Predictors of circulating endothelial progenitor cell levels in patients without known coronary artery disease referred for multidetector computed tomography coronary angiography

Abstract

IntroductionEndothelial progenitor cells (EPCs) have an important role in vascular repair. Levels in peripheral circulation are thought to be related to overall cardiovascular risk and may represent potential therapeutic targets. The aim of this work is to identify predictors of circulating EPC concentrations in patients without known coronary artery disease (CAD). MethodsThe study population consisted of 215 patients without known CAD referred for multidetector computed tomography (MDCT) coronary angiography (CTA) during a 6-month period. All patients underwent: 1) short anamnesis; 2) anthropometric measurements; 3) blood pressure and heart rate assessment; 4) blood tests; and 5) MDCT (including quantification of visceral fat, quantification of coronary artery calcification [CAC] and CTA). ResultsThe patients’ mean age was 58±11 years (26-84) and 61% were male. Dyslipidemia (59%) and hypertension (57%) were the most prevalent risk factors. Twenty-seven percent met the ATP III criteria for metabolic syndrome. Mean Framingham risk score was 12±9%. Sixty-seven percent had no significant CAD but 64% had some degree of coronary calcification. The mean CAC (Agatston) was 186±433.Mean EPC concentration, expressed as a percentage of total white blood cells, was 0.05±0.08% (0.0-0.58%). EPCs were inversely related to the presence of diabetes mellitus and smoking, and positively related to C-reactive protein. No significant correlations were found between EPCs and other risk factors, measurements of adiposity, atherosclerotic burden or severity of CAD. ConclusionIn patients without known CAD referred for MDCT, EPC levels in peripheral blood cannot be significantly estimated or predicted from knowledge of patient anamnesis, risk factors, visceral fat, CAC or CTA.