Outcomes Of Cryoballoon Ablation Research Articles

Impact of interatrial septal thickness and interatrial conduction time on cryoballoon ablation outcome

Abstract Introduction Interatrial septal thickness (IAST) is an indirect measure of interatrial septal fat which is anatomic extension of epicardial fat. Interatrial conduction time (IACT) reflects altered conduction between atria. Both parameters are associated with left atrial (LA) fibrosis and atrial fibrillation (AF). However, limited data exist regarding the influence of IAST and IACT on the outcomes of cryoballoon ablation (CBA). In this study, we aimed to analyze possible effect of IAST and IACT on atrial tachyarrhythmia (ATA) free survival after CBA. Methods and results Sixty five patients (34/65, 52.3% male, 53.3±11.0 years old) undergoing first time CBA for pulmonary vein isolation were enrolled. Pre-procedural TEE images were analyzed and bicaval view was used to visualize SVC rim for IAST measurement (Figure 1). IACT was measured from the onset of surface P wave to atrial EGM recorded by distal coronary sinus electrode. After 3 months blanking period all anti-arrhythmic drugs were discontinued. Clinical endpoint was ATA recurrence including AF, flutter or tachycardia lasting more than 30 seconds. After 11.2±4.1 months of follow-up 8 patients (12.3%) had ATA recurrence. IAST (4.4±1.1 vs 3.3±0.6 mm, p=0.007) and LA volume index (37.4±8.0 vs 30.1±12.4 mL/m2, p=0.03) were greater in patients with ATA recurrence than those without. In contrast, patients with and without had similar IACT (85.8±31.1 vs 62.2±23.9 ms, p=0.10). Conclusion Pre-procedural measurement of IAST using TEE may provide prognostic information in CBA patients. Increased IAST was found to be associated with ATA recurrence after CBA based PVI and warrants further study.Interatrial septal thickness measurement

Clinical Outcomes of Intracardiac Echocardiography-Guided Contrast Agent-Free Cryoballoon Ablation in Atrial Fibrillation Patients With Renal Insufficiency.

Previous studies have reported an association between impaired renal function and poor outcomes after radiofrequency catheter ablation in patients with atrial fibrillation (AF). However, outcomes of cryoballoon ablation (CBA) in patients with renal insufficiency are not fully elucidated. This study aimed to compare outcomes of CBA in AF patients with chronic kidney disease (CKD) versus those without CKD and to assess changes in renal function over 12 months following CBA. A total of 839 patients (65.1% with non-paroxysmal AF [PAF]) who underwent de novo CBA were prospectively enrolled. We divided patients into two groups based on creatinine clearance rate (CCr) and performed intracardiac echocardiography (ICE)-guided contrast agent-free CBA. In comparison with patients without CKD (CCr >50, n=722), those with CKD (CCr ≤50, n=117) were older and predominantly female, had a lower body mass index, and showed a higher prevalence of heart failure and hypertension. Mean CHA2DS2-VAS score was significantly higher in CKD group than in non-CKD group. Procedure-related complications were not significantly different between two groups. During a mean follow-up period of 25.4±11.9 months, clinical recurrence occurred in 182 patients (21.7%) and not significantly different between two groups. In multivariate analysis, non-PAF and left atrial size were independent predictors of AF recurrence. CCr levels significantly improved over 12 months after CBA in CKD group. ICE-guided contrast-agent-free CBA showed comparable long-term clinical outcomes without increasing procedure-related complications and improvement of renal function over 12 months following CBA in AF patients with CKD.

Long-term success rates of a stable, low pressure cryo balloon for the treatment of paroxysmal atrial fibrillation - results of the prospective, international, multicenter POLAR-ICE study

Abstract Background/Introduction Pulmonary vein isolation (PVI) using a cryo balloon is well-established for the treatment of paroxysmal atrial fibrillation (PAF). Compared to other available technologies, the usage of a stable, low pressure cryo balloon (POLARx, Boston Scientific) has demonstrated lower nadir temperatures and longer thawing times. However, long term efficacy and safety still needs to be proven. Purpose The aim of the POLAR-ICE Study was to evaluate long-term efficacy and safety outcome of cryo balloon ablation in patients with paroxysmal atrial fibrillation. Methods POLAR ICE, a prospective, non-randomized, international, multicenter study, enrolled 399 patients across 19 centers, between Aug 2020 and May 2021. Patients with paroxysmal atrial fibrillation undergoing de novo PVI were included into the study. During the index procedure, procedural characteristics, such as time to isolation (TTI), cryoablations per pulmonary vein, balloon nadir temperature, and occlusion grade were recorded. Procedural success was defined as successful isolation of each vein proven by entrance block. Follow up visits were at 3, 6, and 12 months. Recurrence is defined as any documented (ECG/Holter) episode of atrial fibrillation / atrial tachycardia longer than 30sec. after a blanking period of 3 months. Results 399 patients (mean age 61 years, 36% female) were included into the study. After 12 months, freedom from any arrhythmia was 83.5% and freedom from atrial fibrillation 88.1% (Figure 1). Procedure/ablation related Serious adverse events occurred in 8.7% of patients, and included access complications (2.6%), cardiac tamponade (0.5%), air embolism (0.3%), AV block (0.3%), effusion (0.3%) phrenic nerve palsy (0.3%), stroke (0.3%), transient ischemic attack (0.3%). Redo procedures have been conducted in 19 patients. In 14/19 pts reconnection of at least one PV could be identified (RSPV n=8, RIPV n=12, LSPV n=9, LIPV n=11). Freedom from any arrhythmia was associated with lower nadir temperature (p=0.008) and longer time to thaw (p=0.05) during the index procedure. Conclusions In this prospective, non-randomized, international, multicenter study, isolation of the pulmonary veins using a stable, low pressure cryo balloon was highly effective and safe in patients treated for paroxysmal atrial fibrillation. Lower nadir temperatures and a longer thawing time were predictors of clinical success.

Cryoballoon ablation for atrial fibrillation in patients with heart failure with mildly reduced and preserved ejection fraction.

Limited data are available on the outcomes of cryoballoon ablation (CBA)-based pulmonary vein isolation (PVI) for atrial fibrillation (AF) in patients with heart failure (HF) with preserved ejection fraction (HFpEF) and mildly reduced ejection fraction (HFmrEF). The present study aimed to evaluate the safety and effectiveness of CBA in such patients. Consecutive patients with AF referred for CBA-based PVI from two highly experienced electrophysiology centres were included in this retrospective study. Of 651 patients undergoing CBA, 471 cases were divided into four groups: No HF (n=255), HFpEF (n=101), HFmrEF (n=78), and HF with reduced ejection fraction (n=37). Similar early recurrence of atrial arrhythmia was found among groups (16.2% vs. 15.4% vs. 14.9% vs. 12.2%, P=0.798), and no significant difference of long-term sinus rhythm (SR) maintenance was identified among the HFmrEF, HFpEF, and No HF groups (71.8% vs. 75.2% vs. 79.6%, P=0.334). CBA is safe for patients with HFmrEF and HFpEF with similar complications compared with the No HF group (3.8% vs. 4.0% vs. 3.1%, P=0.814). The reassessment of cardiac function after CBA showed that patients with HF indicated beneficial outcomes. Left atrial diameter (LAD) and left ventricular ejection fraction were significantly improved in the HFmrEF group. There were 41.6% of patients in the HFpEF group who were completely relieved from HF. LAD and New York Heart Association (NYHA) were associated with recurrence in the HFpEF and HFmrEF groups, and the maintenance of SR was an independent predictor of NYHA improvement for all HF groups. Patients with HFmrEF and HFpEF could benefit from CBA with high SR maintenance and significant HF improvement.

Cryoballoon ablation of atrial fibrillation in octogenarians: one year results from the Cryo Global Registry

Abstract Background A few studies have demonstrated the safety and efficacy of cryoballoon ablation (CBA) in elderly patients (≥75 years old) with atrial fibrillation (AF). However, global utilization and outcomes of CBA in the octogenarian population (≥80 years old) have not been reported. Purpose To evaluate the efficacy and safety of CBA of AF in patients ≥80 years old. Methods The Cryo Global Registry (NCT02752737) is an ongoing, prospective, multicenter registry. In this analysis, 1674 patients with paroxysmal or persistent AF were included in 37 global centers who treated at least one octogenarian with CBA. Analysis cohorts were defined as patients ≥80 and patients <80 years old (control). To address safety issues of CBA in octogenarians, serious procedure-related complications were assessed. Utilizing Kaplan-Meier estimates, 12-month freedom from a ≥30sec AF/atrial flutter (AFL)/atrial tachycardia (AT) recurrence following a 90-day blanking period was evaluated. Results The average age of the octogenarians (n=101) was 82±2 years vs 62±10 years in the control group (n=1573). More females were found in the octogenarian population (51.5% vs 35.7%, p<0.01). The ≥80-year-old cohort had lower BMI (26±4 kg/m2 vs 27±5 kg/m2), higher CHA2DS2-VASc-Scores (4.2±1.3 vs 2.0±1.5), and a higher proportion of heart failure (all p<0.01). The patient cohort ≥80 years was similar compared to the control group regarding the AF history (70.3% vs 74.4% paroxysmal AF), years diagnosed with AF (2.9±4.9 vs 3.2±4.8), and left atrial diameter (43±8 mm vs 42±8 mm) (all p>0.05). Success rates of acute pulmonary vein isolation did not differ between the groups (95.0% vs 96.2%, p=0.59). No differences were observed between ≥80- (5.9%) and <80-year-old patients (3.5%) with respect to serious adverse events (p=0.26). Rhythm monitoring, comprising of Holter and 12-lead ECG, was performed on average 3.1±3.1 times in the elder population and 3.2±3.1 times in the control group through 12 months (p=0.84). Efficacy at 12 months was not different between groups, resulting in 80.6% (95% CI: 71.0–87.3%) freedom from AF/AFL/AT recurrence at 12 months in the octogenarians compared to 78.9% (95% CI: 76.7–80.9%) in the control group (p=0.70). Fewer patients were prescribed AADs at 12 months (32.2%, 23.7%) compared to discharge (47.8%, 49.1%), octogenarians and control, respectively. Further, octogenarians were less likely to receive a repeat ablation 3.3% (95% CI: 1.1–9.7%) in comparison to the control cohort 9.2% (95% CI: 7.8–10.8%) (p=0.052). The 12-month Kaplan-Meier estimate of freedom from cardiovascular-related hospitalization was 81.1% (95% CI: 71.7–87.7%) in the octogenarian and 84.8% (95% CI: 82.9–86.6%) in the control group, respectively (p=0.21). Conclusion Cryoballoon ablation for the treatment of AF is a safe procedure in octogenarians, with efficacy and complication rates comparable to younger patients. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Medtronic, Inc.

Quality of life after first-line cryoablation of atrial fibrillation: results from the Cryo AF Global Registry

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): The registry was sponsored Medtronic, Inc., Minneapolis, MN. Background Atrial fibrillation (AF), the most common cardiac arrhythmia, burdening patients with a myriad of symptoms. Three recent randomized trials demonstrated that cryoballoon ablation (CBA) is superior to antiarrhythmic drugs (AADs) as a first-line treatment for the prevention of arrhythmia reoccurrence in patients with paroxysmal AF. However, the global outcome of CBA performed according to local standard of care as a first-line therapy for AF is not reported. Purpose To compare safety, efficacy, and quality of life outcomes in patients treated with CBA for first-line management of AF against patients treated with CBA following failed AAD therapy. Methods The Cryo AF Global Registry, an ongoing, prospective, multicenter registry, of AF patients undergoing index CBA performed according to local standards at 58 centers in 26 countries worldwide. In this analysis, subjects undergoing first-line cryoablation were compared to patients who were refractory to AAD therapy and/or taking AADs at baseline. Safety was assessed utilizing a composite of serious procedure-related complications. To evaluate efficacy, time-to-first atrial fibrillation, -flutter and/or -tachycardia (AF/AFL/AT) recurrence post a 90-day blanking period was compared between groups using Kaplan-Meier estimates. Quality of life was evaluated using the EQ-5D-3L questionnaire at baseline and at 12 months following CBA. Log-rank, two-sample t-test, and exact binomial tests were utilized to test difference between groups. Results Of 1,394 total patients, 433 (31.1%) were drug naïve prior to CBA. Patients in the AAD therapy cohort failed a mean of 1.2 ± 0.5 AADs before CBA. Freedom from AF/AFL/AT recurrence at 12 months was 87.8% in first-line patients compared to 81.6% in AAD-refractory patients (p<0.01). Serious adverse event rates were not statistically different (p=0.32) between first-line (2.3%) and AAD-refractory (3.4%) patients. First-line CBA resulted in a larger mean decline in symptoms upon follow-up, with 81% of patients reported to be symptom-free at 12 months. Further, first-line patients were prescribed AADs at a lower rate at discharge (18.6% vs.62.8%) and at 12-months (9.7% vs.29.9%) in comparison to patients in the AAD cohort. However, cryoablation did result in AAD prescriptions being reduced by approximately 50% in both cohorts from discharge to 12-months. As determined by the EQ-5D-3L score, quality of life improved for patients in both groups, with no significant difference between first-line and AAD-refractory patients (p=0.29). Conclusion This real-world global evaluation supports CBA as a safe and efficacious first-line treatment that improves the quality of life for patients with symptomatic AF.

Cryoballoon ablation for paroxysmal atrial fibrillation: mid‐term outcome evaluated by ECG monitoring with an implantable loop recorder

The success rate after cryoballoon ablation (CB-A) performed for paroxysmal atrial fibrillation (PAF) might be overestimated by traditional noninvasive monitoring techniques. The purpose of this study was to evaluate the mid-term outcome of CB-A in patients with PAF implanted with an implantable loop recorder (ILR) after the procedure. Between January 2017 and March 2019, all patients who underwent CB-A for PAF and who were subsequently implanted with an ILR were retrospectively included. All devices were equipped with remote monitoring. All ILR-documented atrial tachycardia (AT) or AF episodes ≥ 6 min were considered as recurrence; both true and false episodes were collected. A 3-month post-procedural blanking period (BP) was applied. A total of 102 patients (77 men, mean age 60.6 ± 9.6 years) who underwent pulmonary vein isolation (PVI) by CB-A were included; mean time from first diagnosis of AF to PVI was 51.5 ± 46.9 months. Mean follow-up was 29.3 ± 8.1 months; at 12-month follow-up, the success rate was 65.7%, while at 2-year follow-up, freedom from AT/AF recurrences was achieved in 59.3% of the patients. In the follow-up, a total of 4987 ECG strips were analyzed; true-positive episodes were confirmed in 2026 cases (40.6%), whereas 2961 episodes (59.4%) were considered false-positive. In patients with PAF implanted with an ILR, CB-A results in freedom from any AT/AF recurrence in 65.7% of patients at 12-month follow-up and in 59.3% of patients when evaluated at 2-year. Careful adjudication of all ILR-documented AF episodes is required to avoid misdiagnosis.

Impact of age on the outcome of cryoballoon ablation as the primary approach in the interventional treatment of atrial fibrillation: Insights from a large all-comer study.

The objective was to analyze the impact of patient age on clinical characteristics, procedural results, safety, and outcome of cryoballoon ablation (CBA) as the primary approach in the interventional treatment of symptomatic atrial fibrillation (AF). The single-center prospective observational study investigated consecutive patients who underwent initial left atrial ablation for symptomatic paroxysmal (PAF) or persistent AF (persAF). Age groups (A-F) of less than 40, 40-49, 50-59, 60-69, 70-79 and more than or equal to 80 years were evaluated. Follow-up (FU) included ECG, Holter monitoring and assessment of AF-symptoms. From 2012 to 2016, a total of 786 patients (64 ± 11 years, range 21-85) underwent CBA. With advancing age, more cardiovascular comorbidities and larger LA diameter were observed, more females were included (each p < .001). PAF (57%) and persAF (43%, p = .320) were equally distributed over all age groups. Age was neither related to procedural parameters, nor to the complication rate (3.9%, p = .233). Median FU was 38 months. Two non-procedure related noncardiac deaths occurred late during FU. Freedom from arrhythmia was independent of age at 18 months (p = .210) but decreased for patients more than or equal to 70 years at 24 months (p = .02). At 36 months, freedom from arrhythmia was 66%-74% (groups A-D), 54% (E) and 49% (F), respectively (p = .002). LA diameter and persAF were independent predictors, whereas age was a dependent predictor of recurrence. CBA as the primary approach in the initial ablation procedure is safe and highly effective in the young, middle aged, and elderly population. LA diameter and persAF, but not ageing, were independent predictors for arrhythmia recurrence.

Procedure characteristics and outcomes of atrial fibrillation ablation procedures using cryoballoon versus radiofrequency ablation: A report from the GWTG-AFIB registry.

Cryoballoon ablation (CBA) is an alternative to radiofrequency ablation (RFA) for ablation of atrial fibrillation (AF) and real-world comparisons of this strategy are lacking. As such, we sought to compare patient and periprocedural characteristics and outcomes of CBA versus RFA in the Get With the Guidelines AFIB Registry. Categorical variables were compared via the χ2 test and continuous variables were compared via the Wilcoxon rank-sum test. Adjusted analyses were performed using overlap weighting of propensity scores. A total of 5247 (1465 CBA, 3782 RFA) ablation procedures were reported from 33 sites. Those undergoing CBA more often had paroxysmal AF (60.0% vs. 48.8%) and no prior AF ablation (87.5% vs. 73.8%). CHA2 DS2 -VASc scores were similar. Among de novo ablations, most ablations involved intracardiac echocardiography and electroanatomic mapping, but both were less common with CBA (87.3% vs. 93.9%, p < .0001, and 87.7% vs. 94.6%, p < .0001, respectively). CBA was associated with shorter procedures (129 vs. 179 min, p < .0001), increased fluoroscopy use (19 vs. 11 min, p < .0001), and similar ablation times (27 vs. 35 min, p = .15). Nonpulmonary vein ablation was common with CBA: roof line 38.6%, floor line 20.4%, cavotricuspid isthmus 27.7%. RFA was associated with more total complications compared to CBA (5.4% vs. 2.3%, p < .0001), due to more volume overload and "other" events, although phrenic nerve injury was more common with CBA (0.9% vs 0.1%, p = .0001). In the adjusted model, any complication was less common among CBA cases (odds ratio, 0.45; confidence interval, 0.25-0.79, p = .0056). CBA was associated with fewer complications, and shorter procedure times, and greater fluoroscopy times, compared to RFA. Nonpulmonary vein ablation and electroanatomic mapping system use was common with CBA.

Safety and outcome of cryoballoon ablation versus radiofrequency catheter ablation of the pulmonary veins in patients with paroxysmal atrial fibrillation.

Safety and outcome of cryoballoon ablation versus radiofrequency catheter ablation of the pulmonary veins in patients with paroxysmal atrial fibrillation.

Strategies to Improve the Outcome of Cryoballoon Ablation in the Treatment of Atrial Fibrillation.

Atrial fibrillation (AF) is a common arrhythmia contributing to severe outcomes, including cardiac dysfunction and stroke, and it has drawn great attention around the world. Drug therapies have been available for many years to terminate AF and control heart rate. However, the results from clinical studies on drug therapies have been discouraging. Mounting evidence indicates that radiofrequency catheter ablation (RFCA) is a safe and effective method to maintain sinus rhythm, especially in patients who are drug intolerant or for whom the drugs are ineffective, although it is a technically demanding and complex procedure. Fortunately, a novel application, cryoballoon ablation (CBA), with outstanding characteristics has been widely used. Great outcomes based on CBA have manifested its significant role in the treatment of AF. However, how to improve the safety and efficacy of CBA is a question that has not been well-answered. Would it be helpful to develop a different generation of cryoballoon? Is bonus freezing beneficial, or not? Is it better to prolong freezing time? Dose CBA combined with RFCA bring higher success rates? In this review, we comprehensively summarized useful applications for improving outcomes of CBA in AF patients.

Pulmonary vein isolation and beyond: Predictive value of vagal reactions in second-generation cryoballoon ablation for the outcome of persistent atrial fibrillation

Cryoballoon ablation (CBA) is gaining increasing acceptance in the treatment of persistent (per) atrial fibrillation (AF). The cardiac autonomic nervous system plays a pivotal role in the regulation of AF. We evaluated the impact of vagal reactions (VRs), as a surrogate marker for autonomic nervous system modulation, on the outcome of CBA in patients (pts) with perAF. A total of 250 consecutive pts (mean age 63.9 ± 10.0 years; 175 pts, 70% male) undergoing primary second-generation CBA for perAF were studied. VRs were defined as bradycardia <40 beats/min, asystole, or higher-degree atrioventricular block. Follow-up visits at 3, 6, and 12 months included 7-day Holter electrocardiograms. VRs were recorded in 61 pts (24%). These pts showed a significantly reduced recurrence rate of AF (5%) than did those without VRs (log-rank, P < .01). Univariate Cox regression analyses confirmed VRs as a strong predictor of AF-free survival (hazard ratio [HR] 0.10; P < .01). Female sex (HR 1.71; P = .02), preprocedural tachycardia (HR 1.01; P = .01), and AF (HR 1.75; P = .01) before CBA at admission were revealed as predictors of AF recurrence. Multivariate regression model calculation solely identified VRs (HR 0.11; 95% confidence interval 0.03-0.34; P < .01) and male sex (HR 0.57; 95% confidence interval 0.36-0.89; P = .01) as independent predictors of AF-free survival. VR is an independent predictor of AF-free survival after CBA for perAF.

P1911The impact of pulmonary vein morphology and orientation on the outcomes of cryoballoon ablation in patients with paroxysmal atrial fibrillation

Abstract Background Circumferential contact of cryoballoon and pulmonary vein (PV) ostium is an important factor for pulmonary vein isolation (PVI). PV ostium shape and orientation can make challenges for PV occlusion. Purpose We aimed to assess the impact of pulmonary vein morphology and orientation on cryoablation outcomes in patients with paroxysmal AF. Material and methods The single-center prospective study included 122 patients (males: 46.7% (57), mean age 57 (53; 62) with drug-refractory paroxysmal AF. The mean AF duration was 4 years (2; 4). A multislice cardiac computed tomography (MSCT) was performed prior to CBA in order to evaluate the PV anatomy (maximal and minimal ostium diameters, ovality of PV ostium, angle of PV orientation in the frontal and axial plane (Figure1)). The presence of typical anatomy (4 separate ostia of PVs) was inclusion criteria. Procedures were performed with 28-mm second generation balloon. A procedural endpoint was the achievement of PVI. Outcomes of PVI were defined as freedom from any AF episodes documented by ECG from the end of blanking period to 12 months. Results PVI was achieved in 97.5% of PVs (476/488). Freedom from AF was 78.7%. Difficult occlusion of right inferior PV was observed in 12 patients and associated with a more horizontal PV orientation in the frontal plane: −15.2±6.20 versus −26.5±6.3°, p&lt;0.001. A total of 11 (9%) patients experienced transient phrenic nerve injury (PNI) during ablation of right superior PV (RSPV). PNI was associated with the maximum and minimum diameter of the RSPV 20.0–24.0 mm (OR=13,2; 95% CI: 3.4–51; p&lt;0.05) and 17.5–20.0 mm (OR=12.5; 95% CI: 4.7–41.9; p&lt;0.05), respectively. Patients with AF recurrence had significantly larger maximum and minimum diameters of left superior PV (LSPV): 18.8 versus 17.5 mm, p=0.048, and 13.4 versus 12.5 mm, p=0.05, respectively. Ovality of PV ostium was larger in the recurrence group: 0.36 versus 0.18, p=0.05. Figure 1. Evaluation of PV orientation Conclusions Evaluation of PV morphology and orientation can be used to predict CBA results. AF recurrence was associated with larger diameters and ovality of LSPV ostium. More horizontal RIPV orientation was associated with difficult PV occlusion. RSPV morphology can affect safety of procedure.

Mo1178 OUTCOMES OF ENDOSCOPIC CRYOBALLOON ABLATION FOR TREATMENT OF DYSPLASTIC BARRETT'S ESOPHAGUS

Endoscopic Cryoballoon Ablation (CbA) is a novel technique for treating dysplastic Barrett’s Esophagus using liquid Nitrous Oxide delivered from a diffusion catheter located within a balloon. We aimed to assess the safety and histological outcomes of CbA in BE patients.

Long-term outcome of cryoballoon ablation versus radiofrequency ablation for focal atrial tachycardias originating from the pulmonary veins.

We aimed to investigate the characteristics of focal atrial tachycardias (ATs) arising from the pulmonary veins (PVs), as well as the safety and long-term efficacy of cryoballoon (CB) versus radiofrequency (RF) ablation in this population. Eighty-three patients with ATs arising from PVs from a consecutive series of 487 patients who underwent CB and RF ablation were retrospectively reviewed. Patients who had a prior history of atrial fibrillation (AF) were excluded. The AT origin was confirmed during the conventional electrophysiological study and activation mapping. The ablation approach was at the discretion of the operators. Thirty-five patients were managed with focal ablation, 25 were ablated with unilateral PV isolation (PVI), and the remaining 23 were performed with CB ablation. All procedures were successfully ablated. There was no significant difference in procedure time between CB group and RF focal group (43.7 ± 11.8min vs. 45.8 ± 11.2min, P = 0.121), whereas the fluoroscopy time in CB group was longer than in RF PVI group (10.1 ± 2.5min vs. 8.4 ± 2.8min, P < 0.001). There was 1 recurrence in CB group, 4 recurrences of AT in RF focal group, and 2 recurrence in RF PVI group (P = 0.643). Repeat ablation was performed in 6 of 7 patients. Seventy-eight patients were available for long-term follow-up. At a mean of 5.4 ± 4.6-year follow-up, 77 of 78 patients were free from AT without antiarrhythmic medication after 1.1 ± 0.3 procedures. No patient had procedural complications and developed AF during the follow-up period. CB ablation is an effective and safe tool to treat ATs originating from the PVs. The ATs originating from the PVs represent an isolated clinical process and are not likely to be the forerunner of a more diffuse process leading to the development of PV AF.

Impact of Pulmonary Vein Anatomy on Long-term Outcome of Cryoballoon Ablation for Atrial Fibrillation

Variant pulmonary vein anatomy (PVA) has been reported to influence the recurrence of atrial fibrillation (AF) after radiofrequency ablation. However, the effects of PVA on AF in patients undergoing cryoballoon ablation (CBA) remain unknown. The present study aimed to examine the impact of PVA on the long-term outcome of CBA for AF. A total of 78 patients (mean age 60.7±10.9 years, 64.1% males) with symptomatic and drug-refractory paroxysmal AF were enrolled in the study. Left atrium (LA) and PVA acquired at computed tomography angiography (CTA) were reconstructed with CARTO® 3 SYSTEM. Patients were routinely evaluated by 24-hour Holter monitoring following CBA. Cox regression was used to detect the predictors of AF recurrence after CBA. The results showed abnormal PVA in 30 patients (38.5%) and 18 patients (23.1%) had left common PV (LCPV). Electrical pulmonary vein isolation was achieved in all patients. After a mean follow-up of 689.5±103.8 days, it was found that patients with abnormal PVA had similar AF recurrence rate to those with normal PVA (26.7% vs. 25.0%, P=0.54), and there was no significant difference in AF recurrence rate between LCPV patients and non-LCPV patients (33.7% vs. 23.3%, P=0.29). Cox regression analysis showed that AF duration (72.9±9.0 vs. 42.3±43.2 months, HR 1.001; 95%CI 1.003-1.014; P<0.001) and cryo-applications of right-side PVs (3.0±1.6 vs. 4.7±1.7, HR 0.661; 95% CI 0.473-0.925; P=0.016) were independent predictors of freedom from AF, but PVA was not identified as a predictor of long-term success. In conclusion, the variant PVA cannot significantly influence the long-term outcome of AF patients undergoing CBA; longer AF duration and less cryo-applications of right-side PVs are associated with higher AF recurrent rate.

P825The impact of pulmonary veins anatomy on the outcomes of cryoballoon ablation in patients with atrial fibrillation

P825The impact of pulmonary veins anatomy on the outcomes of cryoballoon ablation in patients with atrial fibrillation

P2671Procedural data, peri-procedural complications and long term outcomes of cryoballoon ablation of paroxysmal atrial fibrillation: the influence of center expertise (high volume vs low volume)

P2671Procedural data, peri-procedural complications and long term outcomes of cryoballoon ablation of paroxysmal atrial fibrillation: the influence of center expertise (high volume vs low volume)

Outcomes of Cryoballoon Ablation in High- and Low-Volume Atrial Fibrillation Ablation Centres: A Russian Pilot Survey.

Purpose. The results of cryoballoon ablation (CBA) procedure have been mainly derived from studies conducted in experienced atrial fibrillation (AF) ablation centres. Here, we report on CBA efficacy and complications resulting from real practice of this procedure at both high- and low-volume centres. Methods. Among 62 Russian centres performing AF ablation, 15 (24%) used CBA technology for pulmonary vein isolation. The centres were asked to provide a detailed description of all CBA procedures performed and complications, if encountered. Results. Thirteen sites completed interviews on all CBAs in their centres (>95% of CBAs in Russia). Six sites were high-volume AF ablation (>100 AF cases/year) centres, and 7 were low-volume AF ablation. There was no statistical difference in arrhythmia-free rates between high- and low-volume centres (64.6 versus 60.8% at 6 months). Major complications developed in 1.5% of patients and were equally distributed between high- and low-volume centres. Minor procedure-related events were encountered in 8% of patients and were more prevalent in high-volume centres. Total event and vascular access site event rates were higher in women than in men. Conclusions. CBA has an acceptable efficacy profile in real practice. In less experienced AF ablation centres, the major complication rate is equal to that in high-volume centres.

Outcome of cryoballoon ablation for atrial fibrillation

We analyzed the medium-term follow-up of cryoballoon ablation (CBA) for atrial fibrillation (AF) and the clinical risk factors predicting outcome. AF patients treated for the first time with CBA in a 4.5-year period were studied retrospectively. Pulmonary vein isolation (PVI) was achieved via a single cryoballoon with diameter of 28mm. Left atrial diameter (LAD) was measured by transthoracic echocardiography. Failure of cryoablation treatment was defined as detection of an episode of AF, atrial flutter, or atrial tachycardia lasting more than 30s during the 3-month follow-up. A total of 212 patients were enrolled and in 87.7 % patients PVI was achieved by CBA. The complication rate was 2.83 %. The mean follow-up was 28 ± 15months; in 166 patients follow-up was complete. The rate of successful treatment for primary CBA was 45.8 %. The percentage of patients who experienced atrial arrhythmia recurrence in the first 12months was 84.44 %. Patients in whom treatment failed had a larger LAD (47 ± 6mm vs. 43 ± 5mm, p < 0.0001). The Kaplan-Meier curve showed that the patients with LAD < 45mm had a higher success rate than patients with LAD ≥ 45mm [57.9 % (44/76) vs. 35.6 % (32/90), log rank = 5.492, p = 0.019]. The LAD [odds ratio, OR = - 0.1053(0.303, 12.2040), p = 0.0005] was shown in logistic regression analysis to be independently predictive of CBA treatment failure. The CBA procedure for AF patients is safe and effective. Most atrial arrhythmia recurrences occurred during the first 12months after CBA. The LAD can independently predict failure of CBA treatment.