Abstract 2873: Association of Endothelial Precursor Colony Counts with Cardiovascular Risk Burden

Abstract

Studies investigating endothelial progenitor cell levels and cardiovascular (CVD) risk and outcomes have yielded contradictory information based on the assays employed. Culture assays of early ``angiogenic” endothelial cells differ from the late outgrowth ``proliferative” ones. We hypothesized that the number of colonies, representing the circulating pool of endothelial precursors, will be significantly stimulated by the presence of CVD and risk factors (RF). Methods We performed an ``intermediate” duration assay where peripheral blood mononuclear cells were cultured on fibronectin plates for 7 days and the number of colonies with endothelial-type cells at their periphery were counted by the same technician in all subjects. We sampled 420 subjects who either: were healthy and free of RF (n = 36, age = 47 ± 10), had metabolic syndrome, overt diabetes, or increased carotid thickness (n = 131, age = 59 ± 10), had coronary artery disease (n = 206, age = 61 ± 10), or peripheral vascular disease (n = 45, age = 64 ± 8). Results Endothelial precursor colony counts were lowest in the healthy subjects, higher in patients with RF, and highest in those with CVD (Figure ). These differences persisted after correcting for age. Conclusion Our data unequivocally demonstrates that the numbers of cultured endothelial colonies, utilizing an intermediate duration assay, are stimulated by the presence of risk factors, sub-clinical disease and overt CVD. This illustrates the presence of a reparative or compensatory regenerative response by endothelial progenitors to vascular injury. Whether an inadequate repair response is associated with increased risk needs to be further studied.