Postoperative atrial fibrillation (POAF) is common after cardiac surgery and is associated with adverse outcomes. Standard-dose colchicine could reduce POAF incidence but is limited by poor tolerability. Low-dose colchicine (0.5 mg daily) is recommended for secondary prevention in coronary artery disease with a favourable safety profile.

To compare the incidence of POAF following coronary artery bypass grafting (CABG) between patients who received low-dose colchicine and those managed with standard care.

COLPOAF is an observational, retrospective, before–after, single-centre study conducted in a tertiary care hospital in France. A total of 206 patients who underwent CABG between November 2024 and January 2026 (treated with low-dose colchicine) were compared with a historical control group of 244 patients operated on between May 2023 and July 2024 (without colchicine). The primary efficacy endpoint was the incidence of POAF between postoperative day 3 and hospital discharge.

Baseline characteristics were well balanced between the two groups. POAF occurred in 23 patients (11.2%) in the colchicine group and 29 patients (11.9%) in the standard care group, with a hazard ratio of 0.92 (95% confidence interval 0.53–1.59; P = 0.76). Gastrointestinal adverse events were more frequent with colchicine (7.8 vs. 2.5%), leading to drug discontinuation in 12 patients (5.8%). No major adverse events were attributed to colchicine. C-reactive protein levels were significantly lower in the colchicine group.

Low-dose colchicine was not significantly associated with a reduction in POAF after CABG. The overall safety profile remained acceptable with no severe treatment-related complications.