TIMI Risk Score for STEMI

How to Use This Calculator

1. Select each of the 8 STEMI TIMI variables from the dropdowns.
2. TIMI STEMI score and 30-day mortality update instantly.
3. Use the 30-Day Mortality Table tab for the complete score-to-mortality reference.
4. Note: this is the STEMI version — different from UA/NSTEMI TIMI.

Formula

Example

Frequently Asked Questions

• How is STEMI TIMI different from UA/NSTEMI TIMI? ▼
  The TIMI risk scores for STEMI and UA/NSTEMI are completely different tools that share only the "TIMI" name and the binary scoring concept. The TIMI risk score for STEMI was derived by Morrow et al. from the InTIME II trial and published in Circulation in 2000. It uses eight variables with differential weighting: age 65-74 (2 points), age ≥75 (3 points), diabetes/hypertension/angina history (1 point), systolic BP < 100 mmHg (3 points), heart rate > 100 bpm (2 points), Killip class II-IV (2 points), body weight < 67 kg (1 point), anterior ST-elevation or LBBB (1 point), and time to treatment > 4 hours (1 point). The maximum score is approximately 14 points, and the outcome predicted is 30-day all-cause mortality, not 14-day MACE as in the NSTEMI version. The UA/NSTEMI TIMI uses 7 binary variables (all weighted equally at 1 point each) for a maximum score of 7, predicting 14-day MACE. These differences are clinically critical: applying the STEMI scoring system to an NSTEMI patient (or vice versa) will produce meaningless results. The STEMI version is used at the time of STEMI presentation to estimate 30-day mortality and guide intensity of care.
• What does a high TIMI STEMI score predict? ▼
  The TIMI STEMI score provides quantitative 30-day mortality estimates based on derivation data from the InTIME II trial. A score of 0 carries approximately 0.8% 30-day mortality — the lowest risk group. The mortality increases steeply with rising scores: score 3 is 4.4%, score 5 is 12.4%, score 6 is 16.1%, score 7 is 23.4%, score 8 is 26.8%, and scores of 9 or higher correspond to approximately 35.9% 30-day mortality. These estimates represent the pre-primary PCI era and are thus somewhat higher than contemporary STEMI mortality, which has decreased significantly with universal primary PCI availability, potent antiplatelet therapy (ticagrelor/prasugrel), and optimized post-MI care. However, the rank ordering of risk remains valid, and the score still effectively identifies patients at highest risk who should be treated most aggressively with shortest door-to-balloon times, most potent antithrombotic regimens, and early ICU/CCU admission. High-scoring patients should also trigger early discussion about mechanical circulatory support (e.g., intra-aortic balloon pump, Impella) in cardiogenic shock.
• Should patients with high TIMI STEMI scores get more aggressive treatment? ▼
  Yes, in multiple dimensions. The TIMI STEMI score helps prioritize resource allocation and treatment intensity for patients with acute STEMI in a busy emergency or catheterization laboratory. High TIMI STEMI scores (≥6) identify patients who: benefit most from the shortest possible door-to-balloon times — every 30-minute reduction in time-to-PCI is associated with approximately 7.5% relative reduction in mortality; should receive the most potent antiplatelet regimens (ticagrelor 180 mg loading dose or prasugrel 60 mg, rather than clopidogrel, per ESC 2023 STEMI guidelines and PLATO/TRITON-TIMI 38 trial data); require intensive hemodynamic monitoring in the coronary care unit; should undergo evaluation for mechanical circulatory support if cardiogenic shock develops; and may benefit from complete revascularization of non-culprit vessels during the index hospitalization (supported by the COMPLETE and FLOWER-MI trials). However, it is important to note that primary PCI is the recommended treatment for ALL STEMI patients when available within 120 minutes of first medical contact — the TIMI score modifies the intensity of the care pathway, not the fundamental decision to proceed with primary PCI.
• How does time-to-PCI affect TIMI STEMI mortality estimates? ▼
  Time to reperfusion is one of the eight TIMI STEMI variables: time to treatment > 4 hours adds 1 point to the score. This reflects a well-established biological principle: the longer coronary artery occlusion persists, the greater the extent of myocardial necrosis and the higher the mortality risk. The seminal analysis by De Luca et al. (Circulation 2004) of over 27,000 STEMI patients showed that each 30-minute delay in door-to-balloon time was associated with a 7.5% relative increase in 1-year mortality. This translates to meaningful absolute differences: a patient with a 90-minute door-to-balloon time has approximately 3% 1-year mortality vs approximately 4.2% at 3 hours. The TIMI score's time variable is a binary 4-hour threshold, but the actual relationship is continuous — earlier is always better. Modern STEMI systems of care aim for door-to-balloon times < 90 minutes (from hospital arrival) or first-medical-contact-to-balloon < 120 minutes. Pre-hospital ECG transmission and catheterization laboratory activation prior to hospital arrival can reduce total ischemic time by 30-45 minutes, translating directly into lives saved for high TIMI STEMI score patients.
• What is the difference between the TIMI STEMI and CADILLAC scores? ▼
  The TIMI STEMI and CADILLAC scores both predict STEMI outcomes, but they are designed for different time points in the clinical course. The TIMI STEMI score is a pre-treatment admission risk score — it uses variables available at the time of presentation (before PCI), making it useful for initial triage and treatment planning. The CADILLAC (Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications) score was derived from the CADILLAC trial and predicts 30-day mortality after primary PCI — it is a post-procedure risk score. CADILLAC uses six variables: LVEF < 40% (measured by angiography or ventriculography during PCI), renal impairment (creatinine > 1.5 mg/dL), TIMI flow grade 0-2 after PCI (suboptimal reperfusion), Killip class ≥2, age ≥65, and anemia (hemoglobin < 12 g/dL). Because CADILLAC incorporates post-PCI TIMI flow and LVEF — both only available after the intervention — it cannot be used for pre-procedure triage. It is superior to TIMI STEMI for post-PCI risk stratification and discharge planning. In clinical practice, TIMI STEMI is used at admission to guide treatment urgency, while CADILLAC may be applied post-PCI to plan the intensity of post-MI monitoring and therapy.

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