Usefulness of Early Treatment With Melatonin to Reduce Infarct Size in Patients With ST-Segment Elevation Myocardial Infarction Receiving Percutaneous Coronary Intervention (From the MARIA [Melatonin Adjunct in the acute myocaRdial Infarction treated with Angioplasty] Trial)

Abstract Melatonin, an endogenously-produced hormone, might potentially limit the ischemia-reperfusion injury and improve the efficacy of mechanical reperfusion with primary percutaneous coronary intervention (pPCI) in ST-segment elevation myocardial infarction (STEMI). This study was aimed to evaluate whether the treatment effect of melatonin therapy among patients with STEMI is influenced by the time to administration. We performed a post-hoc analysis of the MARIA (Melatonin Adjunct in the acute myocaRdial Infarction treated with Angioplasty) [NCT00640094], which randomized STEMI patients to melatonin (intravenous and intracoronary bolus) or placebo during pPCI. Randomized patients were divided into tertiles according to symptoms onset to balloon time: 1st tertile (136 ± 23 min), 2nd tertile (196 ± 19 min) and 3rd tertile (249 ± 41 min). Magnetic resonance imaging was performed within 1 week after pPCI. A total of 146 patients presenting with STEMI within 360 min of chest pain onset were randomly allocated to intravenous and intracoronary melatonin or placebo during pPCI. In the first tertile, the infarct size was significantly smaller in the melatonin-treated individuals compared with placebo (14.6 ± 14.2 versus 24.9 ± 9.0 %; p =0.003). Contrariwise, treatment with melatonin was associated with a larger infarct size in the group of patients included in the third tertile (20.5 ± 8.7 versus 11.2 ± 5.2%; p = 0.001), resulting in a significant interaction ( p =0.001).In conclusion, the administration of melatonin in patients with STEMI who presented early after symptom onset was associated with a significant reduction in the infarct size after pPCI.