Pre-clinical and clinical studies have demonstrated that melatonin has cardio-protection effects. Melatonin has anti-inflammatory, antioxidant, antihypertensive, antithrombotic and antilipaemic properties, which plays important roles in a variety of cardiovascular pathophysiologic processes. Nocturnal melatonin levels decreased after AMI, and lower serum melatonin concentrations after AMI are associated with more heart failure and cardiac death and left ventricular remodeling. Moreover in women with increased BMI, lower melatonin secretion is associated with higher risks of MI. Early-morning blood collection is easier in clinical practice. Therefore, the investigators carried out a cohort study to evaluate the prognostic value of plasma soluble melatonin in hospitalized patients with acute myocardial infarction (AMI).

Inclusion Criteria:

• consecutive patients of acute AMI come to department of cardiology, 301 hospital (Beijing, China),absent of cardiogenic shock, and survival for at least 24 h after percutaneous coronary intervention treatment.

Exclusion Criteria:

• patients with autoimmune diseases, collagen tissue diseases, drug addiction, radiotherapy, patients receiving immunosuppressive treatment, taking sedatives, antiepileptic drugs, tricyclic antidepressants or any medication known to influence melatonin metabolism, psychiatric sleeping disorders, shift workers, and subjects with jet-lag syndrome

A single center study on PCI-treated myocardial infarction patients