Influence of balloon temperature and time to pulmonary vein isolation on acute pulmonary vein reconnection and clinical outcomes after cryoballoon ablation of atrial fibrillation

Abstract

BackgroundLimited data exist on indicators of durable pulmonary vein isolation (PVI) undergoing cryoballoon ablation (CBA) for atrial fibrillation (AF). We investigated whether balloon temperature and time to PVI can be used to predict early PV reconduction (EPVR), including residual PV conduction and adenosine triphosphate‐induced dormant conduction and the relation between touch‐up ablation of EPVR sites and mid‐term recurrence of AF.MethodsWe obtained procedural and outcome data from the records of 130 consecutive patients who underwent CBA and followed up for 13.4 months.Results EPVR was identified in 86 (17%) PVs of 61 (47%) patients. Balloon temperatures during 30 seconds (−27 ± 5.7°C vs −31 ± 5.5°C), 60 seconds (−36 ± 5.6°C vs −41 ± 5.4°C), and at the nadir point (−41 ± 7.4°C vs −49 ± 7.0°C) were significantly higher, and the time to PVI was longer (90 ± 50 seconds vs 52 ± 29 seconds) in PVs with EPVR than in those without (P < 0.0001 for all). Among PVs without EPVR, the time to PVI was longer and balloon temperature was lower for the left superior pulmonary vein/ right inferior pulmonary vein (LSPV/RIPV) than for the right superior pulmonary vein/left inferior pulmonary vein (RSPV/LIPV) (time: 60 ± 25/73 ± 37 seconds vs 41 ± 31/45 ± 20 seconds, P < 0.0001) (temp: −39.2 ± 11.3/−39.4 ± 8.3°C vs −33.8 ± 10.6/−33.6 ± 6.8°C, P = 0.0023). AF recurrence rates were equivalent between patients with and without EPVR (13% [8/69] vs 15% [9/61], P = 0.845).ConclusionsCryoballoon temperature and time to PVI appear to be useful in predicting durable PVI, that is, prevention of EPVR, but the balloon temperature and time required for PVI differ between PVs. Although EPVR does not predict AF recurrence, high success rates can be expected when touch‐up ablation of EPVR sites is performed.

Optimal diameter of the pulmonary vein ostium for second‐generation 28‐mm cryoballoon ablation of atrial fibrillation

“…To successfully isolate the PV by CBA, it is important to prevent any gap formation around the PV ablation region, and a complete obstruction of the PV with the balloon to prevent leakage of contrast medium and to acquire a sufficient cooling temperature is essential . In our previous study, a temperature below −44°C was considered appropriate for the NBT to prevent an EPVR during the second‐generation 28‐mm CBA, which is well in line with the other previous reports . Therefore, for the upper limit of the NBT for a successful PV isolation by CBA, the index below −44°C used in this study may have been valid.…”

“…8,9 In our previous study, a temperature below −44 • C was considered appropriate for the NBT to prevent an EPVR during the second-generation 28-mm F I G U R E 3 ROC curves of the PVmax diameter, PVmin diameter, and PV elliptical area for the prediction of the minimum and maximum optimal NBTs. The best cutoff values of the PVmax for predicting an NBT <− 44 • C were >19 mm (sensitivity 42%, specificity 83%; A), >14 mm for a PVmin predicting an NBT <− 44 • C (sensitivity 60%, specificity 72%; B), >186.83 mm 2 for an elliptical area predicting an NBT <− 44 • C (sensitivity 59%, specificity 74%; C), >21 mm for a PVmax predicting an NBT <− 60 • C (sensitivity 73%, specificity 82%; D), >16 mm for a PVmin predicting an NBT <− 60 • C (sensitivity 82%, specificity 72%; E), and >254.34 mm 2 for an elliptical area predicting an NBT <− 60 • C (sensitivity 73%, specificity 81%; F) Abbreviations: NBT, nadir balloon temperature; PV, pulmonary vein; PVmax, the maximum pulmonary vein ostium diameter; PVmin, the minimum pulmonary vein ostium diameter; ROC, receiver operating characteristic CBA, 12 which is well in line with the other previous reports. [4][5][6]24,25 Therefore, for the upper limit of the NBT for a successful PV isolation by CBA, the index below −44 • C used in this study may have been valid.…”

“…We previously reported that the effective nadir balloon temperature (NBT) was <− 44 • C based on the cutoff receiver operating characteristic (ROC) curve values to prevent an early PV reconduction (EPVR). 12 In contrast, when the PV or left atrial (LA) diameter is large, the cryoballoon goes deep into the PV and causes excessive cooling below −55 to −60 • C, resulting in procedural complications such as PV stenosis or phrenic nerve injury. 11,[13][14][15] Nonetheless, the relationship of the PV diameter and LA diameter to the cooling temperatures during CBA has not been fully investigated.…”

Current Status and Clinical Outcomes of Oral Anticoagulant Discontinuation After Ablation for Atrial Fibrillation in Japan ― Findings From the AF Frontier Ablation Registry ―

“…Generally, OACs were continued, but this varied from institution to institution, and the procedure itself was performed according to each institution's particular protocol but generally as previously described. 18,19 Extensive encircling PVI was guided by a circular mapping catheter or multiple-electrode catheter and a 3D mapping system. The ablation catheter was an irrigated-tip contact force (CF) sensing catheter or irrigated-tip standard non-CF sensing catheter, depending on the hospital's preference or type of catheter available at the time of the procedure.…”

Cryoballoon Ablation for Patients With Paroxysmal Atrial Fibrillation

“…39,40 After identifying the time to PV isolation (TTI) as an essential indicator of durable PV isolation, the latest ablation strategies have been implemented the individual TTI. 41 The weakness of CB2, however, is that TTI could be less arrhythmogenic and thrombogenic than the ragged, indistinct lesions associated with RFCA. 33 The use of cryoablation for PV isolation may offer certain advantages.…”