Short‐Term, Weight‐Adjusted Colchicine to Prevent Post‐CABG Arrhythmias: A Randomized, Double‐Blind, Controlled Trial

ABSTRACT Background Postoperative arrhythmias are common after coronary artery bypass graft (CABG) surgery and are linked to adverse outcomes. Colchicine, an anti‐inflammatory agent, has shown inconsistent results in prior studies, possibly due to dosing and timing variations. Objectives To evaluate the efficacy and safety of short‐term, weight‐adjusted colchicine initiated preoperatively for preventing postoperative arrhythmias after CABG. Methods In this randomized, double‐blind, placebo‐controlled trial, 172 adults scheduled for on‐pump CABG received colchicine or placebo. The regimen included a preoperative loading dose (1 mg twice daily) followed by a weight‐based maintenance dose (0.5 mg daily if 48 h) POAF, other arrhythmias, inflammatory markers (CRP, ESR), length of stay, and adverse events. Results Of 163 analyzed patients (81 colchicine, 82 placebo), POAF incidence was significantly lower in the colchicine group (17.3% vs. 46.3%; RR 0.37, 95% CI 0.21–0.66; p < 0.001), with an absolute risk reduction of 29.0% and number needed to treat (NNT) of 4. Colchicine reduced both early and late POAF ( p < 0.001 and p = 0.002). No significant reduction was seen in other arrhythmias. Gastrointestinal events, primarily diarrhea, were more common with colchicine (25.9% vs. 8.5%, p = 0.003), but were manageable and without serious adverse events. Conclusion Short‐term perioperative weight‐adjusted colchicine is effective and safe for preventing POAF after CABG, with a low NNT and manageable side effects, though it did not significantly affect other arrhythmias. Trial Registration Iranian Registry of Clinical Trials, IRCT20200328046886N6