Comparison of ablation outcomes of the second ablation procedure for recurrent atrial fibrillation using an ultra‐high‐resolution mapping system and conventional mappings system

BACKGROUND: The utility of an ultra‐high‐resolution electroanatomical mapping system (UHR‐EAM, Rhythmia) for repeat atrial fibrillation (AF) ablation has not been evaluated. HYPOTHESIS: A second AF ablation procedure performed using UHR‐EAM may demonstrate different outcomes compared with that using a conventional electroanatomical mapping system (C‐EAM, CARTO3). METHOD: This observational study enrolled consecutive patients who underwent a second AF ablation procedure using UHR‐EAM (n = 103) and C‐EAM (n = 153). The second ablation procedure included re‐isolation of reconnected pulmonary veins (PVs) and elimination of clinical or induced non‐PV AF triggers and atrial tachycardia (AT). Other empirical ablations were additionally conducted at the discretion of the operators. RESULTS: Re‐isolation of PVs was achieved in 196 patients who had ≥1 left atrial‐PV reconnection. The elimination rate of AT was higher in the UHR‐EAM group than the C‐EAM group (87% vs 65%, P = .040), while that of non‐PV AF triggers was similar (63% vs 63%, P = 1.00). The UHR‐EAM demonstrated shorter radiofrequency application time (21.8 ± 16.8 vs 28.0 ± 21.3 minutes, P = .017), but longer fluoroscopic time (26.2 ± 12.6 vs 21.4 ± 9.3 minutes, P = .0001). No severe complication developed. The total 1‐year AF/AT‐free survival rates were similar between the two groups (off AADs, 59.2% vs 56.2%, P = .62; on AADs, 65.0% vs 69.3%, P = .49). CONCLUSION: The efficacy and safety outcomes of repeat AF ablation using UHR‐EAM was comparable to those using C‐EAM.