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 /10⁵ vs 77.93 ± 58.93 /10⁵,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 ± 96.22μm/mm² vs 568.09 ± 196.17μm/mm²,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 ± 6.92μmol/l vs 23.65 ± 5.48,p = 0.012).

Conclusions: proliferation, tube formation and paracrine of EPCs were reduced in patients with permanent AF.