An investigation of the prognostic utility of RANTES levels in predicting mortality in an angiography population

RANTES (Regulated upon activation, normal T cell expressed and secreted) is a chemokine involved in the recruitment and transmigration of leukocytes across the vascular endothelium. A large body of experimental evidence suggests the role of RANTES and its receptor, CCR5, in atherosclerosis and has prompted the study of RANTES as a biomarker of coronary artery disease (CAD). We sought to investigate baseline plasma RANTES as a marker of mortality in a cohort of patients referred for angiography. RANTES levels were measured in 831 patients who were classified by angiogram as positive or negative for CAD. At the time of recruitment, blood samples were collected and later assayed using a commercial ELISA kit for RANTES. Mortality data was collected in 2009 to identify deceased patients and the cause of death. RANTES levels were significantly different between men and women (27.7 ng/mL and 34.2 ng/mL, p=0.001) and between subjects with and without family history of CAD (30.3 ng/mL and 28.1 ng/mL, p=0.006). The predictive value of RANTES levels for CAD was assessed using a multivariate logistic regression model adjusting for traditional markers of CAD. Triglycerides and apolipoprotein B levels were independent predictors, with odds ratios of OR 2.65 [95% CI: 1.05-6.69] and OR 2.65 [95% CI: 1.01-6.93], p<0.001 respectively. RANTES levels were associated with CAD, OR 1.67 [95% CI: 1.00-2.76], p=0.047, although this association was moderate. When divided into quartiles, subjects with a RANTES level above the fourth quartile were associated with a greater risk of CAD, OR 1.73 [95% CI: 1.05-2.86], p=0.031. After a mean follow-up of 11.1 years, 256 of the 831 subjects were deceased. Using a Cox regression model, we assessed the ability of RANTES to predict cardiovascular and all-cause mortality. Only age and smoking status independently predicted death due to any cause (p