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Abstract Background Left atrial low-voltage areas (LA LVA) measured at time of catheter ablation for atrial fibrillation (AF) have been increasingly recognized as an indicator of atrial fibrosis 1. However, little is known whether first-time catheter ablation outcomes differ between paroxysmal AF (PAF) and persistent AF (PerAF) in patients with higher LA LVA, which may indicate a more advanced substrate independent of clinical subtype. Purpose To evaluate whether outcomes of first-time catheter ablation for AF are dependent on LA LVA rather than PAF vs. PerAF types in a multicenter registry of patients. Methods The Real-world Experience of Catheter Ablation for the Treatment of Symptomatic PAF and PerAF Using Novel Contact Force Technologies registry (REAL-AF) is a prospective, observational multicenter registry of patients undergoing catheter ablation. We evaluated 4181 patients undergoing first-time catheter ablation for both PAF and PerAF to determine AF recurrence within 12 months. Contact maps were created using a 5-spline high-density catheter. LA LVA was calculated using these contact maps based on a bipolar voltage of 0.50 mV. LA LVA was categorized into low (5%) vs. high (≥5%) based on preliminary data. Risk of recurrence was analyzed using Cox proportional hazard models. Results Patients with LA LVA ≥5% who underwent first-time catheter ablation for AF (both PAF and PerAF) experienced a higher risk of AF recurrence within 12 months (Hazard ratio (HR): 1.95, p0.001), see Figure 1. Overall, 82.0% of patients were free of AF in the LA LVA 5% group compared to 69.1% in the LA LVA ≥5% group. This association remained significant in a subpopulation of patients presenting in normal sinus rhythm (N = 2463) at time of ablation (HR: 1.90, p0.001). 12-month ablation outcomes between PAF and PerAF in patients with LA LVA ≥5% (N = 1590) were not statistically significant (71.0% vs 67.3% respectively, HR: 1.15, p=0.30), see Figure 2. Finally, in the LA LVA 5% group (N = 2591), patients with PerAF had a 1.42 times higher risk for AF recurrence within 12 months after catheter ablation (p=0.04). Conclusion This is the largest real-world registry to date demonstrating that LA LVA ≥5% is associated with a higher risk of AF recurrence within 12 months in patients undergoing first-time catheter ablation for AF. Among patients with LA LVA ≥5%, AF recurrence was not associated with AF type. These findings motivate further studies into using LA LVA as a prognostic tool for patients undergoing first-time catheter ablation for AF and using non-invasive methods to assess this in order to stratify patients further.
Nguyen et al. (Wed,) studied this question.