Effect of Low-dose ColchiciNe on the InciDence of Atrial Fibrillation in Open Heart Surgery Patients: END-AF Low Dose Trial

Background Studies using 1 mg of colchicine to prevent postoperative atrial fibrillation (POAF) reported conflicting results. Moreover, colchicine was associated with significant gastrointestinal (GI) side effects. This study examined whether low-dose colchicine effectively prevents POAF and whether low-dose therapy is associated with lower rates of colchicine-induced GI side effects. Methods In this prospective, randomized, double-blind, placebo-controlled study, consecutive adult patients admitted for elective cardiac surgeries randomly received a 1-mg dose of colchicine (n = 81) or placebo (n = 71) orally 12 to 24 hours before surgery followed by a daily dose of 0.5 mg until hospital discharge. The primary efficacy endpoint was the development of at least one episode of POAF of ≥5 minutes. The primary safety endpoint was the development of adverse events, especially diarrhea. Results The in-hospital mortality rate was 3.9%. POAF occurred in 13 patients (16.1%) in the colchicine group and 13 patients (18.3%) in the placebo group (odds ratio 0.85 [95% Confidence Interval = 0.37−1.99]). Diarrhea occurred in two patients in each group and necessitated treatment discontinuation in one patient in each group. Conclusion Low-dose colchicine did not prevent POAF in patients undergoing cardiac surgery. These results should be interpreted cautiously because of the small sample size and early study termination. ClinicalTrials.gov Unique Identifier number: NCT03015831