Modification of the GRACE Risk Score for Risk Prediction in Patients With Acute Coronary Syndromes

Key PointsQuestionDoes a modified Global Registry of Acute Coronary Events (GRACE) risk score incorporating high-sensitivity cardiac troponin (hs-cTn) T at presentation as a continuous rather than a binary variable improve risk prediction in patients with acute coronary syndromes (ACS)? FindingsIn this cohort study composed of 3 independent cohorts of 9803 patients with ACS, the incorporation of continuous hs-cTn T at presentation conferred improved discrimination and reclassification compared with the original GRACE score for the prediction of in-hospital, 30-day, and 1-year mortality. MeaningIn this study, using continuous rather than binary hs-cTn T at presentation substantially improved GRACE risk score performance for the prediction of short-term and long-term mortality across the whole spectrum of ACS. This cohort study assesses the incremental predictive value of a modified Global Registry of Acute Coronary Events score incorporating high-sensitivity cardiac troponin T at presentation, a surrogate of the extent of myocardial injury. ImportanceThe Global Registry of Acute Coronary Events (GRACE) risk score, a guideline-recommended risk stratification tool for patients presenting with acute coronary syndromes (ACS), does not consider the extent of myocardial injury. ObjectiveTo assess the incremental predictive value of a modified GRACE score incorporating high-sensitivity cardiac troponin (hs-cTn) T at presentation, a surrogate of the extent of myocardial injury. Design, Setting, and ParticipantsThis retrospectively designed longitudinal cohort study examined 3 independent cohorts of 9803 patients with ACS enrolled from September 2009 to December 2017; 2 ACS derivation cohorts (Heidelberg ACS cohort and Newcastle STEMI cohort) and an ACS validation cohort (SPUM-ACS study). The Heidelberg ACS cohort included 2535 and the SPUM-ACS study 4288 consecutive patients presenting with a working diagnosis of ACS. The Newcastle STEMI cohort included 2980 consecutive patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention. Data were analyzed from March to June 2023. ExposuresIn-hospital, 30-day, and 1-year mortality risk estimates derived from an updated risk score that incorporates continuous hs-cTn T at presentation (modified GRACE). Main Outcomes and MeasuresThe predictive value of continuous hs-cTn T and modified GRACE risk score compared with the original GRACE risk score. Study end points were all-cause mortality during hospitalization and at 30 days and 1 year after the index event. ResultsOf 9450 included patients, 7313 (77.4%) were male, and the mean (SD) age at presentation was 64.2 (12.6) years. Using continuous rather than binary hs-cTn T conferred improved discrimination and reclassification compared with the original GRACE score (in-hospital mortality: area under the receiver operating characteristic curve [AUC], 0.835 vs 0.741; continuous net reclassification improvement [NRI], 0.208; 30-day mortality: AUC, 0.828 vs 0.740; NRI, 0.312; 1-year mortality: AUC, 0.785 vs 0.778; NRI, 0.078) in the derivation cohort. These findings were confirmed in the validation cohort. In the pooled population of 9450 patients, modified GRACE risk score showed superior performance compared with the original GRACE risk score in terms of reclassification and discrimination for in-hospital mortality end point (AUC, 0.878 vs 0.780; NRI, 0.097), 30-day mortality end point (AUC, 0.858 vs 0.771; NRI, 0.08), and 1-year mortality end point (AUC, 0.813 vs 0.797; NRI, 0.056). Conclusions and RelevanceIn this study, using continuous rather than binary hs-cTn T at presentation, a proxy of the extent of myocardial injury, in the GRACE risk score improved the mortality risk prediction in patients with ACS.