Predischarge C-Reactive Protein and 1-year Outcome After Acute Coronary Syndromes

Abstract 

Purpose

To investigate the relationship between high-sensitivity C-reactive protein and cardiovascular events following acute coronary syndrome.

Methods

This nationwide, cross-sectional, prospective study involved 439 patients with an acute coronary syndrome who presented to the hospital within 24 hours of symptom onset. Patients with a concomitant inflammatory process were excluded. Predischarge C-reactive protein samples were measured using a high-sensitivity method in a core laboratory. The outcome was the composite of death, acute myocardial infarction, stroke/transient ischemic attack, urgent hospitalization for unstable angina, and urgent revascularization within 1 year.

Results

At 1 year, event rates were 10.2% for the lowest, 8.2% for the middle, and 11.0% for the highest C-reactive protein tertiles (P = .75) with similar event-free survival (P = .70). The hazard ratio (HR) for event rates between the highest and lowest tertiles was 1.10 (95% confidence interval [CI]: 0.54 to 2.20) There was marked overlap of C-reactive protein values between patients with and without events (median [interquartile range]: 8.39 [3.27 to 32.63] vs 9.55 [4.07 to 24.02], respectively; P = .91). C-reactive protein was not an independent predictor of 1-year events (HR for highest tertile: 1.19; 95% CI: 0.58 to 2.43; P = .64) and performed poorly on receiver operating characteristic curve analysis (C statistic = 0.51).

Conclusion

Predischarge high-sensitivity C-reactive protein level is a poor predictor of cardiovascular events at 1 year after acute coronary syndrome.

Keywords: High-sensitivity C-reactive protein, Acute coronary syndromes, Cardiovascular events, Outcomes