PO-01-169 CLINICAL APPLICATION OF A NOVEL 31MM CRYOBALLOON FOR PULMONARY VEIN ISOLATION FOR PAROXYSMAL ATRIAL FIBRILLATION: PROCEDURAL DATA FROM THE FIT ARM OF FROZEN AF

Abstract

Cryoablation of pulmonary veins (PV)s to treat paroxysmal atrial fibrillation (PAF) is well established, however there are limited choices in balloon sizes for cryoablation. Data have recently been collected on a new cryoballoon system with novel capability to deliver cryoablation in a standard 28mm diameter balloon or an expanded 31mm diameter, using the same catheter. Demonstrate the clinical utility of an expandable diameter cryoballoon, and discuss the potential advantages for occlusion, antral positioning, and lesion size. As part of the FROZEN AF Trial (NCT04133168) 50 patients received PVI ablation to treat PAF with a cryoballon capable of ablation at 28mm or 31mm. Follow-up is continuing, but we present procedural data and clinical application of this balloon. The extension arm of the FROZEN AF trial (NCT04133168) included 50 pts, 46% female and aged 64±13 years, indicated for PV isolation for treatment of PAF. Acute isolation was successful in all pts. Average procedure time was 101±59 min, with LA dwell of 51 min, and fluoroscopy of 7 min. General anesthesia was used in all patients, and the majority (49/50) underwent a single transeptal puncture. The novel 31mm configuration was used in 65% of ablations. In the 198 ablations performed at 31mm, 97.5% achieved a Grade 3 or 4 occlusion. Average nadir temperature was -54.89°C, and average TTI was 44s. In PVs where the first ablation was performed at 31mm the single shot isolation rate was significantly higher than in PVs where the first ablation was performed at 28mm. Data by PV are listed in Table 1. Notably, there was a low rate of phrenic nerve impairment, with only 1 instance of transient paralysis which resolved prior to discharge. Additionally, in a subset of pts at a single center, occlusion was assessed at both 28mm and 31mm, Figure 1. Preliminary landmark-based analysis of a subset of veins suggests that inflation to 31mm results in a marked antral shift of balloon position. The combination of maneuverability and variable size may make this balloon particularly useful in addressing challenges resulting from patient-to-patient variability in PV size and geometry. In particular, the choice between 28 and 31mm diameter in a single device may facilitate obtaining good occlusion, and the more antral positioning of a large balloon may give physicians more discretion as to the size and location of PVI lesions. As, the FROZEN AF trial is ongoing, long-term results in these patients are awaited.Tabled 1Usage, Occlusion and Single Shot Isolation rate of 28 and 31mm Balloon Sizesn Grade 4 Occlusion / N Total Ablation (%)n Single Shot Isolation / N PV (%)Pulmonary Vein28mm31mm28mm31mmLeft superior (LSPV)18 / 23 (78.3)41 / 45 (91.1)2/8 (25%)19/34 (55.9%)Left inferior (LIPV)17 / 19 (89.5)29 / 38 (76.3)4/12 (33.3%)23/30 (76.7%)Left common (LCPV)5 / 7 (71.4)6 / 19 (31.6)0/0 (%)1/8 (12.5%)Left middle (LMPV)1 / 1 (100)-1/1 (100%)0/0 (%)Right superior (RSPV)9 / 18 (50)49 / 56 (87.5)1/5 (20%)27/43 (62.8%)Right inferior (RIPV)21 / 38 (58.3)33 / 37 (89.2)10/24 (41.7%)17/24 (70.8%)Right common (RCPV)1 / 3 (33.3)2 / 3 (66.7)0/1 (0%)0/1 (0%)Total72 / 109 (67.3)160 / 198 (80.8)18/51 (35.3%)87/140 (62.1%)Single shot success in veins where first ablation was performed with specified balloon size. Only ablations with duration > 60s included in ablation counts Open table in a new tab