EBM Consult

TIMI Risk Score for Unstable Angina or Non-ST Elevation MI (NSTEMI)


The TIMI risk score is an easy bedside calculation mostly based on the patient's medical history and a few initial tests (ECG and initial labs) in patients presenting to the emergency department (ED) with unstable angina or NSTEMI when trying to assess their risk for cardiac related ischemic events and death within the first 14 days after presenting to the ED.

  • TIMI Risk Scores of 0 - 1 have a 4.7% risk
  • TIMI Risk Scores of 6 - 7 have a 40.9% risk
  • All groups showed an increase in event rates with higher TIMI risk scores
  • Patients with higher TIMI risk scores also had better outcomes if treated with enoxaparin versus unfractionated heparin
  • Note: 
    • It is worth pointing out that even patients with the lowest TIMI risk score (0 - 1) are still at concerning risk within the first 14 days of presentation.  This highlights the importance of further admission and testing, or very close follow up. 
    • The 2014 AHA/ACC Guidelines for NSTEMI say that risk scores should be used to assess the prognosis in patients and give this a Class IA, Level of Evidence A recommendation

    Anthony J. Busti, MD, PharmD, FNLA, FAHA
Dylan Kellogg, MD
Date Last Reviewed:
September 2015

Supporting Guidelines

  • 2014 ACC/AHA NSTEMI Guidelines:
    "Risk scores should be used to assess prognosis in patients with NSTE-ACS."

    • Guideline Rating:  Class Ia, Level of Evidence: A
    • Reference: Amsterdam EA et al.  2014 AHA/ACC Guideline for the Management of Patients With Non-ST-Elevation Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines.  Circulation 2014:[Epub ahead of print].  PubMed

Landmark or Original Studies

  • Antman EM et al. The TIMI risk score for unstable angina/non-ST elevation MI: A method for prognostication and therapeutic decision making. JAMA 2000;284(7):835-42. PubMed
    LOE 1b
    Study Design Analysis of two Phase 3, International, Randomized, Double-Blind trials (TIMI 11B and ESSENCE)
    Sample Size
    • N = 1957 patients with UA/NSTEMI were assigned to receive unfractionated heparin (test cohort) and 1953 to receive enoxaparin in TIMI 11B trial
    • N = 1564 and 1607 were assigned respectively in ESSENCE trial
    Population Adults with unstable angina or NSTEMI
    Primary Endpoint To develop a simple risk score that has broad applicability, is easily calculated at patient presentation, does not require a computer, and identifies patients with different responses to treatments for UA/NSTEMI.
    • The 7 TIMI risk score predictor variables were: age ≥ 65, at least 3 risk factors for CAD, prior coronary stenosis of ≥50%, ST-segment deviation on ECG at presentation, at least 2 anginal events in prior 24 hours, use of aspirin in prior 7 days, and elevated serum cardiac markers.
    • Event rates increased as the TIMI risk score increased 4.7% for a score of 0/1, 8.3% for a score of 2, 13. 2% for a score of 3, 19.9% for a score of 4, 26.2% for a score of 5, 40.9% for a score of 6/7.
    • The pattern of increasing event rates with increasing TIMI risk score was confirmed in all 3 validation groups (P<.001).
    • The event rates was significantly lower in the enoxaparin groups in both TIMI 11B (P =.01) and ESSENCE (P =.03).
    Conclusion The TIMI risk score is a simple prognostication scheme that categorizes a patient's risk of death and ischemic events and provides a basis for therapeutic decision making.

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MESH Terms or Keywords

  • TIMI Risk Score, TIMI Risk Score for Unstable Angina, TIMI Risk Score NSTEMI