Validity of GRACE Risk Score as a Prognostic Marker of In-hospital Mortality after Acute Coronary Syndrome.

Abstract

To determine validity of GRACE risk score as a determinant of immediate death during hospitalization for Acute Coronary Syndrome (ACS) and analyze the percentage of cardiac deaths among high, intermediate and low risk groups. Cross-sectional study. Coronary Care Unit of Mayo Hospital, Lahore, from April to July 2015. Patients with acute chest pain were selected according to inclusion and exclusion criteria. Online GRACE risk score calculator was used to determine the predicted risk of death following ACS according to the score. Data was analyzed on SPSS 20. Quantitative data was in the form of median (IQR). Discrimination of GRS was evaluated by using c-statistics, area under the ROC curve. Calibration of GRS was tested by Hosmer-Lameshow test. The correlation between GRACE risk score category and predicted risk of death was determined using Kendall's tau-b bivariate correlation test. Shapiro-Wilk test was applied to check normality of data. The various parameters of GRACE score were studied in patients using Mann-Whitney U-test. The statistically significant p-value was <0.05. There were 165 cases in the study. Overall median GRS was 139 (54). In-hospital deaths were 12.2%. Discrimination of GRS evaluated by area under the ROC curve was 0.913 (95% CI 0.843-0.982; p<0.0001). Application of Hosmer-Lameshow test revealed a p-value of 0.236. Kendall's tau-b bivariate correlation coefficient was 0.384 (p<0.001). GRS is an excellent tool to stratify patients of ACS into different risk categories according to various parameters noted at the time of presentation. The risk of predicted death according to the score was variable among different cases, especially those with higher scores. Even though GRS is an effective and valid tool, but it has some tendency of overestimating probability of death following ACS and may require a fine tuning in some cases.