TIMI Risk Score for STEMI Calculator

Enter Calculation

Age Under 65 (0 points) 65 to 74 (2 points) 75 or older (3 points)

History of diabetes, hypertension, or angina (1 point)

Systolic blood pressure < 100 mmHg (3 points)

Heart rate > 100 bpm (2 points)

Killip class II to IV (2 points)

Weight < 67 kg (1 point)

Anterior ST elevation or LBBB (1 point)

Time to treatment > 4 hours (1 point)

Formula

Results

TIMI Risk Score (STEMI)

0

points (range 0–14)

Estimated 30-day mortality	0.8%

What is the TIMI Risk Score for STEMI?

The TIMI (Thrombolysis In Myocardial Infarction) Risk Score for STEMI is a validated bedside tool used to estimate 30-day mortality in patients presenting with ST-elevation myocardial infarction. Derived from the InTIME II trial population, it converts eight readily available clinical variables into a single integer score from 0 to 14, where a higher score indicates greater risk. It helps clinicians stratify risk quickly and guide the intensity of treatment and monitoring.

How to use it

Select the patient's age band and check each risk factor that applies at presentation: a history of diabetes, hypertension, or angina; systolic blood pressure below 100 mmHg; heart rate above 100 bpm; Killip class II–IV; body weight under 67 kg; anterior ST elevation or new left bundle branch block; and time to treatment greater than 4 hours. The calculator sums the assigned points and maps the total to an approximate 30-day mortality estimate.

The formula explained

Each factor carries a fixed weight reflecting its prognostic strength. Age contributes the most graded weight (2 points for 65–74 years, 3 points for 75 and older), while hypotension (SBP < 100) also adds 3 points. Tachycardia and Killip class each add 2 points, and the remaining factors add 1 point each. The score is simply the arithmetic sum of all qualifying weights.

$$\text{Score} = \text{Age} + \text{Hx} + \text{SBP} + \text{HR} + \text{Killip} + \text{Wt} + \text{Ant} + \text{Time}$$

$$\text{Score} = \sum \text{weighted risk factors}$$

The eight clinical risk factors summed to give the TIMI STEMI score.

Worked example

Consider a 70-year-old patient (2 points) with a history of hypertension (1 point), heart rate 110 bpm (2 points), and anterior ST elevation (1 point). Total = $$2 + 1 + 2 + 1 = 6$$ points, corresponding to an estimated 30-day mortality of roughly 16%.

Estimated 30-day mortality increases with higher total TIMI scores.

FAQ

Is this score only for STEMI? Yes. A separate TIMI score exists for unstable angina and NSTEMI; this calculator applies specifically to ST-elevation MI.

What is the maximum score? The theoretical maximum is 14 points when every weighted criterion is met.

Does this replace clinical judgment? No. The score is a risk-stratification aid and should be interpreted alongside the full clinical picture, not used in isolation.