Comparison of cardiac risk scores in ED patients with potential acute coronary syndrome

Objective: The ability to risk stratify patients presenting to the emergency department (ED) with potential acute coronary syndrome (ACS) is critical. Several risk scores for patients with definite ACS have been developed, but only the TIMI risk score has been shown to risk stratify ED patients with potential ACS. We compared the prognostic value of the GRACE and PURSUIT risk scores to the TIMI score in the broader ED patient population presenting with potential ACS. Methods: We performed a secondary analysis of a prospective cohort study that enrolled patients who presented to the ED with potential ACS. Demographics, history, and components of the TIMI, GRACE, and PURSUIT scores were obtained. Follow-up was conducted by structured record review and phone. The main outcome was a composite of 30-day death, nonfatal acute myocardial infarction, and revascularization. The GRACE scores ranged from 0 to 330 and PURSUIT scores ranged from 0 to 18 and were subsequently divided into 8 equivalent strata to correspond with TIMI score range and to facilitate comparison. For each of the 3 risk scores, receiver operating characteristic (ROC) curves were used to compare prediction of 30-day event rates. Results: There were 4743 patients enrolled (mean age: 52.5 ± 13.3; 56% female; 65% black). By 30 days, there were 59 deaths, 172 acute myocardial infarctions, and 175 revascularizations. The area under the curve for TIMI was 0.757 (95% CI: 0.728-0.785); GRACE, 0.728 (95% CI: 0.701-0.755); and PURSUIT, 0.691 (95% CI: 0.662-0.720). Conclusion: In this large cohort of ED patients, the TIMI risk score had the best discriminatory ability to predict 30-day cardiovascular events.