Risk prediction in patients presenting with suspected cardiac pain: the GRACE and TIMI risk scores versus clinical evaluation

Abstract

BACKGROUND: Identifying which patients presenting with undifferentiated chest pain are at risk of major cardiac events is a major clinical challenge. Clinical evaluation may lack sufficient precision, leading to unnecessary admission or inappropriate discharge. It is uncertain whether risk scores derived from ACS populations apply to unselected patients with chest pain. AIM: To determine the predictive accuracies of the GRACE risk score, the TIMI risk score and clinical evaluation in unselected patients with suspected cardiac pain. DESIGN: Prospective observational study. METHODS: We recruited 347 sequential patients with suspected cardiac pain presenting to a large teaching hospital. The main outcome measures were death, non-fatal myocardial infarction and emergency revascularization, in hospital and at 3 months. Receiver operating characteristic (ROC) curves were plotted for TIMI and GRACE risk scores and clinical evaluation. RESULTS: Overall 54 patients (15.6%) experienced a major cardiac event (16 deaths, seven myocardial infarctions (MIs), one emergency revascularization) or emergency re-admission (n=30) within 3 months. Both GRACE (p<0.001) and TIMI scores (p<0.001) predicted death/MI/revascularization (and the composite including re-admission), but the GRACE score was superior to the TIMI score for predicting major cardiac events (z=2.05), and both scores were superior to clinical evaluation (ROC areas 0.82, 0.74 and 0.55 respectively). The GRACE score predicted an ACS discharge diagnosis (p<0.001) and duration of hospital stay (p<0.001). DISCUSSION: In unselected patients presenting with suspected cardiac pain, the GRACE risk score is superior to the TIMI risk score in predicting major cardiac events, and both risk scores are superior to using ECG and troponin findings at presentation.