Influence Of Deep Hypothermic Circulatory Arrest On Circulating Endothelial Progenitor Cells In Infants With Congenital Heart Disease And Pulmonary Arterial Hypertension

Objective:Despite brain can tolerate a long time of ischemia and hypoxia under deep hypothermic circulatory arrest (DHCA), cerebral injury is still the major complication after aortic arch surgery with DHCA. Accumulating evidence showed that the cerebral complication was related to the injury of cerebrovascular endothelium, and that endothelial progenitor cells (EPCs) played an important role in angiogenesis and vascular healing. However, less is known about the levels of circulating EPCs after DHCA, this study investigates the changes of circulating EPCs after DHCA in infants with congenital heart disease and pulmonary arterial hypertension.Methods:Between July 2010 and December 2010, 30 infants with congenital heart disease and pulmonary arterial hypertension (pulmonary artery systolic pressure/systematic artery systolic pressure≥0.45), aged 2 months to 36 months, underwent cardiovascular operations were divided into cardiopulmonary bypass without DHCA group(CPB group), cardiopulmonary bypass with DHCA and regional cerebral perfusion(RCP) group(DHCA+RCP group). The number of circulating EPCs of all infants assayed by flow cytometer at following time points: anesthesia completion(T1), the end of CPB (T2), 4h(T3), 24h(T4)and 48h(T5) after the surgery. The level of circulating EPCs was expressed as the number of coexpressing CD34+ and CD133+ of 2×105 Peripheral blood mononuclear cells.CPB time, aortic clamp time, and DHCA+RCP time, recovery time of consciousness, intubation time and ICU stay time after operation were also obtained. The differences of circulating EPCs levels in two groups and the relation between circulating EPCs levels and postoperative recovery were investigated.Results: 1. The number of circulating EPCs in CPB group at T1, T2, T3, T4 and T5 was 62.06±20.24, 37.50±15.79, 124.39±44.91, 18.33±12.15 and 31.67±10.93 respectively. The number of circulating EPCs in DHCA+RCP group at T1, T2, T3, T4 and T5 was 69.00±41.11, 24.92±15.87, 78.00±48.92, 30.42±23.17, 28.33±11.40 respectively. In the both groups, the number of circulating EPCs at T2, T4, T5 was significantly lower than that at T1(P<0.05). The number of circulating EPCs in CPB group was significantly higher at T3 than that at T1(P<0.05), However, the number in DHCA+RCP group just slightly increased(P>0.05).2. Between the twp groups, there was no statistical difference in the number of circulating EPCs at T1, T4, T5 (P>0.05). But at T2 and T3, the number of circulating EPCs was lower in DHCA+RCP group than that in CPB group(P<0.05).3. The circulating EPCs levels in DHCA+RCP group at T2 have negative correlation with CPB time(r=-0.621, P<0.05), aortic clamp time(r=-0.382, P>0.05) and DHCA+RCP time (r=-0.965, P<0.01).4. The circulating EPCs levels in DHCA+RCP group at T2 have negative correlation with recovery time of consciousness (r=-0.625, P<0.05), intubation time (r=-0.647, P<0.05) and ICU stay time (r=-0.642, P<0.05) postoperatively.Conclusions: The number of circulating EPCs reduced after isolated CPB and CPB with DHCA+RCP, and the effects of DHCA on EPCs are greater than CPB in infants with congenital heart disease and pulmonary arterial hypertension.