Accuracy of the GRACE and TIMI scores in predicting the angiographic severity of acute coronary syndrome.

Background: The accuracy of the GRACE and TIMI scores in predicting coronary disease extension in patients with non-ST-elevation acute coronary syndromes (ACS) has not been established.
Objective: To assess the hypothesis that the GRACE and TIMI risk scores satisfactorily predict coronary disease extension in patients withnon-ST-elevation ACS undergoing coronary angiography.
Methods: Individuals meeting the objective criteria for ACS and undergoing coronary angiography during hospitalization were consecutively assessed. Angiographic coronary disease was described as follows: quantification of coronary disease extension by using Gensini score; presence of any coronary artery obstruction (> 70% or > 50% when affecting left main coronary artery); and presence of severe disease (three-vessel disease or affecting the left main coronary artery).
Results: Of 112 patients assessed, a positive correlation of the Gensini score was observed with the GRACE (p = 0.017) and TIMI (p = 0.02) scores, but that association was weak (r = 0.23 and r = 0.27; respectively). The GRACE score could predict neither obstructive coronary disease (area under the ROC curve = 0.57; 95% CI = 0.46 - 0.69), nor severe coronary disease (ROC = 0.59; 95% CI = 0.48 - 0.70). The TIMI score proved to be a modest predictor of coronary disease (ROC = 0.65; 95% CI = 0.55 - 0.76) and of severe coronary disease (ROC = 0.66; 95% CI = 0.56 - 0.76).
Conclusion: (1) There is a positive association between the values of the TIMI or GRACE scores and the extension of coronary artery disease in patients with ACS; (2) however, the degree of that association is not sufficient to make those scores accurate predictors of coronary angiography results.