Efficacy of colchicine versus placebo for the treatment of pericardial effusion after open-heart surgery: A randomized, placebo-controlled trial Ali Izadi Amoli, MD, Ali Bozorgi, MD, Azita HajHossein Talasaz, PharmD, BCPS, Abbas Salehi Omran, MD, Seyedeh Hamideh Mortazavi, MD, Arash Jalali, PhD, Shaghayegh Nasirpour, MD, and Yaser Jenab, MD Tehran, Iran 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. (Am Heart J 2015;170:1195-201.) Pericardial effusion (PE) is a common complication after open-heart surgery 1,2 with an incidence range of 50% to 85%. 3 Although most cases of PE are spontaneously reversible, this complication could prove life threatening in some circumstances such as the occurrence of cardiac tamponade in large effusions. 4 Approximately 1% to 2% of patients undergoing open-heart surgery may slowly progress to cardiac tamponade even with no evident symptoms 7 days after the operation. In addition, postoperative PE can lead to readmission and prolonged in-hospital stays and is considered one of the main causes of open-heart surgery morbidities. 1,5 Therefore, early diagnosis and appropriate treatment strategies can reduce post- operative morbidity, improve quality of life, and decrease health care costs. No specific guideline has been released yet for the therapeutic approach to mild and moderate PE after open-heart surgery. In some cases, it is just recom- mended to follow up patients without medication, and in some other, the use of nonsteroidal anti-inflammatory drugs or corticosteroids is preferred. 4-7 However, the efficacy of diclofenac in reducing postoperative PE was questioned in a randomized trial by Meurin et al. 8 Colchicine, inhibitor of microtubules polymerization, 9 has been found effective and safe in the prevention and treatment of recurrent pericarditis. 10-14 Meanwhile, the preventive effects of colchicine in PE after cardiac surgery are noted in previous studies. 1 Nevertheless, to our knowledge, there is a paucity of data on its therapeutic effects, and the available studies have addressed only its preventive impacts. A recent completed randomized trial by Meurin et al 12 showed that 2 weeks' treatment with 1 mg daily colchicine could not significantly reduce the mean PE grade compared to a placebo. There is no doubt From the Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. Conflicts of interest: None. Submitted August 17, 2015; accepted September 26, 2015. Reprint requests: Ali Bozorgi, MD, Assistant Professor of Cardiology, Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. E-mail: abozorgi@tums.ac.ir 0002-8703 © 2015 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.ahj.2015.09.020