The feasibility and safety of substrate modification on the left atrial roof area using a cryoballoon in atrial fibrillation ablation

Raise-up technique for the creation of left atrial roof lesion: A useful technique with cryoballoon for persistent atrial fibrillation

INTRODUCTION

Recent studies have reported the efficacy of the cryoballoon (CB)-guided left atrial roof block line (LARB) creation in patients with persistent atrial fibrillation (AF). However, it can be technically challenging to attach the balloon to the left atrial (LA) roof due to its anatomical variations. We designed a new procedure called the "Raise-up Technique," which may facilitate the firm adhesion of the CB to the LA roof during freezing. This study aimed to evaluate the efficacy of the Raise-up technique in LARB creation.

METHODS AND RESULTS

In total, 100 consecutive patients with persistent AF who underwent CB-LARB creation were enrolled. Fifty-seven patients underwent LARB creation using the Raise-up technique (Raise-up group), and the remaining 43 did not use it (control group). The Raise-up technique was performed as follows: An Achieve catheter was inserted as deeply as possible into the upper branch of the right superior pulmonary vein to anchor the CB. The balloon was placed below the targeted site on the LA roof and frozen. When the temperature of the CB reached approximately -10°C and the CB was easier to attach to the LA tissue, the CB was raised and pressed against the LA roof immediately by sheath advancement. Then the balloon could be in firm contact with the target site on the roof. If necessary, additional sheath advancement after sufficient freezing (-20°C to -30°C) was allowed the CB to have more firm and broad contact with the target site. LARB creation without touch-up ablation was achieved in 54 of 57 patients (94.7%) in the Raise-up group and 33 of 43 patients (76.7%) in the control group (p < .05). The lesion size of the LARB in the Raise-up group was significantly larger than that in the control group (15.2 cm2 vs. 12.8 cm2, p < .05). Moreover, the width of the LARB lesion in the Raise-up group was wider than that in the control group (32.0 mm vs. 26.6 mm, p < .05).

CONCLUSION

The Raise-up technique enabled the creation of seamless and thick LARB lesions with a single stroke. In addition, the CB-LARB lesions created using the Raise-up technique tended to be large, resulting in extensive debulking of the LA posterior wall arrhythmia substrates. In CB ablation for persistent AF, the Raise-up technique can be considered one of the key strategies for LARB creation.

Reablation in Atrial Fibrillation Recurrence and Pulmonary Vein Reconnection: Cryoballoon versus Radiofrequency as Index Ablation Procedures

Pulmonary vein (PV) isolation is a well-established rhythm control therapy in atrial fibrillation (AF). Currently, there is no consensus on which ablation technique to use for the first procedure, cryoballoon (CB) or radiofrequency (RF). A retrospective cohort study was conducted on 1055 patients who underwent a first ablation, to assess both techniques based on the need for reablation. Patients with CB (n = 557) and RF (n = 498) ablations were clinically characterized and the need for reablation during a 30-month follow-up was used as the primary endpoint. Independent variables were analyzed to identify potential predictors. The need for reablation was significantly lower in the CB group than in the RF group (hazard ratio = 0.45 and 95% confident interval = 0.32−0.61; p < 0.001); in both paroxysmal and persistent AF, using a full-adjusted regression Cox model by age, sex, smoking, hypertension, diabetes mellitus, dyslipidemia, severe obstructive sleep apnea, dilated left atrium, persistent AF and early recurrence. RF ablation, dilated left atrium, persistent AF and early recurrence were identified as independent predictors of reablation. In addition, the CB-redo subgroup had a lower PV reconnection than the RF-redo subgroup. In conclusion, CB ablation suggests a reduction in the need for reablation and lower PV reconnection during the follow-up than RF ablation.