Protection of coronary angioplasty-induced oxidative stress by Isovue usedduring angioplasty

BACKGROUND: Oxygen free radicals (OFRs) have been im plicated in ischemic-r eperfusion cardiac injury. Use of percutaneous transluminal coronary angiop lasty (PTCA) has created renewed interest in salvation of ischemic myocardi um. The PTCA procedure is similar to the ischemia reperfusion model. It is possible that OFRs are increased following PTCA. However, OFR-related cardi ac complications are uncommon and the evidence for lipid peroxidation is co nflicting. PATIENTS AND METHODS: In this study the levels of plasma malondialdehyde, O FR-producing activity of polymorphonuclear leukocytes (PMNL CL) and blood a ntioxidant enzymes (superoxide dismutase, catalase and glutathione peroxida se) were measured in peripheral venous blood of 50 consecutive patients wit h stable angina undergoing elective PTCA. The ability of sovue (used during PTCA) and of streptokinase (used during thrombolysis) to scavenge . OH in the high performance liquid chromatography method and to reduce . OH-induce d lipid peroxidation were also assessed. Patients were divided into three g roups: group 1, single vessel PTCA; group 2, two or more vessel PTCA; and g roup 3, combined single and multivessel PTCA. RESULTS: The results indicated that there was an increase in PMNL-CL (22% t o 44%) and a decrease in plasma malondialdehyde (33% to 40%) at 60 mins fol lowing PTCA. The activity of antioxidant enzymes remained unaltered. Isovue scavenged . OH in a concentration-dependent manner and was complete at a c oncentration 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 o f OFR by polymorphonuclear leukocytes and unaltered activity of antioxidant enzymes, lipid peroxidation de creased. Lack of lipid peroxidation may hav e been due to the . OH-scavenging property of Isovue. The observed differen ces in OFR-related complications between PTCA and thrombolytic therapy may have been due to the antioxidant activity of Isovue.