A Population-Based Evaluation of the Thrombolysis in Myocardial Infarction Risk Score for Unstable Angina and Non-ST Elevation Myocardial Infarction

Abstract

Background: The Thrombolysis in Myocardial Infarction risk score (TIMI-RS) for unstable angina/non-ST elevation myocardial infarction (MI) was developed in patients presenting with unstable angina accompanied by high-risk features or non-ST elevation MI to determine early risk stratification. Hypothesis: The validity in patients presenting for emergency care with symptoms suggestive of acute coronary syndrome (ACS) has not been well established, and the present study sought to do so by evaluating the TIMI-RS in a prospective fashion. Methods: A prospective TIMI-RS using seven variables was calculated in 245 patients admitted to the hospital with symptoms suggestive of ACS: (1) age > 65, (2) three or more cardiac risk factors, (3) ST deviation, (4) aspirin use within 7 days, (5) two or more anginal events over 24 h, (6) history of coronary stenosis, and (7) elevated troponin. Patients were contacted at 30 days and data were collected concerning major adverse cardiac events. Results: In patients presenting with chest pain, a higher TIMI-RS was associated with an increase in major adverse cardiac events within 30 days. We found that the 30-day event rate was 0% for a score of 1, 20% for a score of 2, 24% for a score of 3, 42% for a score of 4, 52% for a score of 5, and 70% for a score of 6 or 7 (p < 0.0001). Conclusions: The TIMI-RS successfully differentiates early risk for major adverse cardiac events in a general population presenting with symptoms suggestive of acute coronary syndrome. A simple bedside calculation of the TIMI-RS provides rapid risk stratification, allowing facilitation of therapeutic decision making in patients with symptoms suggestive of ACS.