Abstract 10363: Myocardial Redox State Predicts Post-Operative Atrial Fibrillation in Cardiac Surgery
Background: Myocardial redox state may be a key feature in cardiac physiology, but their exact role in the development of post-operative complications after coronary artery bypass grafting (CABG) is unclear. We examined the role of systemic and local myocardial redox state, in the development of paroxysmal atrial fibrillation after CABG surgery (Postop AF).
Methods: Samples of plasma and of right atrial appendage were obtained from 303 patients undergoing elective CABG. Myocardial O2- was determined by lucigenin chemiluminescence and ONOO- by urate-inhibitable luminol chemiluminescence. NADPH oxidase activity was estimated by the NADPH-stimulated O2- production and mitochondrial oxidases by the rotenone-inhibitable O2- fraction. Plasma malonyldialdehyde (MDA) was taken as a measure of systemic lipid peroxidation. Patients were followed up prospectively until their discharge from hospital.
Results: During the follow-up period, 3 patients died and 80 developed postop AF. Plasma MDA did not predict postop AF (Panel A). In contrast, right atrial basal (Panel B) and NADPH-stimulated O2- (Panel C) as well as ONOO- (Panel D) but not rotenon-inhibitable O2- (P=NS), were independent predictors of postop AF.
Conclusions: Basal and NADPH-stimulated O2- and ONOO- release from the atrial myocardium are independent predictors of postop AF in patients undergoing CABG. These data suggest that NADPH oxidases may be an important "upstream" therapeutic target for the prevention of postop AF.
- © 2011 by American Heart Association, Inc.