Prognostic value of TIMI score versus GRACE score in ST-segment elevation myocardial infarction
Luis C L Correia1, Guilherme Garcia1, Felipe Kalil1
1Escola Bahiana de Medicina e Saúde Pública, Salvador, BA, Brazil.
Insights
For ST-segment elevation myocardial infarction (STEMI), the TIMI score demonstrated superior calibration compared to the GRACE score, despite similar discriminatory ability for hospital death. Further validation in diverse populations is recommended.
Area of Science:
- Cardiology
- Clinical Risk Stratification
- Myocardial Infarction Management
Background:
- The TIMI Score is specific for ST-segment elevation myocardial infarction (STEMI).
- The GRACE score is a generalized tool for acute coronary syndromes.
- Comparing prognostic performance in STEMI is crucial for patient care.
Purpose of the Study:
- To compare the prognostic performance of the TIMI and GRACE scores in patients with STEMI.
- To evaluate the discriminatory ability and calibration of both scores regarding hospital mortality.
Main Methods:
- A cohort of 152 patients admitted for STEMI was analyzed.
- Both TIMI and GRACE scores were calculated for each patient.
- Discriminatory ability (C-statistics) and calibration (Hosmer-Lemeshow test) were assessed against hospital death.
Main Results:
- Both scores exhibited similar discriminatory capacity (C-statistics ≈ 0.87).
- The TIMI score showed significantly better calibration (χ2 = 1.4, p = 0.92) compared to the GRACE score (χ2 = 14, p = 0.08).
- TIMI score accurately predicted risk distribution, while GRACE score overestimated risk in lower categories.
Conclusions:
- The TIMI score offers superior calibration for predicting hospital death in STEMI patients compared to the GRACE score.
- Despite similar discrimination, TIMI's better calibration suggests improved prognostic accuracy in this specific population.
- Validation in varied risk populations is necessary to confirm these findings.
Background:
The TIMI Score for ST-segment elevation myocardial infarction (STEMI) was created and validated specifically for this clinical scenario, while the GRACE score is generic to any type of acute coronary syndrome.
Objective:
Between TIMI and GRACE scores, identify the one of better prognostic performance in patients with STEMI.
Methods:
We included 152 individuals consecutively admitted for STEMI. The TIMI and GRACE scores were tested for their discriminatory ability (C-statistics) and calibration (Hosmer-Lemeshow) in relation to hospital death.
Results:
The TIMI score showed equal distribution of patients in the ranges of low, intermediate and high risk (39 %, 27 % and 34 %, respectively), as opposed to the GRACE Score that showed predominant distribution at low risk (80 %, 13 % and 7%, respectively). Case-fatality was 11%. The C-statistics of the TIMI score was 0.87 (95%CI = 0.76 to 0.98), similar to GRACE (0.87, 95%CI = 0.75 to 0.99) - p = 0.71. The TIMI score showed satisfactory calibration represented by χ2 = 1.4 (p = 0.92), well above the calibration of the GRACE score, which showed χ2 = 14 (p = 0.08). This calibration is reflected in the expected incidence ranges for low, intermediate and high risk, according to the TIMI score (0 %, 4.9 % and 25 %, respectively), differently to GRACE (2.4%, 25% and 73%), which featured middle range incidence inappropriately.
Conclusion:
Although the scores show similar discriminatory capacity for hospital death, the TIMI score had better calibration than GRACE. These findings need to be validated populations of different risk profiles.
More Related Videos
Related Concept Videos
01:30Acute Coronary Syndrome III: Diagnostic Studies
01:30Acute Coronary Syndrome I: Introduction
01:25Imaging Studies for Cardiovascular System VI: Calcium -Scoring CT
01:23Mitral Stenosis II: Clinical features and Diagnostic Tests