Angiotensin Converting Enzyme Insertion/Deletion Polymorphism and Occlusion of Vein Grafts in Long-term Post-CABG

The relation between angiotensin converting enzyme (ACE) insertion/deletion (I/D) polymorphism and cardiovascular diseases was reported previously but the role of this polymorphism and the occlusion of vein grafts in long-term post coronary artery bypass graft (CABG) surgery still has remained controversial. The aim of the present study was to investigate any probable relationship between ACE I/D polymorphism and the atherosclerotic occlusion of vein grafts.

Patients who undergone CABG surgery more than five years ago, participated in this cross-sectional study. Occlusion of vein graft was determined by angiography. The ACE I/D polymorphism was detected by polymerase chain reaction (PCR) based restriction analysis.

A total of 102 patients (84 males) were enrolled to the study. The frequency distribution of DD, ID, and II polymorphisms were 23.6%, 62.7%, and 13.7%, respectively. There were no differences among genotypic groups regarding the number of occluded, diseased, and atherosclerosis-free vein grafts (P = 0.6, 0.7, and 0.18, respectively). Patients with II genotype had the same number of completely occluded vein grafts in a marginally significant shorter time after CABG (P = 0.06) compared with the other groups.

Although the results of our study indicated no association of ACE I/D polymorphisms and the occlusion of vein grafts long-term post-CABG, ACE II genotype may accelerate the rate of occlusion in vein grafts.