Different apparent prognostic value of hsCRP in type 2 diabetic and nondiabetic patients with acute coronary syndromes

BACKGROUND: C-reactive protein (CRP) is an established prognostic marker in acute coronary syndromes (ACS); however, no study has specifically addressed its prognostic role in type 2 diabetes with ACS. We evaluated the prognostic role of CRP separately in diabetic and nondiabetic patients with ACS. METHODS: We enrolled 251 patients with unstable angina and measured serum concentrations of high sensitivity (hs)CRP. Ninety-seven patients underwent coronary angiography with evaluation of atherosclerotic disease severity and extent by Bogaty score. Assessed endpoint was the combined occurrence of myocardial infarction (MI) and death at 1 year. RESULTS: No significant differences were found in hs-CRP between patients with and without diabetes. By Cox regression, hsCRP was not associated with 1-year follow-up events in diabetic patients but was strongly associated with events in nondiabetic patients (P = 0.0012). Coronary angiography exhibited a higher extent index in patients with diabetes than in those without (P = 0.04). hsCRP concentrations were not associated with angiographic atherosclerotic burden. By Cox analysis, hsCRP and extent score were associated with events in patients who underwent coronary angiography (P < 0.001 and P = 0.034, respectively). In nondiabetic patients, hsCRP was the only predictor of events at 1-year follow-up (P < 0.001), whereas in diabetic patients, hsCRP was not associated with events and a weak association was observed for extent score (P = 0.06). CONCLUSIONS: Our study suggests that different pathophysiological mechanisms may be responsible for MI and death in unstable angina patients with or without diabetes and that severity of coronary artery disease plays a major role in diabetes (and inflammation in the absence of diabetes).