GRACE Score for Diagnosis of Acute Coronary Syndrome
Abstract & Commentary
By Michael H. Crawford, MD, Editor
Source: Bajaj RR, et al. Treatment and outcomes of patients with suspected acute coronary syndromes in relation to initial diagnostic impressions (insights from the Canadian Global Registry of Acute Coronary Events [GRACE] and Canadian Registry of Acute Coronary Events [CANRACE]). Am J Cardiol 2013;111:202-207.
The accurate and timely recognition of acute coronary syndromes (ACS) may facilitate the deployment of evidence-based therapies that could impact outcomes. The TIMI risk score is widely used for this purpose, but wasn’t designed for triaging and has significant limitations due to equal weighting of markedly disparate clinical features, e.g., aspirin use and elevated troponin. The Global Registry of Acute Coronary Events (GRACE) risk score is believed to be more robust, but is more complicated and difficult to use without an online calculator. Thus, assessing the real-world accuracy of the GRACE score for triaging potential ACS is of interest. These investigators from Canada studied more than 16,000 patients with suspected ACS who were categorized as possible or definite ACS on admission by the treating physician. Patients with possible ACS had higher GRACE scores vs those with definite ACS (130 vs 125) and were less likely to receive evidence-based therapy in the first 24 hours. The possible ACS patients had more myocardial infarctions (9 vs 2%, P < 0.05) and heart failure (12 vs 9%, P < 0.05). The GRACE score exhibited excellent discrimination on in-hospital mortality in all the patients and both subgroups (predictive accuracy was 0.85 for all patients, 0.83 for possible ACS, and 0.86 for definite ACS). The authors concluded that the GRACE score accurately assessed risk regardless of the initial clinical impression.
About one-third of the patients were categorized initially as possible ACS, yet 76% had a final diagnosis of ACS. Predictors of ACS included the GRACE score and two components of this score, positive biomarkers and ischemic ECG changes. The GRACE score was very accurate, more so than the initial clinical impression. This study has limitations. It is a multicentered registry study and the clinical criteria for the initial categorization of the patients may differ between institutions. In addition, there was no uniform definition of what constituted ACS. Despite these limitations, I believe the study supports the use of the GRACE score for the initial triage of possible ACS patients and suggests that those with high scores get evidence-based medical and invasive therapy regardless of the initial clinical impression.