Calculate the TIMI risk score for ST-elevation myocardial infarction. Predicts 30-day mortality using 8 clinical variables from the InTIME-II trial.
The TIMI Risk Score for STEMI (ST-Elevation Myocardial Infarction) is a bedside clinical tool developed from the 15,000-patient InTIME-II trial by Morrow et al. (2000). It uses 8 readily available variables to predict 30-day all-cause mortality in patients presenting with acute STEMI who are receiving fibrinolytic therapy.
The score incorporates age, comorbidities (diabetes, hypertension, angina), hemodynamic status (blood pressure, heart rate), Killip class, body weight, ECG findings (anterior ST elevation or LBBB), and time to treatment. Total scores range from 0 to 14, with 30-day mortality increasing from 0.8% (score 0) to >35% (score ≥8) in a graded fashion.
While originally validated for fibrinolytic-treated patients, the TIMI STEMI score has been applied in primary percutaneous coronary intervention (PCI) populations and remains one of the most widely used prognostic tools for acute STEMI risk stratification. Check the example with realistic values before reporting. Use the steps shown to verify rounding and units. Cross-check this output using a known reference case.
Acute STEMI carries significant short-term mortality, but the risk varies enormously — from <1% to >35% — depending on patient characteristics and presentation. The TIMI STEMI score identifies high-risk patients who may benefit from more aggressive reperfusion strategies (immediate transfer for PCI rather than fibrinolysis), closer hemodynamic monitoring, mechanical circulatory support, and earlier goals-of-care discussions.
For low-risk patients, the score supports early discharge pathways and outpatient follow-up planning, optimizing resource utilization.
TIMI STEMI Score (0-14): Age 65-74: 2 pts | Age ≥75: 3 pts DM, HTN, or angina (any): 1 pt SBP <100 mmHg: 3 pts HR >100 bpm: 2 pts Killip II-IV: 2-4 pts Weight <67 kg: 1 pt Anterior STE or LBBB: 1 pt Time to treatment >4h: 1 pt
Result: TIMI STEMI Score 10 — 30-Day Mortality ~35.9%
Age 70 (2 pts) + DM/HTN (1 pt) + SBP <100 (3 pts) + HR >100 (2 pts) + Killip II (2 pts) + Anterior STE (1 pt) = 11 points. Very high risk. This patient should receive immediate primary PCI, aggressive hemodynamic support, and intra-aortic balloon pump or mechanical support consideration.
Low risk (TIMI 0-3): Primary PCI preferred; fibrinolysis acceptable if PCI not available within 120 minutes. Moderate risk (TIMI 4-6): Primary PCI strongly preferred; consider transfer to PCI-capable center. High risk (TIMI ≥7): Primary PCI mandated; consider mechanical circulatory support (IABP, Impella); early hemodynamic monitoring.
Killip I: No clinical signs of heart failure (mortality ~6%). Killip II: Pulmonary rales in lower half of lung fields, S3 gallop, elevated JVP (mortality ~17%). Killip III: Frank pulmonary edema (mortality ~38%). Killip IV: Cardiogenic shock — hypotension, oliguria, cyanosis (mortality ~67% without intervention, ~40-50% with emergent revascularization and support).
Beyond the acute TIMI score, long-term risk assessment includes: LVEF <40% (heart failure risk), residual ischemia on stress testing, persistent arrhythmias, incomplete revascularization, and biomarker trajectories (troponin peak, BNP). These factors guide decisions about ICD placement, cardiac rehabilitation intensity, and medication optimization.
The score was derived from fibrinolytic-treated patients (InTIME-II, 2000), but subsequent studies have validated its prognostic ability in patients undergoing primary PCI. The absolute mortality rates may be lower in the PCI era, but the relative risk stratification remains accurate — higher scores consistently predict worse outcomes regardless of reperfusion strategy.
The TIMI STEMI score predicts 30-day mortality in STEMI patients using different variables than the TIMI UA/NSTEMI score, which predicts 14-day events (death, MI, urgent revascularization) in unstable angina and NSTEMI. They are distinct scores for different clinical scenarios and should not be used interchangeably.
Killip classification is the strongest individual component of the TIMI STEMI score. Killip I (no heart failure) = 0 pts, Killip II (rales, JVD) = 2 pts, Killip III (pulmonary edema) = 3 pts, Killip IV (cardiogenic shock) = 4 pts. Cardiogenic shock alone contributes nearly 30% of the maximum score, reflecting its devastating impact on mortality.
Lower body weight in STEMI patients is associated with higher mortality, possibly due to: (1) relative overdosing of medications, (2) lesser physiological reserve, (3) association with frailty and comorbid conditions, and (4) correlation with older age and female sex. The 67 kg cutoff was statistically derived from the InTIME-II cohort.
The GRACE (Global Registry of Acute Coronary Events) score is another widely used ACS prognostic tool that predicts in-hospital and 6-month mortality for the full ACS spectrum. GRACE uses more variables (8 including creatinine and cardiac arrest) and is considered more discriminant by some guidelines. Both scores are recommended by ACC/AHA for risk stratification.
Time to reperfusion is one of the most critical modifiable factors in STEMI outcomes. Every 30 minutes of delay increases mortality by approximately 7.5%. The TIMI score accounts for >4 hours delay (1 pt), but the clinical mandate is "door-to-balloon <90 minutes" for PCI or "door-to-needle <30 minutes" for fibrinolytics, regardless of the score.