Clinical Utility of C-Reactive Protein Measured at Admission, Hospital Discharge, and 1 Month Later to Predict Outcome in Patients With Acute Coronary Disease: The RISCA (Recurrence and Inflammation in the Acute Coronary Syndromes) Study

Objectives This study was designed to prospectively determine, in patients with an acute coronary syndrome, whether the inflammatory marker, C-reactive protein (CRP), measured at hospital admission, discharge, and 1 month later has incremental value to predict outcomes at 1 year. Background The clinical utility of CRP measurements in patients with acute coronary syndromes remains uncertain. Limitations of previous studies have been retrospective design and incomplete adjustment for readily available clinical prognosticators. Methods The CRP marker was measured at admission, hospital discharge, and 1 month later in consecutive patients hospitalized for acute coronary syndromes in 8 tertiary and secondary hospitals. The primary outcome was a composite of death, nonfatal myocardial infarction (MI), and unstable angina (UA) with electrocardiogram (ECG) changes at 1 year. Results A total of 1,210 patients, age 62 ± 12 years, 64% with acute myocardial infarction (MI) and 36% with unstable angina (UA), were recruited. At 1 year, the primary outcome occurred in 142 patients (11.7%) and included 58 deaths (4.8%), 79 nonfatal MIs (6.5%), and 26 UA episodes with ECG changes (2.1%). The unadjusted odds ratios (ORs) (95% confidence intervals) of CRP values at admission, hospital discharge, and 1 month later for the occurrence of the primary outcome were 1.20 (1.06 to 1.36), 0.98 (0.85 to 1.14), and 1.23 (1.00 to 1.50), respectively. After multivariate adjustment, ORs were 1.04 (0.91 to 1.20), 0.90 (0.77 to 1.06), and 1.12 (0.93 to 1.34), respectively. The individual components of the primary outcome were also not independently associated with any of the 3 CRP measurements. Conclusions The modest predictive ability of CRP following admission for an acute coronary syndrome disappeared after adjusting for common clinical variables. This large prospective study does not support the incremental value of measuring CRP in this clinical setting.