Thrombolysis in myocardial infarction (TIMI) risk score

The thrombolysis in myocardial infarction (TIMI) risk score is a prognostic risk stratification system that categorizes the risk of death and ischemic events in patients with unstable angina / non-ST elevation myocardial infarction and provides a basis for therapeutic decision making. It is thought to have potential to improve the management of patients presenting to hospital with undifferentiated chest pain where ischemic heart disease is a potential diagnosis ³.

Score calculation

One point is given for each:

• age ≥65 years
• aspirin use within the last 7 days (patient has chest pain despite as required use in past 7 days)
• at least 2 angina episodes in the last 24 hours
• ST changes of at least 0.5 mm in contiguous leads
• elevated serum cardiac biomarkers
• known coronary artery disease (CAD) (coronary stenosis ≥50%)
• at least 3 risk factors for coronary artery disease, which include:
  • hypertension >140/90 mmHg or on anti-hypertensives
  • current cigarette smoking 
  • low HDL cholesterol (<40 mg/dL)
  • diabetes mellitus
  • family history of premature coronary artery disease
    • male first-degree relative or father younger than 55 years
    • female first-degree relative or mother younger than 65 years

Score interpretation

A percentage risk at 14 days of all-cause mortality, new or recurrent myocardial infarction, or severe recurrent ischemia requiring urgent revascularization.

The predicted risk is as follows ⁴:

• score of 0-1 = 4.7% risk
• score of 2 = 8.3% risk
• score of 3 = 13.2% risk
• score of 4 = 19.9% risk
• score of 5 = 26.2% risk
• score of 6-7 = at least 40.9% risk

See also

• GRACE risk score
• PURSUIT risk score
• FRISK risk score