Cardioprotective Effects of Melatonin in Patients Undergoing PPCI

Background: One of the pitfalls of primary percutaneous coronary intervention (PPCI) is myocardial reperfusion injury caused by several pathophysiological mechanisms. Melatonin has been shown to be effective against this condition in various organs. Some of the biological effects of melatonin are associated with its capability to scavenge free radicals and reinforce the activity of antioxidant enzymes. Methods: The study population included 128 patients admitted with a diagnosis of acute ST-elevation myocardial infarction (STEMI) to the Emergency Department of Modarres Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran, who subsequently underwent PPCI. The patients were randomly assigned to two groups, each consisting of 64 cases, with those receiving 3 mg of melatonin in the emergency department before adding PPCI to the standard treatment (test group) and those receiving the standard therapy alone (control group). The myocardial blush grade (MBG) and thrombolysis in myocardial infarction frame count were assessed visually on the angiogram to evaluate microvascular integrity. Results: In the study as a whole and in subgroup analysis, the MBG showed a significant difference with melatonin prescription (2.8 ± 0.3 and 2.3 ± 0.7 in the test and control groups, respectively; P < 0.001). In patients with coronary risk factors, no difference was observed between the two groups. Nevertheless, melatonin significantly improved the MBG in patients without such risk factors. Melatonin had significant protective effects in both the right coronary and left anterior descending culprit arteries. Conclusions: This study demonstrated the effect of melatonin on preventing reperfusion injury in patients with STEMI undergoing PPCI.