Purpose: We hypothesized that the vascular protecting effect of an angiotensin receptor blocker (ARB) reduced endothelial damage of the radial artery (RA) after coronary bypass and conducted a comparative study.
Patients and methods: One hundred and sixty four patients were divided into the following two groups, Group C: 92 subjects who were orally administered Candesartan 8 mg/day, Group I: 72 subjects who were administered Imidapril at 5 mg/day. Graft angiography was performed one year after surgery and the RA intima was evaluated using an angioscope.
Results: Total cholesterol of Group C was 151.4+/-66.9 mg/dL, which was significantly lower than in Group I (182.2+/-27.8 mg/dL), and LDL cholesterol of the ARB-treated group, i.e., Group C was 96.1+/-32.5 mg/dL and significantly lower than in Group I (139.1+/-48.7 mg/dL). In angioscopy, yellow plaque was detected in the proximal RA in 7 (8.0%) and 8 (11.6%) patients of the Groups C and I, respectively, showing a lower tendency in the ARB-treated group.
Conclusions: The results of evaluation one year after surgery revealed no significant difference in effects on the RA endothelium between ARB and ACE inhibitor. ARB reduced cholesterol and its effect was confirmed with blood examination data and endoscopic findings.