Risk stratification and prognostic implication of plasma biomarkers in nondiabetic patients with stable coronary artery disease - The role of high-sensitivity C-reactive protein

Study objectives: To evaluate the implication of plasma biomarkers to future cardiovascular events in nondiabetic patients with stable coronary artery disease (CAD). Designs and settings: Prospective, follow-up study at a tertiary referral center. Patients and measurement: Serial plasma biomarkers including high-sensitivity C-reactive protein (hsCRP), homocysteine, soluble adhesion molecules, von Willebrand factor, and lipid profiles were determined before coronary angiograms in a series of nondiabetic CAD patients with stable angina. Among them, 75 consecutive patients who received coronary revascularization (48 coronary interventions and 27 coronary bypass surgeries) later and another 75 age- and gender-matched patients who preferred medical treatment were both enrolled. In patients of each group, major cardiovascular events including cardiac death, nonfatal myocardial infarction, new or repeated coronary revascularization, and hospitalization for unstable angina, stroke, or peripheral artery disease were prospectively followed up for at least 6 months. Results: Patients were followed up to 40 months (median, 18 months). The incidences of major cardiovascular events were similar between the two groups. For patients with medical treatment, plasma levels of hsCRP, homocysteine, low-density lipoprotein, and the ratio of total cholesterol (TC) to high-density lipoprotein cholesterol (HDL-C) were significantly higher in those with cardiovascular events than those without. However, only hsCRP > 0.1 mg/dL (relative risk [RR], 2.78; 95% confidence interval [CI], 1.21 to 6.41; p = 0.016) and TC/HDL-C ratio > 4.8 (RR, 2.42; 95% CI, 1.04 to 5.65; p = 0.041) were independent predictors by multivariable analysis. For patients with revascularization, basal plasma hsCRP levels were higher in those with cardiovascular events than those without (p = 0.04). However, no biochemical markers could predict future major cardiovascular events in these patients. Conclusions: In nondiabetic patients with CAD, basal plasma hsCRP levels were increased with future cardiovascular events regardless of different treatment strategies. Both plasma hsCRP level and TC/HDL-C ratio independently predict future cardiovascular events, confirming the role of plasma biomarkers in clinical risk stratification especially in patients with medical treatment.