Recurrence is a common problem after catheter ablation for atrial fibrillation, affecting at least one out of three patients. Inflammation due to the procedure may contribute to pulmonary vein reconnection and, thus, failure of catheter ablation.

This pilot study will assess whether a randomized, placebo-controlled, double-blind trial investigating a 10-day treatment with colchicine, a potent anti-inflammatory drug, to improve patient relevant outcomes after catheter ablation for atrial fibrillation is feasible.

Inclusion Criteria:

1. Age ≥ 18 years
2. Symptomatic atrial fibrillation and planned catheter-guided first or repeat ablation (pulmonary vein isolation) for atrial fibrillation (radiofrequency or cryoablation energy; concomitant ablation of the cavotricuspid isthmus and other lesions left at the discretion of the treating physician)
3. Written informed consent

Exclusion Criteria:

1. Ablation for left atrial tachycardia or isthmus-dependent atrial flutter only (i.e. without pulmonary vein isolation)
2. Administration of a strong inhibitor of CYP3A4 or p-gp (clarithromycin, erythromycin, telithromycin, cyclosporine, ketoconazole or itraconazole)
3. Known hypersensitivity to colchicine
4. Serious gastrointestinal disease (severe gastritis or diarrhea)
5. Clinically overt hepatic disease
6. Severe renal disease (eGFR< 30ml/min/1.73m2)
7. Clinically significant blood dyscrasia (e.g., myelodysplasia)
8. Absolute indication for or ongoing treatment with colchicine
9. Pregnant or breastfeeding women, or women of child-bearing potential who do not use a highly effective form of birth control