Determinants of AF burden reduction as indicator of successful catheter ablation of atrial fibrillation: data of the ISOLATION study
Z Habibi, D M V Verhaert, O F Ozgul, E Sandgren, B J M Hermans, S Philippens, S M Chaldoupi, B Maesen, A J Isaacs, S W Westra, R Nijveldt, S Zeemering, K Vernooy, D Linz, U SchottenAbstract
Background
Data on reduction of atrial fibrillation (AF) burden as indicator of successful catheter ablation are still scarce. Identifying patients with AF burden reduction after catheter ablation could optimize rhythm-control strategies and patient selection.
Purpose
To assess the degree of AF burden reduction and its association with clinical and procedural parameters in patients undergoing catheter ablation for AF.
Methods
In 290 consecutive patients scheduled for AF ablation in the ISOLATION study, AF burden was
estimated by the number of days with detected AF divided by the total number of days where intermittent rhythm monitoring was used. For pre-procedural rhythm monitoring, patient-operated single lead ECGs devices (3 times daily for 4 weeks) were used. For post-procedural rhythm monitoring, a smartphone photoplethysmography-based application was used (3 times daily for 1 week at 3, 6, and 12 months after ablation). Responders were defined as patients with zero percent post-procedural AF burden or ≥75% reduction in AF burden compared with pre-procedural burden.
Results
Among 290 patients (mean age 64±9 years; 33% female), 194 (67%) had paroxysmal AF and 96 (33%) persistent AF. The median pre-procedural AF burden was 16.7% (IQR 0–35.4) in paroxysmal and 74.0% (IQR 0–93.4) in persistent AF. After AF ablation, the median AF burden was 0% (IQR 0–0) in paroxysmal and 0% (IQR 0–19.1) in persistent AF patients. The pre- and post-procedural AF burden per patient, stratified by paroxysmal and persistent AF, is shown in Figure 1. Out of 290 patients, 232 were responders to AF ablation (71% had paroxysmal AF and 29% persistent AF). A post-ablation AF burden of 0% was observed in 154 (79.4%) paroxysmal and 61 (63.5%) persistent AF patients. Importantly, out of the 95 (33%) patients with recurrences of AF, 37 (38.9%) were responders to AF ablation.
Pre-ablation AF burden (OR 0.93 95%CI [0.86-0.99] per 10%), age (OR 0.96 95%CI [0.93-0.98] per year), chronic obstructive pulmonary disease (COPD) (OR 0.30 [0.17 – 0.98]) and diabetes mellitus (OR 0.41 95%CI [0.17 – 0.98]) emerged as independent predictors of responding to ablation for 12 months follow-up.
Conclusion
Post-procedural AF burden estimated by 3 times daily for 1 week at 3, 6, and 12 months is very low in most patients undergoing AF ablation. A large percentage of patients with recurrences after AF ablation (38.9%) actually show an AF burden reduction of ≥ 75%. Lower pre-ablation AF burden, younger age, not having COPD and diabetes mellitus are independently associated with responding to AF ablation. Incorporating estimated AF burden into pre-procedural assessment may help identify patients who benefit most from AF ablation, and AF burden reduction could serve as a relevant endpoint in future ablation trials.Figure 1.Pre- and post-ablation burden