Assessment of oxidative stress in coronary artery bypass surgery: comparison between the global index OXY-SCORE and individual biomarkers

Fabrizio Veglia*a, José P. Werbaa, Elena Tremoli, Isabella Squellerioa, Erminio Sisilloa, Alessandro Parolari, Fabiana Minardia & Viviana Cavalcaa Centro Cardiologico Monzino IRCCS, Milan, Italyb Department of Pharmacological Sciences, University of Milan, Milan, Italyc Institute of Cardiology, University of Milan, Milan, ItalyAddress for Correspondence: Fabrizio Veglia, Unit of Biostatistics, Centro Cardiologico Monzino IRCCS, Via Parea, 4, 20138 Milano, Italy. Tel.: +39 02 5800 2260. Fax: +39 02 5800 2623. E-mail: fabrizio.veglia@ccfm.itThe performances of the OXY-SCORE, a summary index of oxidative stress, and of its individual components (plasma malondialdehyde (MDA), oxidized and reduced glutathione, individual antioxidant capacity, α- and γ-tocopherol and urinary isoprostanes) were assessed in 47 patients undergoing coronary surgery, randomly assigned to cardiopulmonary bypass (CPB) or off-pump procedure (OPCAB) associated with less oxidative stress. The ability of the OXY-SCORE to classify correctly the patients was high (area under the ROC curve 0.90). Only free MDA showed a similar performance, but it was insensitive to the minor variations of the oxidative balance in the OPCAB group.