Once a patient has been diagnosed with unstable angina or a non-ST-elevation myocardial infarction (UA/NSTEMI), the next question is no longer “is this a heart attack?” — it’s “how aggressively should we treat it, and how fast?” Some patients do best with an early trip to the catheterization lab; others do just as well with medical management and a more conservative pace. The TIMI Risk Score was built to help make that call with a number instead of a gut feeling alone, and more than two decades after its 2000 publication in JAMA, it is still one of the most widely used tools for that decision.
Where TIMI fits in the timeline
It’s worth being precise about when TIMI applies, because this is also where it is most often misused. The TIMI Risk Score described here was derived and validated in the TIMI 11B trial specifically for patients who already have a diagnosis of unstable angina or NSTEMI — it comes after the diagnostic work-up, not instead of it. It has nothing to do with deciding whether a patient is having a heart attack in the first place, and it should never be reached for in a patient with ST-elevation myocardial infarction (STEMI), where the priority is immediate reperfusion therapy regardless of any score.
The seven yes/no questions
TIMI asks seven questions, each worth one point: is the patient 65 or older; do they have three or more standard risk factors for coronary artery disease (family history, hypertension, high cholesterol, diabetes, or current smoking); do they have known coronary artery disease, meaning a prior stenosis of 50 percent or more; have they taken aspirin in the past seven days; have they had severe angina, meaning two or more episodes in the preceding 24 hours; does their presenting ECG show ST-segment changes of at least 0.5mm; and is their initial cardiac biomarker elevated. Seven questions, seven possible points, all answerable from information a clinician already has as part of a standard UA/NSTEMI work-up.
What the score actually changes
The risk of death, myocardial infarction, or urgent revascularization within 14 days climbs steadily with the score: roughly 5 percent at 0 or 1 point, about 8 percent at 2, around 13 percent at 3, roughly 20 percent at 4, about 26 percent at 5, and around 41 percent at 6 or 7. A score of 3 or higher is the threshold most commonly used to favor an early invasive strategy — prompt catheterization, with revascularization if indicated — over an initial conservative approach built around medical therapy and watchful waiting. Below that threshold, a conservative strategy guided by clinical judgment is generally reasonable.
A note on the other TIMI score
There is a second, differently-weighted TIMI risk score built for STEMI patients, derived separately from the InTIME-II trial population. It is easy to conflate the two because they share a name, but they answer different questions for different patients at different points in the pathway. The seven-item score covered here, and implemented in the calculator below, is the UA/NSTEMI version from TIMI 11B — if the patient in front of you has a STEMI, this is not the tool to reach for.
Clinical decision-support aid, not a substitute for clinical judgment: the TIMI Risk Score implements a published scoring rule for education and workflow support. It is not a medical device and has not been reviewed by the FDA or any regulatory body — every result should be interpreted by a qualified clinician alongside the full clinical picture.
Editverse’s free TIMI Risk Score Calculator walks through all seven criteria with a live worked example, a plain-language readout, and a citation you can drop straight into a manuscript methods section.
Reference: Antman EM, Cohen M, Bernink PJ, et al. JAMA. 2000;284(7):835–842.
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