Effect Of Cardiopulmonary Bypass On Circulating Endothelial Progenitor Cells In Infants With Congenital Heart Disease Associated With Pulmonary Arterial Hypertension

Backgroud Cardiopulmonary bypass(CPB) provided a relatively bloodless and quiet field, but it also caused heart,lung and systematic injury during the operation, particularly in infants with congenital heart disease associated with pulmonary arterial hypertension. Recent studies showed that the endothelial progenitor cells (EPCs) played an important role in angiogenesis and vascular healing, can reduce acute lung injury and prevent pulmonary aterial hypertension. However, less is known about the circulating levels of EPCs after CPB. This study aimed to observe the influence of cardiopulmonary bypass on circulating EPCs in infants with congenital heart disease associated with pulmonary arterial hypertension, and to explore the possible relationship between circulating EPCs level and lung injury after CPB.Methods Between July 2010 and December 2010, 40 infants with congenital heart disease and pulmonary arterial hypertension were divided into CPB group and off-pump group. In off-pump group, 20 cases received ligation of patent ductus arteriosus and closure of artrial sepectal defect without cardiopulmonary bypass. In CPB group, 20 cases had open heart operations with cardiopulmonary bypass. The number of circulating EPCs assayed by flow cytometer at anesthesia completion(T1), the end of CPB(T2), 4h(T3), 24h(T4)and 72h(T5) after operations, and arterial blood gas analysis were performed at the same time. The relation of CPB time, EPCs number and oxygenation index was analyzed.Results In CPB group, the number of circulating EPCs per 2×105 mononuclear cells in peripheral blood was T1(62.05±19.24), T2(37.50±15.08), T3(124.40±44.04), T4(18.60±11.70), and T5(31.80±13.45) respectively. In off-pump group, the number of circulating EPCs per 2×105 mononuclear cells in peripheral blood was T1(61.30±17.87), T2(62.15±17.08), T3(63.95±19.00), T4(58.20±17.17), and T5(59.50±18.32), respectively. The number of circulating EPCs in the two groups had no statistically significant differences at T1 (P>0.05). The number of circulating EPCs in CPB group was higher significantly than that in off-pump group at T3 (P<0.01). The number of circulating EPCs at T2, T4, T5 in CPB group was lower significantly than that at T1 and those time points in off-pump group (P<0.01).There was a negative correlation between CPB time and circulating EPCs at T2 (r=-0.69, P<0.01); There was a positive correlation between CPB time and circulating EPCs at T3 (r=0.74, P<0.01). Oxygenation index in two group had no statistically differences at T1. Oxygenation index in CPB group was lower than those in off-pump group at T1, T3 and T4. There was a negative correlation between CPB time and the oxygenation index at T2 (r=-0.76, P<0.01). There was a positive correlation between oxygenation index and the number of circulating EPCs at T2 (r=0.91, P<0.01).Conclusions⑴The levels of circulating EPCs reduced after CPB.⑵The number of circulating EPCs can predict the serverity of lung injury, and may play an important role in lung injury healing.