Effects of Melatonin on Postoperative Delirium After PCI in Elderly Patients: A Randomized, Single-Center, Double-Blind, Placebo-Controlled Trial

Experimental evidence has indicated the benefits of melatonin (Mel) for the treatment of delirium. Clinical trials had no definite conclusions concerning Mel on delirium after percutaneous transluminal coronary intervention (PCI) in elderly patients. The present study explored whether acute Mel treatment could reduce the incidence of delirium.This trial enrolled patients over the age of 60, who were admitted to intensive care units (ICUs) after PCI. A computer-generated randomization sequence (in a 1:1 ratio) was used to randomly assign patients to receive Mel (3 mg/day) or placebo once daily for up to 7 days. The primary endpoint was the incidence of delirium, assessed twice daily with the Confusion Assessment Method (CAM) during the first 7 postoperative days. Analyses were performed using intention-to-treat and safety populations.A total of 297 patients randomly were assigned to receive either placebo (N = 149) or Mel (N = 148). The incidence of postoperative delirium was significantly lower in the Mel group than in the placebo group (27.0% vs. 39.6%, respectively, P = 0.02). There was no significant difference between 30-day all-cause mortality (12.2% vs. 14.1%, P = 0.62) and drug reactions (0 vs. 2.0%, P = 0.25). The length of stay and hospitalization costs in the Mel group were significantly decreased compared with those in the placebo group (P > 0.05).The current study suggests that Mel is safe and effective in the treatment of delirium after PCI. Further investigation is necessary to fully understand the potential usefulness of Mel in older patients via larger randomized, multicenter, double-blind, and placebo-controlled trials.