Efficacy of colchicine versus placebo for the treatment of pericardial effusion after open-heart surgery: A randomized, placebo-controlled trial

Background Pericardial effusion (PE), a common complication after open-heart surgery, accounts for 50% to 85% of patients. Although reversible in most of the cases, it could be life threatening in the occurrence of tamponade in large effusions. We aimed to determine the therapeutic efficacy of colchicine on PE after open-heart surgery. Methods The study is a prospective, randomized, triple-blind, placebo-controlled single-center trial at Tehran Heart Center. A total of 149 patients with mild or moderate PE in transthoracic echocardiography were randomly assigned to receive 1 mg/d colchicine (n = 74) or 1 tablet of placebo (n = 75) for 2 weeks and then underwent follow-up echocardiography. Results Baseline and clinical characteristics were not significantly different between the 2 study groups except for age (P = .02) and graft numbers (P = .005). There was no significant difference in pretreatment and posttreatment PE sizes between the 2 study groups (P = .440 and .844, respectively). Median (25th-75th percentiles) of effusion changes was 5 mm (1-7.6 mm) in the colchicine group and 5 mm (1-6.6 mm) in the placebo group (P = .932). Intervention had no significant impact on pretreatment and posttreatment effusion values and changes in isolated coronary artery bypass graft surgery patients (P = .607, .539, and .628, respectively). After adjustment for possible confounders, there was still no significant difference in postoperative PE between the 2 study groups (t = -0.285, P = .776). Conclusion We concluded that prescription of colchicine does not seem to be effective in treatment of asymptomatic postoperative PE. This could be justified in case that the etiology of most of the PEs might be contribution of noninflammatory factors which are better to be dealt with observational approaches.