Objective: The aim of this study was to examine the effects of angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARB) drugs group which are used preoperatively by coronary artery patients with planned operation on the nitric oxide (NO) levels in internal mammarian artery (IMA) and saphenous vein tissues used as coronary artery graft.

Material and Method: In this study, patients were divided into three groups: 1- The group using ramipril as ACE inhibitor, 2- The group using valsartan as ARB, and 3- The control group have been administered to the patients at least eight days before operation. NO, nitrite, and nitrate levels were biochemically measured in blood, saphenous vein, and IMA tissue samples collected preoperatively.

Results: It was determined that while ramipril significantly increased the NO level in both blood and IMA tissue compared to the control group, valsartan significantly increased the NO level in saphenous vein tissue compared to both the control and ramipril group.

Conclusion: It is thought that the significant increase in NO levels determined by us in saphenous vein and IMA graft tissues through administration of one of the ACE inhibitors and ARBs at a tolerable level among coronary artery patients receiving surgical treatment, will affect lifespan and quality of life of the patient positively by providing sufficient patency duration and blood flow of coronary artery grafts.