Hyperhomocysteinemia-induced myocardial injury after coronary artery bypass.

Hyperhomocysteinemia and other major cardiovascular risk factors are associated with increased vascular oxidative stress. To access the effects preoperative plasma homocysteine levels and other atherosclerotic risk factors on myocardial ischemia-reperfusion injury after conventional coronary artery bypass, 213 patients with normal renal function were enrolled prospectively. Cardiac troponin T was measured postoperatively to determine myocardial injury. There was a significant relationship between hyperhomocysteinemia and postoperative peak troponin T. This was more marked in patients without major atherosclerotic risk factors than in those who had at least one risk factor. Moreover, among current cigarette smokers, those with the highest preoperative plasma homocysteine levels had the lowest postoperative troponin T levels. From multivariate linear regression analysis, the predictors of high postoperative troponin T were hyperhomocysteinemia, hypertension, and aortic crossclamp time, but the presence of major atherosclerotic risk factors paradoxically modified the effects of hyperhomocysteinemia on postoperative myocardial ischemia-reperfusion injury.