Prospects for antioxidant therapy in cardiovascular medicine

Abstract

The papers presented in this supplement provide a detailed and thoughtful overview of the role of free radicals and/or oxidant stress during ischemia and reperfusion under a variety of experimental and clinical circumstances. Considerable emphasis has been given to regional ischemia and evolving infarction, where early reperfusion by thrombolysis has now become a routine clinical procedure. It has become clear that it would be of considerable importance if interventions could be developed that, when given just prior to (or at th~ ~ime of) reperfusion, would reduce tissue injury and limit the size of the evolving infarct. It has beC0m~ evident from the presentations that there is c0nsiderable interest in the possibility that such interventions may also be used to overcome myocardial stunning [1-4] and, as a consequence, accelerate the rate of postischemic functional recov= Cry. In the surgical arena, there is interest in improving the rate and extent of contractile recovery following the period of global ischemia that occurs during open-heart surgery or cardiac transplantati0n: Interesting evidence has been presented to Suggest that oxidant stress may be an important contributor to tissue injury under such circumstances and that agents, such as N-acetylcysteine and superoxide dismutase, provide a novel and safe means of reducing these problems. There has been discussion of reperfusion-indueed arrhythmias that may occur following brief periods of ischemia and may be potentially lethal. The possibility that such arrhythmias may contribute toWard sudden cardiac death has been addressed and it has become clear that there are data to indicate that oxidant stress may be one of a number of factors able to increase the vulnerability of the heart to ~uch arrhythmias. We have observed a reduction in ~ such arrhythmias with N-acetylcysteine and other antioxidants [5,6]. The problems of mieroeireulation and the norefl0W phenomenon have been discussed along with the possibility that antioxidant therapy may