Correlation of angiotensin converting enzyme gene polymorphism with perioperative myocardial protection under...

To observe the expression of angiotensin converting enzyme (ACE), angiotensin II (Ang II), cardiac troponin (cTn I), creatine kinase isozymes (CK-MB) and muscle red protein(Myo) after cardiopulmonary bypass (CPB), and to investigate the association of polymorphisms in angiotensin converting enzyme genes and myocardial injury.

Sixty-three patients suffered from rheumatic mitral stenosis and scheduled for mitral valve replacement with CPB, were randomly divided into three groups according polymorphisms in angiotensin converting enzyme genes: type II, type ID, type DD (each=21). Blood samples were withdrawn from artery before operation (T1), at the beginning of CPB (T2), 30 min after CPB (T3), (T4) at the end of CPB (T5), 2 h after CPB (T6), 6 h after CPB (T7) to measure the expression of ACE, Ang II, cTn I, CK-MB, Myo.

The level of ACE during and after CPB were significantly higher than those before CPB (P<0.05). As extension of CPB time, the expression of ACE was increased. The level of cTn I, CK-MB, Myo after CPB were significantly higher than those before CPB(P<0.05). The level of cTn I, CK-MB and Myo were highest at T7, T6 and T5 and T7, respectively. The level of ACE, Ang II cTn I in patients with DD genotype was significantly higher than the ID and II genotype (P< 0.05). Besides, the level of ACE, Ang II in patients with ID genotype was significantly higher than the II (P< 0.05).

There is certain correlation between CPB perioperative midterm ACE and cTn I, Myo, CK-MB. ACE DD genotype is a susceptibility gene of the CPB perioperative myocardial injury.