Second-generation Cryoballoon Ablation In Patients Research Articles

Safety and Efficacy of Second-Generation Cryoballoon Ablation in Patients Aged over 75 Years

Objective: The use of second-generation cryoballoon (CB2) for pulmonary vein isolation (PVI) in atrial fibrillation (AF) ablation therapy is common. This study aimed to compare the safety and efficacy of CB2 ablation for PVI in AF patients aged 75 years and older to those under 75 years old. Methods: A retrospective, observational study was conducted, including AF patients who underwent CB2 for PVI between January 2018 and December 2020 at our center. The patients were divided into two groups based on age: those aged 75 years and older (elderly group) and those under 75 years (control group). Procedural characteristics, complications, and one-year follow-up outcomes were compared between the two groups using Student's t-test or the chi-square test for univariate analysis. Results: A total of 156 AF patients treated with CB2 for PVI were included in the study, with 78 patients aged 75 years and older (elderly group, mean age = 78 years) and 78 patients aged under 75 years (control group, mean age = 66 years). The PVI procedure duration was 86.2 ± 25.8 minutes for the elderly group and 83.2 ± 20.8 minutes for the control group (p = 0.413). The elderly group showed a higher trend of complications (8/78, 10.3%) compared to the control group (2/78, 2.6%) (p = 0.049), although no serious complications were observed. One-year follow-up revealed that approximately 80% of patients in both groups did not experience AF recurrence (p = 0.656). Conclusion: CB2 ablation for PVI appears to be safe and effective in AF patients aged 75 years and older, with outcomes comparable to those in younger patients. However, special attention should be given to venous puncture in elderly patients.

Medium- and long-term outcome after a single second-generation cryoballoon ablation in patients with paroxysmal and persistent atrial fibrillation

To report medium- and long-term results following a single second-generation cryoballoon (CB2)-based ablation procedure in patients with paroxysmal (PAF) and persistent (PeAF) atrial fibrillation. A retrospective study was performed of consecutive patients undergoing a first CB2-based ablation procedure in a tertiary center. Cryoenergy was applied for 3 min if a time to effect <60 s was documented or 4 min otherwise, with a bonus application in cases of late isolation or suboptimal temperature. Follow-up was obtained from the regional health electronic records system and by telephone or personal interviews. Recurrence was defined as any atrial arrhythmia >30 s beyond a three-month blanking period. The clinical impact of recurrences was classified using a severity score. A total of 172 patients (134 PAF and 38 PeAF) were included, of whom 25 (14.5%) had structural heart disease and 120 (69.7%) had a normal or mildly dilated left atrium. Acute success was achieved in 167 (97.1%). After a median follow-up of 27 (14-41) months, 100 patients (58.1%) remained free of atrial arrhythmias (64.2% for PAF and 36.8% for PeAF, p=0.006). Left atrial size (p=0.05) and clinical presentation as PeAF (p=0.006) were predictors of recurrence. Of patients with recurrences, 11.1% did not require further therapies and an additional 16.7% had good control with antiarrhythmic drugs. A single CB2 procedure resulted in 58.1% of patients remaining free of atrial arrhythmias at 27-month follow-up. Conservative management was useful in 27.8% of patients with recurrences. Relatar os resultados a médio e longo prazo após um único procedimento de crioablação com um sistema de segunda geração (CB2) em doentes com fibrilhação auricular paroxística (PAF) e persistente (pAF). Estudaram-se retrospetivamente doentes consecutivos referidos para uma primeira ablação com CB2 num centro terciário. A ablação foi efetuada com crioenergia aplicada durante 3 minutos se o tempo do efeito foi < 60 s, ou então foi aplicada durante 4 mim, com uma aplicação extra em caso de isolamento tardio ou temperatura subótima. Realizou-se o acompanhamento por meio do registo do sistema de saúde eletrónico regional e pelo telefone ou com entrevistas pessoais. A recorrência foi definida como qualquer arritmia auricular > 30 segundos depois dum período de três meses. O impacto clínico das recorrências foi classificado utilizando uma pontuação de gravidade. Foram estudados 172 doentes (134 PAF e 38 pAF). Vinte cinco (14,5%) tinham doença cardíaca estrutural e 120 (69,7%) tinham uma aurícula esquerda (LA) normal ou levemente dilatada (LA). Foi obtido sucesso agudo em 167 (97,1%). Após um seguimento médio de 27 [14-41] meses, 100 doentes (58,1%) permaneceram livres de arritmias auriculares (64,2% para PAF e 36,8% para pAF, p = 0,006). O tamanho da LA (p = 0,05) e a apresentação clínica de pAF (p = 0,006) foram preditores das recorrências. Dos doentes com recorrências 11,1% não precisaram de terapias adicionais e 16,7% foram bem controlados com medicamentos antiarrítmicos. Dos doentes, 58% ficaram livres de arritmias após um único procedimento CB2, até 27 meses de acompanhamento. Uma estratégia conservadora foi útil nos 27,8% dos doentes com recorrências.

Medium- and long-term outcome after a single second-generation cryoballoon ablation in patients with paroxysmal and persistent atrial fibrillation

Introduction and objectivesTo report medium- and long-term results following a single second-generation cryoballoon (CB2)-based ablation procedure in patients with paroxysmal (PAF) and persistent (PeAF) atrial fibrillation. MethodsA retrospective study was performed of consecutive patients undergoing a first CB2-based ablation procedure in a tertiary center. Cryoenergy was applied for 3 min if a time to effect <60 s was documented or 4 min otherwise, with a bonus application in cases of late isolation or suboptimal temperature. Follow-up was obtained from the regional health electronic records system and by telephone or personal interviews. Recurrence was defined as any atrial arrhythmia >30 s beyond a three-month blanking period. The clinical impact of recurrences was classified using a severity score. ResultsA total of 172 patients (134 PAF and 38 PeAF) were included, of whom 25 (14.5%) had structural heart disease and 120 (69.7%) had a normal or mildly dilated left atrium. Acute success was achieved in 167 (97.1%). After a median follow-up of 27 (14-41) months, 100 patients (58.1%) remained free of atrial arrhythmias (64.2% for PAF and 36.8% for PeAF, p=0.006). Left atrial size (p=0.05) and clinical presentation as PeAF (p=0.006) were predictors of recurrence. Of patients with recurrences, 11.1% did not require further therapies and an additional 16.7% had good control with antiarrhythmic drugs. ConclusionsA single CB2 procedure resulted in 58.1% of patients remaining free of atrial arrhythmias at 27-month follow-up. Conservative management was useful in 27.8% of patients with recurrences.

Procedural findings and clinical outcome of second-generation cryoballoon ablation in patients with variant pulmonary vein anatomy.

The procedural findings and clinical outcome of second-generation cryoballoon (CB2) ablation in patients with variant pulmonary vein (PV) anatomy have not been fully investigated. A total of 424 consecutive patients who underwent PV isolation with CB2 were included. Computed tomographic (CT) scan was performed in all patients before the procedure. The study population was divided into common PV, accessory PV, and nonvariant PV groups according to the CT scan. Procedural findings and clinical outcome between the three groups were compared. Variant PV anatomy was observed in 118 of 424 (27.8%) patients. PV isolation was successfully achieved in all patients in three groups with low rates of need for touch-up ablation (P = 0.974). Total procedure time was longer in the accessory PV group compared with nonvariant PV group (53.7 ± 12.9 vs 49.5 ± 8.8 minutes; P < 0.001). More number of applications per patient were required in accessory PV group compared with the nonvariant PV and common PV groups (7.5 ± 2.1 vs 6.5 ± 1.6, P < 0.001; 7.5 ± 2.1 vs 6.8 ± 1.4, P = 0.027, respectively). No significant difference in phrenic nerve (PN) injury was observed between the three groups (P = 0.693). During mean follow-up duration of 16.1 ± 3.3 months, there was no significant difference in rates of atrial fibrillation (AF) recurrences in the three groups (13 of 43 common PV group, 21 of 75 accessory PV group, and 80 of 306 nonvariant PV group, P = 0.178). Variant PV patterns are common in patients undergoing ablation for drug-resistant AF. CB2 ablation appears to be a reasonable strategy in the setting of the variant PV anatomy with a small increase in procedure time and the number of cryoapplications.

Chromosome 4q25 variants and recurrence after second-generation cryoballoon ablation in patients with paroxysmal atrial fibrillation

BackgroundChromosome 4q25 single-nucleotide polymorphisms (SNPs) are associated with atrial fibrillation (AF) recurrence after radiofrequency catheter ablation, however the underlying mechanism is unknown. Pulmonary vein (PV) reconnections are common post-radiofrequency ablation. We explored the pre-procedural parameters, including AF susceptibility SNPs, predicting the response to PV isolation (PVI) using second-generation cryoballoons. MethodsOne hundred fifty-seven paroxysmal AF patients undergoing PVI using second-generation cryoballoons and genetic testing were enrolled. The top 6 AF-associated Japanese ancestry SNPs were evaluated. Fourteen-day consecutive monitoring was performed to detect AF recurrences. ResultsEarly recurrence of AF (ERAF) was detected in 74(47.1%) patients, and the AF-free survival at 12-months after single procedures was 72.1%. Cox's proportional models determined that higher pro-BNP values (hazard ratio [HR]=1.001; 95% confidence interval [CI]=1.000–1.001; p=0.003) and the rs1906617 risk allele (HR=2.440; 95% CI=1.062–5.605; p=0.035) were independently associated with ERAFs, and the rs1906617 risk allele (HR=4.339; 95% CI=1.044–18.028; p=0.043) was the sole factor significantly associated with AF recurrence. Second procedures were performed in 41 patients a median of 6.0[5.0–9.5] months later, and 42/162(25.9%) PVs were reconnected. Reconnections were similarly observed in rs1906617 risk allele carriers and wild-type patients. Risk allele carriers at rs1906617 were more likely to have non-PV foci, but did not reach statistical significance (10/35 vs. 0/6, p=0.132). ConclusionsAF risk alleles on chromosome 4q25 modulated the risk of AF recurrence after PVI using second-generation cryoballoons in patients with paroxysmal AF. Our study results suggested that non-PV foci might be the more likely mechanism of a high AF recurrence in chromosome 4q25 variant carriers.

Clinical recurrence and electrical pulmonary vein reconnections after second-generation cryoballoon ablation

Electrical reconnections after pulmonary vein isolation (PVI) are less common after second-generation cryoballoon than radiofrequency ablation. The purpose of this study was to investigate the incidence and characteristics of pulmonary vein (PV) reconnections after second-generation cryoballoon ablation in patients with and those without clinical recurrences. Forty patients with paroxysmal atrial fibrillation undergoing second procedures after cryoballoon ablation were enrolled. Twenty-five patients experienced clinical recurrences, and the remaining 15 did not. All 158 PVs were reevaluated a median [25th, 75th percentiles] of 6.0 [4.0-9.0] months after the initial procedure. In total, reconnections were detected in 39 PVs (24.7%) among 25 patients (62.5%). Reconnected PVs included 6 left superior (LS) (15.8%), 7 left inferior (LI) (18.4%), 5 right superior (RS) (12.5%), 20 right inferior (RI) (50.0%), and 1 left common (LC) (50.0%) PV. Reconnected PV potential conduction delays were a median of 112 [76-130], 103 [82-133], 84 [66-96], 68 [49-73], and 204 ms in the LS, LI, RS, RI, and LC PV, respectively. There was no significant difference between those with and those without clinical recurrences with regard to clinical characteristics, procedural results, incidence of reconnections (25/98 vs 14/60, P = .758), and PV conduction delays in each PV. The most common gap location was the RI PV bottom in both groups. Among 5 patients with reconnections of arrhythmogenic PVs (with atrial fibrillation initiation), 2 experienced clinical recurrences, whereas 3 did not. Non-PV foci (with atrial fibrillation initiation) were identified in a second procedures in 10 of 25 patients with clinical recurrences. The incidence and characteristics of PV reconnections after second-generation cryoballoon ablation were similar between patients with and those without clinical recurrences. The results should be considered when discussing the optimal dose of cryoballoon applications.