Abstract
BACKGROUND: The 2024 EHRA/HRS/APHRS/LAHRS expert consensus statement proposed an 8-week "blanking period" for clinical trials involving catheter ablation of atrial fibrillation (AF), in which recurrences are not seen as a failure of treatment. However, the relationship between early recurrence of atrial arrhythmia and clinical events during the first 8 weeks following catheter ablation is not well defined. PURPOSE: To study the association between recurrence of atrial arrhythmia in the first 14 days following catheter ablation of AF and healthcare utilization in the first 8 weeks following ablation. METHODS: We analyzed prospectively collected data from participants enrolled in the IMPROVE-PVI randomized trial testing colchicine 0.6 mg twice daily vs. placebo for 10 days following catheter ablation of AF. All participants received a 14-day Holter immediately following ablation. Recurrence of atrial arrhythmia was defined as Holter-documented AF, atrial flutter, or atrial tachycardia >30 seconds, and healthcare utilization was defined as any of emergency department visit, cardiovascular hospitalization, cardioversion, or repeat ablation. Blinded adjudicators assessed arrhythmias and outcomes. We built regression models to estimate the association between early recurrence of atrial arrhythmia and healthcare utilization. RESULTS: We analyzed data from 194 patients who wore a Holter immediately following catheter ablation of AF (median age 61 years, 22% female, 70% first procedure). The median HATCH score (hypertension: 1, age≥75 years: 1, transient ischemic attack or stroke: 2, chronic obstructive pulmonary disease [COPD]: 1, heart failure: 2) was 1 (interquartile [IQR] range, 0-1; range, 0-5), and 144 patients (74%) were discharged on an antiarrhythmic drug. During a median monitoring duration of 13 days, 61 patients (31%) had recurrent atrial arrhythmia. A total of 25 patients (13%) had a healthcare utilization event in the first 8 weeks following catheter ablation. Adjusted for the HATCH score, early recurrence of atrial arrhythmia was significantly associated with healthcare utilization (adjusted odds ratio 6.21, 95% confidence interval 2.49-15.51), as was higher burden of AF (per 1%-increase in AF burden, adjusted odds ratio 1.03, 95% confidence interval 1.01-1.05). Colchicine did not reduce early recurrence of atrial arrhythmia (hazard ratio 0.98, 95% confidence interval 0.59-1.61), nor did it reduce healthcare utilization within 8 weeks of ablation (hazard ratio 0.92, 95% confidence interval 0.42-2.02). CONCLUSIONS: Nearly 1 in 3 patients had early recurrence of atrial arrhythmia in the first 14 days following catheter ablation of AF. More than 1 in 8 patients experienced a clinical meaningful event during the 8-week "blanking period" following catheter ablation, which was largely driven by early recurrence of atrial arrhythmia. Colchicine reduced neither early recurrence of atrial arrhythmia nor healthcare utilization.