Effect of ischemic postconditioning on myocardial injury in patients undergoing cardiac valve replacement under cardiopulmonary bypass / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of ischemic postconditioning on myocardial injury in the patients undergoing cardiac valve replacement under cardiopulmonary bypass (CPB).Methods Thirty patients of both sexes,aged 21-59 yr,of American Society of Anesthesiologists physical status Ⅱ or Ⅲ (New York Heart Association Ⅱ or Ⅲ),with left ventricular ejection fraction ≥ 40％,scheduled for elective cardiac valve replacement under CPB,were divided into 2 groups (n=15 each) using a random number tablecontrol group (C group) and ischemic postconditioning group (P group).In group P,ischemic postconditioning was induced by 3 cycles of 30 s aortic unclamping followed by 30 s cross-clamping starting from 5 min before complete opening of the ascending aorta.After induction of anesthesia and before operation (T1),at 1 h after opening of the ascending aorta (T2),at the end of operation (T3),and at 12,24 and 48 h after opening of the ascending aorta (T4-6),blood samples were taken from the radial artery for determination of plasma concentrations of heart-type fatty acid-binding protein (H-FABP),ischemia-modified albumin (IMA),and cardiac troponin Ⅰ (cTnI).Myocardial specimens in the right auricle were obtained at T2,and the pathological changes were examined using an optical microscope.Results The concentrations of plasma cTnI at T2-6 and H-FABP and IMA at T2-5 were significantly higher than those at T1 in the two groups (P＜0.05).Compared with group C,the concentrations of plasma cTnI at T2-6,H-FABP at T2-4,and IMA at T2,3 were significantly decreased (P＜0.05),and the pathological changes of myocardial tissues were significantly reduced in group P.Conclusion Ischemic postconditioning can reduce myocardial injury in the patients undergoing cardiac valve replacement under CPB.