Joint effects of C-reactive protein and glycated hemoglobin in predicting future cardiovascular events of patients with advanced atherosclerosis

Background-C-reactive protein (CRP) and glycohemoglobin (HbA1c) are established risk factors for the development of cardiovascular disease. We investigated the joint effects of these parameters on cardiovascular outcome of patients with advanced atherosclerosis. Methods and Results-We studied 454 patients with advanced atherosclerosis (median age, 69 years; 264 male). Cardiovascular risk profile, high-sensitivity CRP (hs-CRP), and HbA1c were obtained at baseline, and patients were followed for a median of 21 months (interquartile range, 13 to 26) for the occurrence of major adverse cardiovascular events (MACE) (myocardial infarction, percutaneous coronary interventions, coronary artery bypass graft, carotid revascularization, stroke, and death). We observed 166 MACE in 128 patients (28%). Cumulative event-free survival rates at 6, 12, and 24 months were 91%, 85%, and 73%, respectively. Adjusted hazard ratios for the occurrence of MACE according to increasing quartiles of hs-CRP and HbA1c were 1.35 (P=0.31), 1.90 (P=0.026) and 2.13 (P=0.007), and 1.40 (P=0.26), 1.81 (P=0.059), and 2.36 (P=0.023), respectively, compared with the lowest quartiles. Considering both parameters jointly, we found that patients with hs-CRP>0.44 mg/dL and HbA1c>6.2% (upper quartiles) were at highest risk for MACE, with each parameter adding to the prognostic information of the other. Conclusions-Inflammation, indicated by hs-CRP, and hyperglycemia, indicated by HbA1c, jointly contribute to the cardiovascular risk of patients with advanced atherosclerosis. Patients with both hs-CRP and HbA1c in the upper quartiles (>0.44 mg/dL and >6.2%, respectively) are at particularly high risk for poor cardiovascular outcome.