Colchicine in addition to usual care for acute pericarditis with classical ECG changes after catheter ablation for cardiac arrhythmias

Background Acute pericarditis is a complication associated with radiofrequency or cryo-energy catheter ablation (CA) for arrhythmias and may be accompany pericardial effusion. A frequent complication of acute pericarditis is the onset of arrhythmias. While colchicine has demonstrated both anti-inflammatory and anti-arrhythmic effects in acute pericarditis, its efficacy in cases specifically developing post-CA remains unknown. The purpose of this study is to determine whether colchicine administration after the diagnosis of acute pericarditis due to CA is associated with a reduction in the recurrence rate of arrhythmias. Methods Patients who developed acute pericarditis after CA for arrhythmias were retrospectively included in this study. Following the CA procedure, a group of patients was prescribed 0.5 mg of colchicine twice daily for 14 days at the operator's discretion, in addition to usual care. The primary outcome was freedom from arrhythmias within 12 months. Secondary outcomes included signs of pericarditis, recurrence of pericardial effusion, and the incidence of constrictive pericarditis. Results Among the 75 consecutively enrolled patients, acute pericarditis occurred after: pulmonary vein isolation (n = 50), endocardial ventricular tachycardia ablation (n = 18), right outflow premature ventricular contraction ablation (n = 5), and atrioventricular nodal re-entrant tachycardia ablation (n = 2). During a median follow-up of 365.0 days (IQR 333.0–420.0 days), freedom from any arrhythmia (regardless of anti-arrhythmic drug use) was similar between groups (76.2% in the colchicine group vs. 74.1% in the usual care group; log-rank p = 0.93). Univariate analysis showed that colchicine use was not associated with a lower risk of arrhythmia recurrence. No cases of recurrent pericarditis or constrictive pericarditis were observed in either group during the follow-up period. Conclusion Colchicine, when added to usual care, doesn't appear associated with improved clinical outcomes in patients who developed acute pericarditis following CA for arrhythmias. Clinical trial number: UD5684993756.