Prevention of postoperative atrial fibrillation: novel and safe strategy based on the modulation of the antioxidant system

• Main Author: Ramón eRodrigo
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2012-04-01
• Series: Frontiers in Physiology
• Subjects: Oxidative Stress; Vitamin E; n-3 polyunsaturated fatty acids; postoperative atrial fibrillation; vitamin C
• Online Access: http://journal.frontiersin.org/Journal/10.3389/fphys.2012.00093/full

Postoperative atrial fibrillation (AF) is the most common arrhythmia following cardiac surgery with extracorporeal circulation. The pathogenesis of postoperative AF is multifactorial. Oxidative stress, caused by the unavoidable ischemia-reperfusion event occurring in this setting, is a major contributory factor. ROS-derived effects could result in lipid peroxidation, protein carbonylation or DNA oxidation of cardiac tissue, thus leading to functional and structural myocardial remodeling. The vulnerability of myocardial tissue to the oxidative challenge is also dependent on the activity of the antioxidant system. High ROS levels, overwhelming this system, should result in deleterious cellular effects, such as the induction of necrosis, apoptosis or autophagy. Nevertheless, tissue exposure to low to moderate ROS levels could trigger a survival response with a trend to reinforce the antioxidant defense system. Administration of n-3 polyunsaturated fatty acids (PUFA), known to involve a moderate ROS production, is consistent with a diminished vulnerability to the development of postoperative AF. Accordingly, supplementation of n-3 PUFA successfully reduced the incidence of postoperative AF after coronary bypass grafting. This response is due to an up-regulation of antioxidant enzymes, as shown in experimental models. In turn, non-enzymatic antioxidant reinforcement through vitamin C administration prior to cardiac surgery has also reduced the postoperative AF incidence. Therefore, it should be expected that a mixed therapy result in an improvement of the cardioprotective effect by modulating both components of the antioxidant system. We present available evidence supporting the view of an effective prevention of postoperative AF including a 2-step therapeutic strategy: n-3 PUFA followed by vitamin C supplementation to patients scheduled for cardiac surgery with extracorporeal circulation. The present study should encourage the design of clinical trials aimed to offer ne