Korean Circulation Journal 대한심장학회지 순환기 Joung B, et al. Korean Circ J. 2018 Dec;48(12):1033-1080. https://doi.org/10.4070/kcj.2018.0339

Posterior wall isolation (PWI) of the left atrium (LA) adjunct to pulmonary vein isolation (PVI) by radiofrequency catheter ablation has shown favourable outcomes in patients with persistent atrial fibrillation (PeAF). This study was sought to investigate the efficacy and safety of additional PWI by cryoballoon ablation (CBA) alone in patients with PeAF. Patients who underwent de novo CBA for PeAF (n = 100) were randomly assigned (1 : 1) to the PVI only group and PVI combined with PWI (PVI+PWI) group. Procedural and clinical outcomes were prospectively compared over a 12-month follow-up. Baseline characteristics, including mean AF duration (56.2 ± 43.2 months) and LA size (48.2 ± 7.7 mm), were well-balanced between the groups. Successful PVI was achieved in all patients. In the PVI+PWI group, complete PWI by CBA was achieved in 31 (62%) patients. The LA indwelling and procedure times were significantly longer in the PVI+PWI group. The complication rates were not different between groups. During a mean follow-up of 457.9 ± 61.8 days, the recurrence rate of atrial tachyarrhythmia was significantly lower in the PVI+PWI group than in the PVI only group (24% vs. 46%; P = 0.035). The recurrence-free survival rate was significantly higher in the PVI+PWI group compared with the PVI only group, irrespective of complete PWI (log-rank P = 0.013). Multivariate analysis showed that adjunctive PWI [hazard ratio (HR) 0.255; P = 0.003] and LA size (HR 1.079; P = 0.014) were independent predictors of clinical recurrence. Compared with PVI only, adjunctive PWI achieved exclusively by CBA resulted in better clinical outcomes without increasing complications in patients with PeAF.

Aims: The formation of radiofrequency lesions depends on the power and duration of ablation, and the contact force (CF). Although high power (HP) creates continuous and transmural lesions, most centres still use 25–30 W for 30–40 s for safety reasons. We evaluated the clinical efficacy and safety of a HP and short-duration (HPSD) strategy for atrial fibrillation (AF) ablation. Methods and results: One hundred and fifty patients [58.2 ± 10.0 years, 48% with paroxysmal AF (PAF)] scheduled for index AF ablation using a CF-sensing catheter were randomly assigned to three groups [30 W, 40 W, and 50 W at ablation sites of anterior, roof, and inferior segments of pulmonary vein (PV) antra and roof line between each upper PV]. In 25–30 W for ≤20 s was applied at posterior wall ablation site in all subjects. Compared with the 30 W and 40 W groups, procedure (P < 0.001) and ablation times (P < 0.001) were shorter and ablation number for PV isolation (P < 0.001) was smaller in the 50 W group. There were no significant differences in the CF and ablation index (AI) among the three groups. There were no significant differences in the procedure-related complication rates. During the 12-month follow-up, AF recurred in 24 (16%) patients with no significant difference among the groups (P = 0.769). In the multivariate analysis, non-PAF [hazard ratio (HR) 2.836, P = 0.045] and AI (HR 0.983, P = 0.001) were independent risk factors for AF recurrence. Conclusion: Radiofrequency ablation with HPSD is a safe and effective strategy with reduced ablation number and shortened procedure time compared to conventional ablation.

The development of intracardiac echocardiography (ICE) has enabled fluoroless atrial fibrillation (AF) ablation using three-dimensional electroanatomical mapping systems. However, fluoroless cryoballoon ablation (CBA) remains challenging, mainly because of the lack of a visual mapping system. Hence, this study aimed to investigate the safety and efficacy of fluoroless CBA for AF under ICE guidance. Patients (n = 100) who underwent CBA for paroxysmal AF were randomly assigned to zero-fluoroscopic (Zero-X) and conventional groups. Intracardiac echocardiography was used to guide the transseptal puncture and catheter and balloon manipulation in all enrolled patients. The patients were prospectively followed for 12 months after CBA. The mean age was 60.4 years, and the left atrial (LA) size was 39.4 mm. Pulmonary vein isolation (PVI) was achieved in all patients. In the Zero-X group, fluoroscopy was used in only one patient because of unstable phrenic nerve capture during right-sided PVI. The procedure time and LA indwelling time in the Zero-X group were not statistically different compared with that in the conventional group. Fluoroscopic time (9.0 vs. 0.008 min) and radiation exposure (29.4 vs. 0.02 mGy) were significantly shorter in the Zero-X group than in the conventional group (P < 0.001). The complication rate did not differ between the two groups. During a mean follow-up of 663.3 ± 172.3 days, the recurrence rate was similar (16.0 vs. 18.0%; P = 0.841) between the groups. Multivariate analysis revealed that LA size was the only independent predictor of clinical recurrence. Intracardiac echocardiography–guided fluoroless CBA for AF was a feasible strategy without compromising acute and long-term success or complication rates.