What is the role of the Escala (Global Registry of Acute Coronary Events) GRACE score in managing patients with acute coronary syndrome?

The Role of the GRACE Score in Managing Patients with Acute Coronary Syndrome

The GRACE (Global Registry of Acute Coronary Events) score is the recommended primary risk stratification tool for patients with acute coronary syndrome (ACS) due to its superior predictive ability for both short-term and long-term mortality compared to other risk scores and subjective physician assessment. 1, 2

Components of the GRACE Score

The GRACE score uses 8 clinical variables to calculate risk:

• Age
• Killip class
• Systolic blood pressure
• Heart rate
• ST-segment deviation
• Cardiac arrest on admission
• Serum creatinine
• Cardiac biomarker elevation 1, 2

Importantly, these variables have non-linear associations with outcomes, which the GRACE 2.0 calculator incorporates for improved accuracy 3.

Risk Categories and Clinical Implications

The GRACE score categorizes patients into risk groups:

Risk Category	GRACE Score	In-hospital Mortality
Low	≤108	<1%
Intermediate	109-140	1-3%
High	>140	>3%

1, 2

Clinical Applications:

1. Guiding Invasive Strategy Decisions:

   • Patients with high GRACE scores (>140) derive significant benefit from early invasive management
   • The TIMACS trial demonstrated that patients in the highest GRACE tertile (>140) had a significant reduction in primary ischemic endpoints with early intervention 1

2. Predicting Coronary Anatomy Complexity:

   • GRACE scores correlate positively with SYNTAX scores, which measure coronary artery disease complexity
   • A GRACE score ≥126 predicts severe coronary artery disease (SYNTAX ≥33) with moderate accuracy 4
   • A GRACE score of 109 can predict a SYNTAX score ≥23 with 73.5% sensitivity and 60% specificity 5

3. Long-term Prognostication:

   • The GRACE 2.0 calculator provides mortality estimates at hospital discharge, 6 months, 1 year, and 3 years 1, 3
   • It also estimates the combined risk of death or MI at 1 year 3

Comparison with Other Risk Scores

While the TIMI risk score is also widely used, the GRACE score has demonstrated superior predictive ability for mortality:

• GRACE: Uses 8 variables with weighted scoring, predicts in-hospital and long-term mortality
• TIMI: Uses 7 binary variables (each worth 1 point), predicts 14-day outcomes for UA/NSTEMI and 30-day mortality for STEMI 1, 2

The GRACE score has maintained its discriminative accuracy despite advances in ACS management over time, with studies showing consistent c-statistics of 0.82-0.84 for predicting mortality 6, 7.

Important Considerations and Limitations

• The GRACE and TIMI scores should not be used as diagnostic tools but rather for risk stratification after ACS is suspected or confirmed 1
• Despite excellent discrimination, the GRACE score may require recalibration in specific healthcare settings as treatment advances 7
• While the GRACE score is valuable for risk stratification, there is insufficient evidence that routine use in hospitalized ACS patients reduces cardiovascular events 1
• The score can be calculated using web applications or mobile devices available at www.outcomes-umassmed.org/grace 2

Conclusion

The GRACE score provides valuable risk stratification in ACS patients, guiding therapeutic decisions particularly regarding the timing of invasive management. Its predictive accuracy has remained robust despite advances in ACS treatment, making it the preferred risk stratification tool recommended by major cardiovascular societies.