Oxidative stress during peripheral angioplasty - Implication for late restenosis?

Background. Percutaneous transluminal angioplasty (PTA) is routine treatmen t for patients with peripheral arterial disease (PAD). The procedure induce s local generation of reactive oxygen species (ROS), such as H2O2. Since th ese have been shown to stimulate vascular smooth muscle cell growth (VSMCG) , we investigated peroxide levels in patients with PAD during PTA and relat ed these results to late clinical outcome. Methods. Thirty patients (17 male, 13 female, 20 Fontain stage II, 10 Fonta ine stage IV, median age 68 years) undergoing PTA of a 2-6 cm stenosis of t he femoral or popliteal artery were included. The procedure was performed s uccessfully in all patients. At follow-up, six months thereafter restenosis was evaluated by duplex sonography. Total peroxide concentrations were det ermined in plasma drawn before, 6, 24 and 48 hours after the procedure by t he "peroxide activity" assay, which is based on the reaction of horseradish peroxidase with plasma peroxides, using tetramethylbenzidine as the chromo genic substrate. Results. The median peroxide level before angioplasty was 280 mu mol/L (ran ge 47-549). Levels were higher in patients with advanced disease, in smoker s and in patients with diabetes. In response to angioplasty, peroxide level s increased within 48 hours (p <0.001). Six months after the procedure, res tenosis was observed in 10/30 (33%) of patients. Clinical outcome was not d ependent upon baseline or postinterventional peroxide levels. Conclusions. Elevated peroxide levels are seen in patients with advanced ar teriosclerotic disease and in those with diabetes, but are not predictive f or late restenosis.