We planned to evaluate the effects of melatonin on progression of coronary artery calcification (CAC) in patients with moderate calcified coronary atherosclerosis.

CAC is prevalent in coronary artery disease (CHD), and the extent of CAC predicts cardiovascular risk. The causes of CAC include dysregulated matrix metabolism, epitaxial mineral deposition, inflammation, oxidative stress, and apoptosis. Melatonin is the main indoleamine produced by the pineal gland; it is known recently to have anti-inflammatory, anti-cancer and antioxidant activities. Several studies have shown that melatonin protects against inflammation and apoptosis in vascular calcification. Melatonin also inhibits oxidative stress-induced apoptosis and calcification in endplate chondrocytes. The investigators planned to determine the efficacy of melatonin on progression of coronary artery calcification (CAC) in patients with moderate calcified coronary atherosclerosis. This study may shed light as to whether oral melatonin supplementation can be an adjunct therapy in CAC patients.

Inclusion Criteria:

Patients with a documented Agatston score≥30 and moderate calcified coronary atherosclerosis (<50% diameter lumen narrowing) were eligible for the study.

Exclusion Criteria:

1. unstable angina pectoris
2. symptomatic chronic heart failure and/or left ventricular ejection fraction (EF) <40%
3. atrial fibrillation or other arrhythmias
4. type I diabetes mellitus or uncontrolled type II diabetes mellitus
5. renal failure
6. liver disease
7. gastrointestinal disease that affected absorption