Does high-sensitivity C-reactive protein add prognostic value to the TIMI-Risk Score in individuals with non-ST elevation acute coronary syndromes?

BACKGROUND: C-reactive protein (CRP) measured at hospital arrival of patients with non-ST elevation acute coronary syndromes (ACS) may add prognostic information to the TIMI-Risk Score.

METHODS: Eighty-six consecutive patients admitted with unstable angina or non-ST-elevation acute myocardial infarction and symptoms onset within the prior 48 h were included. Recurrent cardiovascular events during hospitalization were defined as non-fatal myocardial infarction or death. Serum CRP was measured immediately at hospital arrival and its prognostic value in relation to in-hospital cardiovascular events was tested by the area under the ROC curve and adjusted for TIMI risk predictors by logistic regression analysis. In addition, a CRP modified TIMI-Risk score was created by adding 2 points if CRP greater than the cut-off proposed by the ROC curve analysis. The accuracy of this new score was compared with the usual TIMI-Risk Score.

RESULTS: A significant predictive value of CRP in relation to in-hospital cardiovascular events was indicated by an area under the ROC curve of 0.80 (95% CI=0.66 to 0.93, p=0.009). C-reactive protein cut-off point of best prognostic performance was 7.2 mg/l. In the multivariate analysis, increased CRP (>7.2 mg/l) remained a significant predictor of events after adjustment for TIMI risk predictors (OR=14; 95% CI=1.6-121; p=0.018). The area under the ROC curve for the TIMI-Risk Score was 0.87 (95% CI=0.76-0.99, p=0.001). The addition of CRP to the TIMI-Risk Score improved its prognostic value (area under the ROC curve=0.93; 95% CI=0.87-0.99, p<0.001). The additional value of the new score is demonstrated by a higher specificity (86% vs. 63%, p<0.001) and positive predictive value (39% vs. 19%) in relation to the TIMI-Risk Score.

CONCLUSIONS: CRP measured at admission of patients with non-ST-elevation acute coronary syndromes adds prognostic information to the TIMI-Risk Score. Additionally, the incorporation of this variable into the TIMI-Risk Score calculation is an effective manner to utilize CRP for risk stratification.