Prognostic Value of TIMI Score versus GRACE Score in ST-segment Elevation Myocardial Infarction

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.