Performance of the GRACE and the ACTION risk model in the prediction of in-hospital mortality: external validation, model revision and updating in the Thai Percutaneous Coronary Intervention Registry.

Abstract

Background: External validation is crucial before implementing a risk score model in clinical practice. This study examined the performance of Global Registry of Acute Coronary Events (GRACE) and Acute Coronary Treatment and Intervention Outcomes Network (ACTION) Registry-Get With The Guidelines (GWTG) (ACTION Registry-GWTG) Risk Score (AR-G RS) using the Thai Percutaneous Coronary Intervention Registry (TPCIR).

Methods: Included in this study were 11 455 patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) between November 2015 and May 2018. GRACE and AR-G RS models were externally validated, revised and updated using discrimination (C-statistic score) and calibration (Hosmer-Lemeshow (HL) indexes). Clinical predictors were selected stepwise from the multivariate analysis to evaluate the performance of each risk score in the revised and updated model.

Results: In-hospital mortality was 4.4%. GRACE and AR-G RS demonstrated good discrimination for in-hospital mortality (C-statistics 0.8957 and 0.8823, respectively) with optimal calibration (HL, p=0.036 and 0.006, respectively) and penalty rates of 0.005 and 0.006, respectively. The updated model significantly improved the discrimination performance compared with the original GRACE and AR-G RS models, with a C-statistic of 0.9118 and a penalty of 0.006.

Conclusion: GRACE and AR-G RS maintained a good performance in TPCIR. Based on routine PCI practice, we demonstrated that the updated model could improve the accuracy of GRACE and AR-G RS in predicting in-hospital mortality among patients with ACS who underwent PCI.