What is the GRACE Score?
The GRACE (Global Registry of Acute Coronary Events) score is a validated risk stratification tool that predicts in-hospital mortality and death or myocardial infarction at 6 months, 1 year, and 3 years in patients with acute coronary syndromes (STEMI, NSTEMI, and unstable angina), demonstrating excellent discrimination with a C-statistic of 0.83. 1
Purpose and Clinical Application
The GRACE risk model is specifically designed to guide treatment type and intensity in patients with acute coronary syndromes by quantifying mortality risk. 1 The ACC/AHA guidelines recommend calculating the GRACE score at hospital admission for all confirmed ACS patients to predict both short-term and long-term outcomes. 2
The 8 Variables in the GRACE Score
The GRACE model incorporates eight clinical variables, each with specific odds ratios for mortality prediction: 1
- Age (OR 1.7 per 10 years) 1
- Killip class (OR 2.0 per class) - reflecting heart failure severity 1
- Systolic blood pressure (OR 1.4 per 20 mm Hg decrease) 1
- Heart rate (OR 1.3 per 30-beat per minute increase) 1
- ST-segment deviation on ECG (OR 2.4) 1
- Cardiac arrest during presentation (OR 4.3) 1
- Serum creatinine level (OR 1.2 per 1-mg per dL increase) 1
- Positive initial cardiac biomarkers (OR 1.6) 1
How to Calculate and Interpret
The sum of individual variable scores is applied to a reference nomogram to determine the corresponding all-cause mortality risk from hospital discharge to 6 months. 1 The GRACE clinical application tool can be downloaded to a handheld device for bedside use and is available at www.outcomes-umassmed.org/grace. 1
Patients with a GRACE score >140 are considered high-risk and require aggressive therapy, including early invasive strategy, intensive antiplatelet therapy, and close monitoring. 2
Validation and Performance
The GRACE risk tool was developed from 11,389 patients in the GRACE registry and validated in subsequent GRACE and GUSTO IIb cohorts. 1 It accurately predicts in-hospital death across all ACS presentations (STEMI, NSTEMI, and unstable angina). 1
The GRACE score demonstrates superior discriminative ability compared to subjective physician assessment for predicting death or MI in patients with ACS. 2 Research confirms excellent discrimination for 1-year mortality in contemporary multiracial cohorts (c-index = 0.77), with particularly strong performance in STEMI patients (c-index = 0.94). 3
Long-term validation studies show the GRACE score maintains excellent discrimination beyond 6 months, accurately predicting mortality up to 4 years post-discharge (C-index 0.80-0.82 at all time points). 4
Comparison to Other Risk Scores
An analysis comparing TIMI, GRACE, and PURSUIT risk scores concluded that all three demonstrated good predictive accuracy for death and MI at 1 year, identifying patients likely to benefit from aggressive therapy including early myocardial revascularization. 1 However, the ACC/AHA guidelines specifically note that GRACE risk assessment has been found superior to subjective physician assessment. 2
Important Limitations
There is insufficient evidence that routine use of risk scores translates into reduced cardiovascular events. 2 The Australian GRACE Risk Score Intervention Study failed to demonstrate added value with routine GRACE implementation, largely because control hospitals performed better than expected. 2
While the GRACE score shows excellent discrimination in type 1 myocardial infarction (AUC 0.83-0.85), its performance is only moderate in type 2 myocardial infarction (AUC 0.73). 5