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) wascreated and validated specifically for this clinical scenario, while theGRACE score is generic to any type of acute coronary syndrome.

Objective

Between TIMI and GRACE scores, identify the one of better prognosticperformance in patients with STEMI.

Methods

We included 152 individuals consecutively admitted for STEMI. The TIMI andGRACE scores were tested for their discriminatory ability (C-statistics) andcalibration (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 opposedto the GRACE Score that showed predominant distribution at low risk (80 %,13 % and 7%, respectively). Case-fatality was 11%. The C-statistics of theTIMI 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 calibrationrepresented by χ2 = 1.4 (p = 0.92), well above the calibration of theGRACE score, which showed χ2 = 14 (p = 0.08). This calibration isreflected in the expected incidence ranges for low, intermediate and highrisk, according to the TIMI score (0 %, 4.9 % and 25 %, respectively),differently to GRACE (2.4%, 25% and 73%), which featured middle rangeincidence inappropriately.

Conclusion

Although the scores show similar discriminatory capacity for hospital death,the TIMI score had better calibration than GRACE. These findings need to bevalidated populations of different risk profiles.