Permanent atrial fibrillation impairs the function of circulating endothelial progenitor cells

Objective: to determine whether functions of endothelial progenitor cells (EPCs) were impaired in patients with permanent atrial fibrillation (AF). Methods: 35 patients with permanent AF (AF group) and 35 age and sex matched controls (control group) were collected. The numbers of circulating CD34(+)/KDR+ cells were determined with flow cytometry in the two groups. Cell proliferation, tube formation, nitric oxygen (NO) and vascular endothelial growth factor (VEGF) were assayed. Results: the numbers of CD34+/KDR+ cells were lower in the AF group than the control group (20.01 +/- 12.66 /10(5) vs 77.93 +/- 58.93 /10(5), p = 0.022). Colony formation unit (CFU) of EPCs were decreased in AF group compared to the control group(1.76 +/- 0.59 CFU vs 3.45 +/- 0.82 CFU, p = 0.0000). The AF group had lower cell proliferation ability than control group(0.401 +/- 0.113 A vs 0.558 +/- 0.130 A, p = 0.004). Tube formation ability was decreased in AF patients compared to controls(434.30 +/- 96.22 mu m/mm(2) vs 568.09 +/- 196.17 mu m/mm(2), p = 0.041). AF patients had lower VEGF secretion than controls (27.35 +/- 9.93 ng/L vs 41.86 +/- 7.31 ng/L, p = 0.001), they also had lower NO secretion than controls(16.55 +/- 6.92 mu mol/l vs 23.65 +/- 5.48, p = 0.012). Conclusions: proliferation, tube formation and paracrine of EPCs were reduced in patients with permanent AF.