Clinical application of C-reactive protein across the spectrum of acute coronary syndromes

Background: High-sensitivity C-reactive protein (hsCRP) is associated with adverse cardiovascular outcomes in acute coronary syndromes (ACS). The ability to formulate recommendations regarding clinical use of hsCRP is limited by a paucity of data regarding several key issues. The purpose of this study was to evaluate hsCRP across the spectrum of ACS. Methods: hsCRP was measured on admission in 3225 patients with ACS. hsCRP concentrations were compared in patients who suffered an adverse cardiac outcome within 10 months of study entry and in patients who had no adverse event. Because of heterogeneity in the relationship between hsCRP and clinical outcomes, evaluation was limited to patients from whom samples were collected within 48 h of symptom onset. Results: Patients in the highest quartile of hsCRP compared to those in the lowest quartile were at increased risk of death at 30 days [adjusted hazard ratio (adjHR) 4.6, P <0.001] and 10 months (adjHR 3.9, P <0.001). In patients with unstable angina/non-ST-elevation myocardial infarction (STEMI), hsCRP >3 mg/L was associated with increased 10-month mortality (adjHR 2.3, P = 0.002), whereas in STEMI a relationship with mortality was seen at hsCRP >10 mg/L (adjHR 3.0, P = 0.008). Increased concentrations of hsCRP were strongly associated with the development of heart failure at 30 days (adjHR 8.2, P = 0.001) and 10 months (adjHR 2.6, P = 0.014). Conclusion: Increased baseline concentrations of hsCRP are strongly associated with mortality and heart failure across the ACS spectrum. hsCRP measurement should be performed early after presentation and index diagnosis-specific cutpoints should be used.