Risk stratification in acute coronary syndromes - does the TIMI risk score work in unselected cases?

Background: Management of patients with an acute coronary syndrome (ACS) requires accurate risk stratification to guide appropriate therapy.

Aim: To assess the utility of the TIMI risk score in stratifying patients with possible ACS in routine clinical practice.

Design: Prospective observational study.

Methods: We recruited 869 consecutive patients with a diagnosis of possible ACS attending the acute medical receiving unit of a district general hospital. The main outcome measures were recurrent myocardial infarction, urgent revascularization, and all-cause mortality. TIMI risk score was calculated for each patient, and each was also assigned a risk group based on electrocardiogram (ECG) changes and troponin levels only. After follow-up, Cox univariate and multivariate regression was used to evaluate the influence of potential risk factors on duration of event-free survival, and likelihood ratio tests to assess the fit of the models.

Results: Increasing TIMI risk score was associated with increased risk of events (p < 0.001), as was higher risk group from ECG plus troponin stratification (p < 0.001). The likelihood ratio comparison favoured the TIMI risk score (difference 13.910, 5 degrees of freedom, p = 0.016).

Discussion: The TIMI risk score is a valid tool for risk stratification in unselected cases with possible acute coronary syndrome. It is superior to ECG changes and troponin alone, although this simpler method also achieves good risk stratification.