Protection of coronary angioplasty-induced oxidative stress by Isovue used during angioplasty

Abstract

Background: Oxygen free radicals (OFRs) have been implicated in ischemic-reperfusion cardiac injury. Use of percutaneous transluminal coronary angioplasty (PTCA) has created renewed interest in salvation of ischemic myocardium. The PTCA procedure is similar to the ischemia-reperfusion model. It is possible that OFRs are increased following PTCA. However, OFR-related cardiac complications are uncommon and the evidence for lipid peroxidation is conflicting.

Patients and methods: In this study the levels of plasma malondialdehyde, OFR-producing activity of polymorphonuclear leukocytes (PMNL-CL) and blood antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase) were measured in peripheral venous blood of 50 consecutive patients with stable angina undergoing elective PTCA. The ability of Isovue (used during PTCA) and of streptokinase (used during thrombolysis) to scavenge OH in the high performance liquid chromatography method and to reduce OH-induced lipid peroxidation were also assessed. Patients were divided into three groups: group 1, single vessel PTCA; group 2, two or more vessel PTCA; and group 3, combined single and multivessel PTCA.

Results: The results indicated that there was an increase in PMNL-CL (22% to 44%) and a decrease in plasma malondialdehyde (33% to 40%) at 60 mins following PTCA. The activity of antioxidant enzymes remained unaltered. Isovue scavenged OH in a concentration-dependent manner and was complete at a concentration below that used in patients. Streptokinase, on the other hand, was ineffective in scavenging OH.

Conclusions: These results suggest that, in spite of increased production of OFR by polymorphonuclear leukocytes and unaltered activity of antioxidant enzymes, lipid peroxidation decreased. Lack of lipid peroxidation may have been due to the OH-scavenging property of Isovue. The observed differences in OFR-related complications between PTCA and thrombolytic therapy may have been due to the antioxidant activity of Isovue.