Prognostic usefulness of serial C-reactive protein measurements in ST-elevation acute myocardial infarction

Abstract

It has been reported that increased levels of C-reactive protein are related to adverse long-term prognosis in the setting of ST-segment elevation acute myocardial infarction (MI). In previous studies, the timing of C-reactive protein determination has varied widely. In the present study, serial high-sensitivity C-reactive protein (hsCRP) measurements were performed to investigate if any of the measurements is superior regarding long-term prognosis. A total of 861 consecutive patients admitted for ST-segment elevation MI and treated with intravenous thrombolysis within the first 6 hours from the index pain were included. HsCRP levels were determined at presentation and at 24, 48, and 72 hours. The median follow-up time was 3.5 years. New nonfatal MI and cardiac death were the study end points. By the end of follow-up, cardiac death was observed in 22.4% and nonfatal MI in 16.1% of the patients. HsCRP levels were found to be increasing during the first 72 hours. Multivariate Cox regression analysis demonstrated that hsCRP levels at presentation were an independent predictor of the 2 end points (relative risk [RR] 2.8, p = 0.002, and RR 2.1, p = 0.03, for MI and cardiac death, respectively), while hsCRP levels at 24 hours did not yield statistically significant results (RR 1.4, p = 0.40, and RR 1.1, p = 0.80, for MI and cardiac death, respectively). The corresponding RRs at 48 hours were 1.2 (p = 0.5) for MI and 3.2 (p = 0.007) for cardiac death and at 72 hours were 1.6 (p = 0.30) for MI and 3.9 (p <0.001) for cardiac death. In conclusion, hsCRP levels at presentation represent an independent predictor for fatal and nonfatal events during long-term follow-up. HsCRP levels at 48 and 72 hours, which are close to peak hsCRP levels, independently predict only cardiac death.