Atrial fibrillation activation patterns predict freedom from arrhythmias after catheter ablation: utility of ExTRa mapping™

BACKGROUND: Mechanisms underlying atrial fibrillation (AF) are widely complex and vary tremendously among individuals. OBJECTIVES: This retrospective study aimed to investigate the association between AF activation patterns and clinical outcomes post-ablation. METHODS: Fifty-five AF patients (64.0 ± 12.9 years; 41 men; 17 paroxysmal) underwent bi-atrial endocardial driver mapping during AF pre-ablation with a real-time phase mapping system (ExTRa Mapping). The nonpassively activated ratio (%NP) of meandering rotors and multiple wavelets relative to the recording time was evaluated in 26 atrial segments [15 in the left atrium (LA) and 11 in the right atrium]. Irrespective of the mapping results, all patients underwent standard AF ablation via cryoballoons and/or radiofrequency catheters. RESULTS: In a median follow-up interval of 27(14–30) months, 69.1% of patients were free from recurrent arrhythmias and antiarrhythmic drugs at one year post-procedure. Patients with recurrent AF were more likely to have non-paroxysmal AF, a significantly larger LA size, and higher LA maximal %NP(LA(max)%NP) and LA anterior wall %NP(LAAW%NP) than those without recurrent AF. A multivariate Cox regression analysis showed that both an LA(max)%NP (hazard ratio [HR] = 1.075; 95% confidence interval [CI] = 1.02–1.14, p = 0.012) and LAAW%NP (HR = 1.061; 95% CI = 1.01–1.11, p = 0.013) were independent predictors of atrial arrhythmia recurrence. The optimal cutoff points for the LA(max)%NP and LAAW%NP for predicting AF recurrence were 64.5% and 60.0%, respectively. A Kaplan-Meier analysis demonstrated that both an LA(max)%NP > 64.5% (p = 0.0062) and LAAW%NP > 60.0% (p = 0.014) were associated with more frequent AF recurrences. CONCLUSION: Baseline AF activation pattern mapping may aid in predicting freedom from arrhythmias after standard AF ablation procedures.