Impact of the third generation cryoballoon on atrial fibrillation ablation: An useful tool?

BACKGROUND: Third-generation cryoballoon (CB3) is characterized by a 40% shorter distal tip designed to increase the rate of pulmonary veins real-time signal recording in order to measure time necessary to isolate veins, the "Time to effect" (TTE). Few data are currently available on clinical follow up of CB3 treated patients. METHODS: Sixtyeight consecutive patients (mean age 57.8 ±â€¯9.6 years, 48 male) with paroxysmal or persistent atrial fibrillation (AF) were enrolled. Thirthyfour (25 paroxysmal AF) underwent to a 28 mmCB3 pulmonary veins isolation and were compared to 34 treated (21 paroxysmal AF) with 28 mmCB2. RESULTS: CB3 use was correlated to significant increase of the possibility to measure TTE in every treated veins (left superior 82,35% vs 23,53%, left inferior 70,59% vs 38,24%, right superior 58,82% vs 14,71%, right inferior 52,94% vs 17,65%). When it is measured, TTE wasn't different between two groups. Higher nadir temperature was observed in CB3 patients (-39.4 ±â€¯5.2 °C vs -43.0 ±â€¯7.2 °C, p = 0.03). CB3 procedures were shorter (91.4 ±â€¯21.7 vs 110.9 ±â€¯31.8 min, p = 0.018), with a significant reduction in cryoenergy delivery time (24.2 ±â€¯8.5 vs 20.3 ±â€¯6.7 min, p < 0.05), and a significant reduction in left atrium dwell time (59.3 ±â€¯9.8 vs 69.3 ±â€¯10.8 min, p = 0.02, p < 0.05). At one year follow up period the Kaplan-Meier curve didn't show any significant difference in AF-free survival (Log p = 0,49). CONCLUSIONS: Novel CB3 is a useful tool in order to simplify AF cryoballoon ablation when compared to second generation cryoballoon, as observed in our experience. Follow up data seem confirm a clinical CB3 efficacy at least comparable CB2.

The safety and efficacy of third- and fourth-generation cryoballoons for atrial fibrillation: a systematic review and meta-analysis.

Objectives: An increasing number of studies have shown that third (CB3)- and fourth-generation cryoballoons (CB4) have been used to treat various types of atrial fibrillation (AF), but previous research regarding the safety and efficacy of CB3 or CB4 ablation remains controversial. Therefore, a meta-analysis was performed to further evaluate the safety and efficacy of pulmonary vein isolation (PVI) using the CB3 and CB4 in the treatment of AF. Methods: We searched PubMed, the Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wanfang, China Science and Technology Journal Database, and Clinicaltrials.gov up to December 2023 for qualified trials and data extraction according to inclusion and exclusion criteria. All analyses were carried out using Review Manager 5.3 software. Results: The meta-analysis included 13 observational studies consisting of 3,281 subjects and did not include a randomized controlled trial. Overall analyses indicated that the CB3 significantly reduced total procedure time [weighted mean difference (WMD) = -8.69 min, 95% confidence interval (CI) = -15.45 to -1.94 min, I2 = 93%], increased the PVI recording [relative risk (RR) = 1.24, 95% CI = 1.03-1.49, I2 = 90%], and increased the mean nadir temperature of overall PVs (WMD = 2.80°C, 95% CI = 1.08-4.51°C, I2 = 89%) compared with the CB2. Moreover, the CB4 significantly reduced the total procedure time (WMD = -14.50 min, 95% CI = -20.89 to -8.11 min, I2 = 95%), reduced the fluoroscopy time (WMD = -2.37 min, 95% CI = -4.28 to -0.46 min, I2 = 95%), increased the PVI recording (RR = 1.40, 95% CI = 1.15-1.71, I2 = 90%) compared with the CB2. Time-to-isolation, the success rate of PVI, AF recurrence, and complications in the CB3 and CB4 were not significantly different compared with the CB2. Conclusion: These findings demonstrated that the CB3 and CB4 tended to be more effective than the CB2 in the treatment of AF, with shorter procedure times, more PVI recording, and similar safety endpoints.

Impact of pulmonary vein ovality index on cooling kinetics and acute success of atrial fibrillation ablation with the third-generation cryoballoon catheter.

INTRODUCTION: Atrial fibrillation (AF) is the most common arrhythmia, increasing the risk of stroke and all-cause mortality. Pulmonary vein isolation (PVI) with cryoballoon ablation (CBA) is a widely accepted approach for invasive treatment of patients with AF. CBA effectiveness is considered to be strongly dependent upon the anatomy of pulmonary veins, mainly the ovality of pulmonary veins' ostia. However, most published results refer to the second-generation cryoballoon. AIM: To investigate the impact of the ovality index (OI) of pulmonary veins (PVs) on cryokinetic parameters and acute effectiveness of PVI with the third-generation cryoballoon catheter. MATERIAL AND METHODS: We enrolled 54 patients with documented drug-refractory, symptomatic paroxysmal and persistent AF, who underwent CBA with the third-generation cryoballoon between March 2019 and July 2020. Prior to the procedure all patients underwent computed tomography (CT) scans to evaluate anatomy of PVs and calculate the ovality indices for each vein. Analyzed patients were divided into two equal groups depending on the mean OI for all veins. RESULTS: No differences were observed in acute effectiveness, total procedure time, freeze time, need for additional applications and complications in the group with lower (OI < 1.27) and higher (OI > 1.27) OI values. Remarkably, fluoroscopy time was even slightly shorter (p = 0.046) in patients with high OI. CONCLUSIONS: In the analyzed population, increased pulmonary vein OI had no negative effect on the CBA procedure performed with the third-generation cryoballoon catheter; therefore it can be considered as a more comprehensive single-shot PVI tool.