Novel Antioxidant Therapy Against Myocardial Ischemia-Reperfusion Injury During Percutaneous Coronary Angioplasty

Acute myocardial infarction (AMI) is the leading cause of mortality worldwide. Major advances in the treatment have included coronary interventions, such as systemic thrombolysis and percutaneous coronary angioplasty (PCA). These procedures have been aimed to recover the blood flow in the cardiac zones affected by the occlusion of a branch of the coronary artery. However, damage is generated in the heart tissue known as myocardial reperfusion injury, an event associated with increased oxidative stress. Reactive oxygen species (ROS) are able to trigger cell death pathways, and myocardial structural and functional impairment. Studies on animal models of AMI suggest that lethal reperfusion accounts for up to 50% of the final size of a myocardial infarct, a part of the damage likely to be prevented. Although a number of strategies have been aimed to ameliorate lethal reperfusion injury, up to date the beneficial effects in clinical settings remain elusive. The accumulated body of evidence suggests that redox balance is a crucial determinant of ischemia-reperfusion injury, with clear mechanistic insights into pharmacological approaches. This chapter presents the molecular basis for a novel cardioprotection of patients with AMI subjected to PCA, based on a reinforcement of the antioxidant system.