Oxidative stress during peripheral angioplasty. Implication for late restenosis

Background. Percutaneous transluminal angioplasty (PTA) is routine treatment for patients with peripheral arterial disease (PAD). The procedure induces local generation of reactive oxygen species (ROS), such as H 2 O 2 . Since these have been shown to stimulate vascular smooth muscle cell growth (VSMCG), we investigated peroxide levels in patients with PAD during PTA and related these results to late clinical outcome. Methods. Thirty patients (17 male, 13 female, 20 Fontain stage II, 10 Fontaine stage IV, median age 68 years) undergoing PTA of a 2-6 cm stenosis of the femoral or popliteal artery were included. The procedure was performed successfully in all patients. At follow-up six months thereafter restenosis was evaluated by duplex sonography. Total peroxide concentrations were determined in plasma drawn before, 6, 24 and 48 hours after the procedure by the peroxide activity assay, which is based on the reaction of horseradish peroxidase with plasma peroxides, using tetramethylbenzidine as the chromogenic substrate. Results. The median peroxide level before angioplasty was 280 μmol/L (range 47-549). Levels were higher in patients with advanced disease, in smokers and in patients with diabetes. In response to angioplasty, peroxide levels increased within 48 hours (p<0.001). Six months after the procedure, restenosis was observed in 10/30 (33%) of patients. Clinical outcome was not dependent upon baseline or postinterventional peroxide levels. Conclusions. Elevated peroxide levels are seen in patients with advanced arteriosclerotic disease and in those with diabetes, but are not predictive for late restenosis.