Effects of Melatonin on Reperfusion Injury

Acute myocardial infarction is a major cause of mortality and morbidity. Primary percutaneous coronary intervention (pPCI) is currently the most effective treatment strategy in acute myocardial infarction. However, a sizable number of patients fail to restore optimal myocardial reperfusion, mostly because of the 'no-reflow' phenomenon. Melatonin is the chief indoleamine produced by the pineal gland, and a well-known antioxidant and free radical scavenger. Several studies have shown that melatonin protects against ischemia/reperfusion injury (IRI). In our previous study, melatonin markedly reduced infarcted area, improved cardiac function and reduced lactate dehydrogenase release in rats. The investigators planned to research the cardioprotective effects of intravenous melatonin administered prior to reperfusion and continued after restoration of coronary blood flow in patients with ST segment elevation myocardial infarction undergoing pPCI.