High-density mapping in catheter ablation for persistent atrial fibrillation

Abstract

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Abbott Laboratories Background Pulmonary vein isolation (PVI) is an established treatment option for persistent atrial fibrillation (PersAF). Corresponding long-term success rates remain modest however, advancements in high-density (HD) mapping may better identify substrates. The HD grid-style mapping catheter (HD Grid) allows for simultaneous analysis of adjacent orthogonal bipolar signals that may assist in ablation strategy decisions to achieve favorable outcomes in treating PersAF. Objective This was a prospective, multi-center, observational study to quantify and characterize the use of a market-released HD mapping catheter in PersAF subjects. Methods HD Grid was used in PersAF subjects undergoing radiofrequency (RF) ablation across 25 sites to gather data regarding safety, mapping efficiency and quality, ablation strategies, and procedural outcomes. Results 334 PersAF subjects (average age: 64.2 years; 76% male) were enrolled in this study. Types of maps generated included peak-to-peak voltage (78%; 322/413), local activation time (LAT) (11.4%; 47/413), and complex fractionated electrogram (CFE) mean (7.7%; 32/413). Median total mapping points collected and used were 8428.0 (IQR 4845.0-13366.0) and 2099.0 (IQR 1219.0-2947.0), respectively, in a median of 11.0 (IQR 7.3-16.0) minutes per map. Low voltage, scar/fibrosis, and CFE were searched for in 90.4% (302/334), 53.6% (179/334), and 15.9% (53/334) of subjects, respectively. A PVI approach was used in 93.1% of all ablation procedures and 34.1% (114/334) of subjects received PVI plus additional lesions. HD Grid identified signals of interest not identified by the ablation catheter in 80.4% (205/255) of subjects. The total procedure time was 134.3 ± 51.3 minutes with a fluoroscopy time of 14.5 ± 11.3 minutes and RF ablation time of 32.4 ± 29.6 minutes. Of the subjects in atrial fibrillation (AF) (59.6%; 199/334), AF was terminated in 80.4% (160/199). 87.4% (173/198) of subjects were free from recurrent atrial arrhythmias as detected by 48-hour Holter monitoring at 12 months. 13.8% (46/334) of subjects experienced any adverse event through 12 months including 1 death unrelated to the procedure and 1 event deemed related to HD Grid by the investigator. Conclusion This study demonstrated the use of the HD Grid mapping catheter to create detailed maps and to guide ablation strategies to treat PersAF while maintaining an adequate safety profile.