Chest pain presenting to the Emergency Department--to stratify risk with GRACE or TIMI?

INTRODUCTION: There is a need to stratify risk rapidly in patients presenting to the Emergency Department (ED) with undifferentiated chest pain. The Global Registry of Acute Coronary Events (GRACE) and the Thrombolysis in Myocardial Infarction (TIMI) scoring systems predict outcome of adverse coronary events in patients admitted to specialist cardiac units. This study evaluates the relationship between GRACE score and outcome in patients presenting to the ED with undifferentiated chest pain and establishes whether GRACE is preferential to TIMI in stratifying risk in patients in the ED setting.
MATERIALS AND METHODS: Descriptive study of a consecutive sample of 1000 ED patients with undifferentiated chest pain presenting to Edinburgh Royal Infirmary, Scotland. GRACE and TIMI scores were calculated for each patient and outcomes noted at 30 days. Outcomes included ST and non-ST myocardial infarction, cardiac arrest, revascularisation, unstable angina with myocardial damage and all cause mortality at 30 days. Score and outcome were compared using receiver operator characteristic curves (AUC-ROC).
RESULTS: The GRACE score stratifies risk accurately in patients presenting to the ED with undifferentiated chest pain (AUC-ROC 0.80 (95% CI 0.75-0.85), see Table 1). The TIMI score was found to be similarly accurate in stratifying risk in the study cohort with an AUC-ROC of 0.79 (95% CI 0.74-0.85). It was only possible to calculate a complete GRACE score in 76% (n=760) cases as not all the data variables were measured routinely in the ED.
CONCLUSIONS: GRACE and TIMI are both effective in accurately stratifying risk in patients presenting to the ED with undifferentiated chest pain. The GRACE score is more complex than the TIMI score and in the ED setting TIMI may be the preferred scoring method.