressure, creatinine and Killip class, and generally discriminates risk better but needs a calculator.
For healthcare professionals and education only. This calculator implements a published formula or score but is not a diagnosis and does not replace clinical judgment. Verify inputs and results against the original source before using them in patient care.