Perioperative colchicine increases hospital-acquired infections without reducing major cardiovascular complications in patients undergoing coronary artery bypass grafting after acute coronary syndrome

Background/Introduction Patients undergoing coronary artery bypass grafting (CABG) after an acute coronary syndrome (ACS) face a severe inflammatory response driven by the combination of the acute ischaemic event and surgical trauma. Although colchicine has been widely studied in stable coronary disease, its efficacy and safety in this highly inflammatory perioperative setting remain unknown. Purpose To evaluate whether perioperative colchicine administration reduces periprocedural myocardial infarction, post-operative atrial fibrillation, and post-pericardiotomy syndrome in patients with ACS undergoing CABG. Methods In this investigator-initiated, randomised, open-label, blinded-endpoint trial, 100 patients with ACS referred for CABG were randomised in a 1:1 ratio to receive either colchicine (0.5 mg twice daily) or standard of care. Treatment commenced pre-operatively and continued for 30 days after hospital discharge. The primary efficacy endpoint was a composite of periprocedural myocardial infarction (Type 5), post-operative atrial fibrillation, and post-pericardiotomy syndrome, evaluated throughout the follow-up period. Safety endpoints included the incidence of hospital-acquired infections. All clinical events were adjudicated by an independent blinded committee. Results The median age of the 100 randomised patients was 62 years. The primary composite endpoint occurred in 42.0% of patients in the colchicine group and 46.0% in the control group (hazard ratio [HR] 1.00; 95% confidence interval [CI] 0.54-1.84; p=0.995). There were no significant differences in the individual components of the primary endpoint, including periprocedural myocardial infarction (28.0% vs. 28.0%), post-operative atrial fibrillation (20.0% vs. 24.0%), and post-pericardiotomy syndrome (10.0% vs. 22.0%). Conversely, the colchicine group exhibited a significantly higher incidence of hospital-acquired infections compared with the control group (26.0% vs. 10.0%; HR 3.47; 95% CI 1.19-10.12; p=0.023). Serial laboratory analysis revealed that colchicine induced early intravascular neutrophil retention, correlating temporally with this increased infectious vulnerability. Conclusion(s) In patients with ACS undergoing CABG, perioperative colchicine administration did not reduce the incidence of periprocedural myocardial infarction, post-operative atrial fibrillation, or post-pericardiotomy syndrome. Furthermore, the intervention significantly increased the risk of hospital-acquired infections.