Underwent Cryoballoon Ablation Research Articles

Impact of shortening the blanking period to 8 weeks after PVI: Insights from COMPARE-CRYO using continuous rhythm monitoring.

Early recurrences of atrial tachyarrythmias (ERAT) after pulmonary vein isolation (PVI) are common. While many correlate to late recurrences (LR), some do not. The impact of ERAT timing is difficult to assess with non-invasive holter monitoring due to undersampling. The recommended duration of the blanking period (BP) was recently shortened from 90 days to 8 weeks. To evaluate the impact of ERAT timing after PVI and the effect of a shorter BP, using implantable cardiac monitors (ICM) for continuous rhythm monitoring. This is a prespecified substudy of the COMPARE-CRYO study, which enrolled patients with paroxysmal atrial fibrillation undergoing cryoballoon ablation. All patients underwent ICM implantation and the BP duration was 90 days. A total of 5285 ERAT episodes occurred in 117/201 patients (58%). Freedom from LR was 82% vs. 37% in patients without vs. with ERAT (p<0.001). When patients were classified according to their last episode of ERAT occurring between days 0-30, 31-60 and 61-90, freedom from LR was 60%, 56% and 11% (p<0.001). Seven of the 201 patients (3.4%) had AF recurrence in the third month after ablation, but not between days 91-365, which reclassifies them from ablation success to ablation failure with the shortened 8-week BP. ERAT after PVI is common. The presence of ERAT in the third month after PVI was highly predictive for ablation failure, supporting the shortening of the BP duration to 8 weeks, however, the shorter BP reclassifies 3.4% of the patients to ablation failure instead of ablation success.

Left atrial appendage volume estimated by artificial intelligence predicts atrial fibrillation recurrence after cryobaloon ablation

Abstract Background/Introduction The volume of the left atrial appendage (LAA), as measured in contrast-enhanced cardiac computed tomography (CCTA), has been previously reported as a predictor of long-term recurrence of atrial fibrillation (AF) following cryoballoon ablation procedures. Unfortunately manual assessment of LAA volume, is tedious and time-consuming, making it impractical for clinical practice. The recent advent of artificial intelligence (AI)-based methods offers a potential solution to this limitation. Purpose This study aims to evaluate the utility of LAA volume, as automatically measured by a state-of-the-art AI model for the fully automatic segmentation of LAA in CCTA, in predicting AF recurrence following cryoballoon ablation procedures. Methods We retrospectively analyzed a cohort of patients who underwent cryoballoon ablation for pulmonary vein isolation at our facility between 2010 and 2016. AF recurrence was determined through in-person visits and Holter monitoring at 3, 6, and 12 months post-ablation, followed by annual visits. The first three months post-ablation were considered a blanking period. An open-source deep neural network AI model [1] was utilized to perform automatic segmentation and calculation of LAA and left atrium (LA) volumes in. Receiver-operating characteristic curves were used to obtain optimal cut-off values for increased LAA and LA volumes. We then assessed the association of increased LAA and LA volume, and the LAA to LA volume ratio with recurrence-free survival using the Cox regression model. Results The cohort consisted of 212 patients (median age 62, inter-quartile range [IQR]: 55–65), with 25% having persistent AF before the procedure. Subjects were observed for a median period of 12 months (IQR: 12–36), with 70 of them (33%) experiencing a documented recurrent AF episode. The optimal thresholds for predicting AF recurrence were established as 9.8ml for LAA volume, 124ml for LA volume, and 0.086 for the LAA to LA volume ratio, respectively. An increased LAA volume demonstrated the strongest association with AF recurrence (hazard ratio [HR]: 2.6, 95% confidence interval [CI]: 1.55–4.2), followed by an increased LA volume (HR: 2.1, 95% CI: 1.3–3.4), persistence of AF (HR: 2, 95% CI: 1.2–3.3), and increased LAA to LA volume ratio (HR: 1.9, 95% CI: 1.1–3). Kaplan-Meier plots illustrating AF-free survival, are presented in Figure 1. After adjusting for age, persistent AF, left ventricular ejection fraction, and body surface area, all AI measurements remained significantly associated with a higher AF recurrence (Table 1). Conclusions Increased LAA volume, as assessed automatically by AI in CCTA, is a useful predictor of AF recurrence after catheter ablation for atrial fibrillation. The use of freely available, AI-assisted analysis of CCTA could be instrumental in assessing LAA volume, among other predictors, for long-term ablation success.Figure 1.

THE INFLUENCE OF PULMONARY VEIN ANATOMY ON OUTCOMES AFTER ABLATION OF PAROXYSMAL ATRIAL FIBRILLATION

Background. Pulmonary vein isolation is the cornerstone of catheter-based treatment for atrial fibrillation. Cryoballoon ablation offers an effective and reproducible method for pulmonary vein isolation, yet recurrence of arrhythmias remains a challenge. Despite advances in catheter technologies, the role of altered pulmonary vein anatomy as a factor for atrial fibrillation recurrence is poorly studied. Materials and Methods. This prospective study included 465 patients with paroxysmal atrial fibrillation who underwent cryoballoon ablation. Pulmonary vein and left atrial anatomy were evaluated using multislice computed tomography. Patients were followed for 24–48 months to assess atrial fibrillation recurrence and anatomical risk factors. Cox proportional hazard modeling and Kaplan-Meier analysis were used to evaluate predictors of arrhythmia recurrence. Results. Complete Pulmonary vein isolation was achieved in all patients. During follow-up, 38% of patients experienced atrial fibrillation recurrence. Patients with altered pulmonary vein anatomy, particularly a left common pulmonary vein and additional pulmonary veins, showed a higher rate of recurrence. Cox regression analysis identified left atrial volume index &gt;50 mL/m² and pathological pulmonary vein anatomy as independent risk factors for atrial fibrillation recurrence. Conclusion. Altered pulmonary vein anatomy is a significant risk factor for atrial fibrillation recurrence following cryoballoon ablation. Comprehensive imaging of the left atrial and pulmonary vein using multislice computed tomography can improve patient selection, reducing the recurrence risk and improving long-term outcomes.

Early Cryoablation After First Diagnosis of Atrial Fibrillation Reduces Arrhythmia Recurrence in Heart Failure Patients

BackgroundAtrial fibrillation (AF) and heart failure (HF) often coexist, leading to increased mortality. A cryoballoon-based approach is a potential treatment for patients with HF because of its safety and efficacy. ObjectivesThe authors sought to evaluate the optimal timing of cryoballoon ablation after the first clinical diagnosis of AF and its prognosis for patients with HF. MethodsThis large-scale multicenter study retrospectively collected data of patients with HF who underwent cryoballoon ablation for AF from 17 Japanese institutions. Patients were divided into 2 groups depending on the duration between the first diagnosis and ablation using a median time of 0.5 year (IQR: 0.3-2.0 years). Clinical endpoints of recurrence, mortality, and HF hospitalization were compared between the 2 groups. ResultsAmong 3,655 patients, 543 with HF were included for analysis. During a median follow-up period of 21.3 months (IQR: 12.0-36.8 months), 151 of 520 patients (29%) had a recurrence. The AF recurrence rate was significantly lower in the early-ablation group (≤0.5 year) than in the delayed-ablation group (>0.5 year) (24% [65/266] vs 34% [86/254], respectively; P = 0.018). In the multivariable analysis, early ablation ≤ 0.5 year was independently associated with an absence of recurrence (HR: 0.581; 95% CI: 0.401-0.842; P = 0.004). Delayed time for cryoballoon ablation incrementally increased the risk of postablation recurrence. Antiarrhythmic drug use was independently associated with delayed ablation. No significant differences in mortality or HF hospitalization were observed between the 2 groups. ConclusionsEarly cryoablation reduced the risk of recurrence in patients with HF, which may help improve clinical management.

Changes in epicardial adipose tissue volume before and after cryoballoon ablation in patients with atrial fibrillation: Supporting the “AF begets EAT” theory

BackgroundEpicardial adipose tissue (EAT) is closely associated with atrial fibrillation (AF), suggesting that it may be one of the causes of AF progression. However, it is unclear whether AF affects EAT. ObjectiveThis study aimed to demonstrate that sinus rhythm restoration reduces EAT volume (EATV) through left atrial reverse remodeling (LARR). MethodsWe analyzed data from 247 patients who underwent cryoballoon ablation for AF. EATV was assessed by contrast-enhanced computed tomography with a 3-dimensional analysis workstation, evaluating EATV surrounding the entire heart (Total-EATV) and left atrium (LA-EATV) at baseline and 6 months after cryoballoon ablation. ResultsAt 6 months, all patients but one with persistent AF were in sinus rhythm. Total-EATV and LA-EATV were both significantly decreased in patients with persistent AF (n = 33; Total-EATV: 148.8 ± 53.3 mL to 142.9 ± 53.5 mL [P = .01]; LA-EATV: 26.8 ± 11.3 mL to 25.2 ± 10.7 mL [P = .01]). No changes were observed in patients with paroxysmal AF (n = 214). Persistent AF was more strongly associated with LARR than paroxysmal AF (odds ratio, 2.34; 95% confidence interval, 1.01–5.44; P = .05). LARR showed an independent correlation with both Total-EATV and LA-EATV reduction (odds ratio, 1.78 [P = .04] and 2.80 [P < .001], respectively). ConclusionThese findings suggest a novel “AF begets EAT” theory, complementing the previously accepted role of EAT as a cause of AF and supporting the “AF begets AF” mechanism.

Effect of early cryoballoon ablation on atrial fibrillation recurrence-A Danish nationwide register study.

Cryoballoon ablation is a safe and efficient rhythm control strategy in atrial fibrillation (AF) patients. The impact of time from diagnosis to ablation is unclear. The aim of this study was to examine the impact of timing of first-time cryoballoon ablation on AF recurrence in a nationwide cohort of AF patients. From nationwide registers, all AF patients ≥18 years of age who underwent first-time AF cryoballoon ablation in Denmark from 2012 to 2018 were included. The AF patients were stratified by ablation timing: Early group (≤1 year after AF diagnosis), intermediate group (1-3 years after AF diagnosis), and late group (≥3 years after AF diagnosis). By adjusted Cox regression models, the effect of timing on AF recurrence was examined. This study included 1064 AF patients with a median age of 63 years. Most patients were male (66%) and had paroxysmal AF (67%). The 1-year risk of AF recurrence increased from 31% in the early group to 41% and 44% in the intermediate and late group. The hazard ratios (95% confidence intervals) were 1.28 (0.95, 1.74) in the intermediate group and 1.42 (1.09, 1.86) in the late group when compared to the early group. Continuous diagnosis-to-ablation time seemed to have the greatest impact on AF recurrence within the first 2 years. In AF patients undergoing cryoballoon ablation, late timing of ablation was associated with a significantly higher AF recurrence rate when compared to early timing of ablation. These findings support early cryoballoon ablation to improve the outcomes after ablation.

Cryoballoon-Assisted Pulmonary Vein Isolation and Left Atrial Roof Ablation Using a Simplified Sedation Strategy without Esophageal Temperature Monitoring: No Notable Thermal Esophageal Lesions and Low Arrhythmia Recurrence Rates after 2 Years.

Atrial fibrillation (AF) ablation is increasingly effective for managing heart rhythm but poses risks like esophageal fistulas. Minimizing esophageal thermal lesions while simplifying procedures is crucial. This prospective study involved 100 consecutive AF patients undergoing cryoballoon ablation with simplified sedation, without esophageal temperature monitoring. Patients with paroxysmal AF (Group A) received pulmonary vein isolation only, while those with persistent AF (Group B) also had left atrial roof ablation. Gastroesophageal endoscopy was performed post-procedure to detect lesions, and cardiological follow-ups were conducted at 3, 12, and 24 months. The cohort included 69% men, with a median age of 65.5 years. Post-ablation endoscopy was performed in 92 patients; esophageal lesions were found in 1.1% of Group A and none of Group B. GERD was diagnosed in 14% of patients, evenly distributed between groups and not linked to lesion occurrence. Gastric hypomotility was observed in 16% of patients, with no significant difference between groups. At 24 months, arrhythmia-free survival was 88% in Group A and 74% in Group B. Cryoballoon-assisted pulmonary vein isolation, with or without additional left atrial roof ablation and without esophageal temperature monitoring during a simplified sedation strategy, shows low risk of esophageal thermal injury and effective ablation outcomes.

Long-term clinical impact of early recurrence of atrial tachyarrhythmia after cryoballoon ablation in patients with atrial fibrillation.

The impact of early recurrence of atrial tachyarrhythmia (ERAT) within the 90-day blanking period on long-term outcomes in atrial fibrillation (AF) patients undergoing cryoballoon ablation (CBA) is controversial. This study aimed to assess the relationship between ERAT and late recurrence of atrial tachyarrhythmia (LRAT) post-CBA. Utilizing data from a multicenter registry in Korea (May 2018 to June 2022), we analyzed the presence and timing of ERAT (<30, 30-60, and 60-90 days) and its association with LRAT risk after CBA. LRAT was defined as any recurrence of AF, atrial flutter, or atrial tachycardia lasting more than 30 s beyond the 90 days. Out of 2636 patients, 745 (28.2%) experienced ERAT post-CBA. Over an average follow-up period of 21.2 ± 10.3 months, LRAT was observed in 874 (33.1%) patients. Patients with ERAT had significantly lower 1-year LRAT freedom compared to those without ERAT (42.6% vs. 85.5%, p < .001). Multivariate analysis identified ERAT as a potential predictor of LRAT, with a hazard ratio (HR) of 3.98 (95% confidence interval [CI], 3.47-4.57). Significant associations were noted across all examined time frames (HR, 3.84; 95% CI, 3.32-4.45 in <30 days, HR, 5.53; 95% CI, 4.13-7.42 in 30-60 days, and HR, 4.29; 95% CI, 3.12-5.89 in 60-90 days). This finding was consistently observed across all types of AF. ERAT during the 90-day blanking period strongly predicts LRAT in AF patients undergoing CBA, indicating a need to reconsider the clinical significance of this period.

Evaluation of microembolic signals on carotid ultrasound during pulmonary vein isolation with high-power short-duration and cryoballoon ablations: When and where do bubble and solid emboli arise?

The underlying risks of asymptomatic embolization during high-power short-duration (HPSD) ablation for atrial fibrillation remain unclear. We aimed to evaluate microembolic signals (MESs) during HPSD ablation with power settings of 50and 90 W in comparison with those during cryoballoon (CB) ablation using a novel carotid ultrasound-Doppler system that classifies solid and air bubble signals using real-time monitoring. Forty-seven patients underwent HPSD ablation using radiofrequency (RF), and 13 underwent CB ablation. MESs were evaluated using a novel pastable soft ultrasound probe equipped with a carotid ultrasound during pulmonary vein isolation. We compared the detailed MESs and their timing between RF and CB ablations. The number of MESs and solid signals were significantly higher in the RF group than in CB group (209 ± 229 vs. 79 ± 32, p = .047, and 83 ± 89 vs. 28 ± 17, p = .032, respectively). In RF ablation, the number of MESs, solid, and bubble signals per ablation point, or per second, was significantly higher at 90 W than at 50 W ablation. The MESs, solid, and bubble signals were detected more frequently in the bottom and anterior walls of the left pulmonary vein (LPV) ablation. In contrast, many MESs were observed before the first CB application and decreased chronologically as the procedure progressed. Signals were more prevalent during the CB interval rather than during the freezing time. Among the 28 patients, 4 exhibited a high-intensity area on postbrain magnetic resonance imaging (MRI). The MRI-positive group showed a trend of larger signal sizes than did the MRI-negative group. The number of MESs was higher in the HPSD RF group than in the CB group, with this risk being more pronounced in the 90 W ablation group. The primary detection site was the anterior wall of the LPV in RF and the first interval in CB ablation.

Arrhythmia-induced versus arrhythmia-superimposed cardiomyopathy: outcome in patients with atrial fibrillation and heart failure undergoing cryoballoon pulmonary vein isolation

Abstract Introduction The outcome in patients with arrhythmia-induced cardiomyopathy (AIC) compared with that in patients with arrhythmia-mediated/superimposed cardiomyopathy (AMC) undergoing cryoballoon pulmonary vein isolation (cryo-PVI) is also poorly defined. Methods In this retrospective observational study, we analysed patients with AF and reduced left ventricular ejection fraction (LVEF &amp;lt; 50%) who underwent cryoballoon ablation between 2014 and 2020. Patients with LVSD were divided into AIC and AMC. AIC was diagnosed ex juvantibus during first year after ablation at 3- and 12-month follow-up when LVEF recovered to &amp;gt; 50% and by more than 10% after ablation and a different aetiology for reduced LVEF was excluded. AMC was diagnosed when structural heart disease was responsible for LVSD and AF had likely exacerbated pre-existing LVSD. For identification of independent predictors of LVEF non-improvement after ablation, univariate and multivariate logistic regression analyses were performed. LVEF non-improvement was defined when LVEF neither increased by more than 10% nor increased over absolute 50% at 12-month follow-up. The first documented &amp;gt; 30-s atrial arrhythmia recurrence after a 3-month blanking period during the one-year follow-up was compared by Kaplan-Meier analysis. Results Out of 1293 consecutive patients who underwent cryoballoon ablation, 113 AF patients with reduced LVEF (&amp;lt;50%) were identified. After 1-year follow-up these patients were divided into AIC (N= 77) and AMC (N = 36) groups. The prevalence of persistent AF was comparable in both groups (85.7% vs. 77.8 %, p = 0.435). LVEF, left atrial (LA) enlargement, and left ventricular end diastolic diameter (LVEDD) were similar between the groups. After one year, the median LVEF improved significantly in the AIC group from 42% (IQR: 35-45%) to 60% (IQR: 58-63%; p &amp;lt; 0.0001) and in the AMC group from 42% (IQR: 33-45%) to 47.5% (IQR= 43-53%; p=0.015). At follow-up LVEF was significantly higher in the AIC than in the AMC cohort (p &amp;lt; 0,001). After univariate and multivariate analysis, the following parameters were associated with non-LVEF improvement: LVEDD (OR = 1.12, p = 0.012) and atrial arrhythmia recurrence (OR = 5.87, p = 0.031; Figure 1). In the AIC group LA area decreased from 25.6 cm2 (IQR: 22.4-29.5 cm2) to 21.8 cm2 (IQR: 18.3-25.2 cm2; p = 0.012). In AMC patients LA enlargement did not change with respect to baseline. Kaplan-Meier curves demonstrated no difference in recurrence-free survival rate between the groups during the 12-month follow-up (75.3% vs. 75%, log-rank P = 0.89; Figure 2). Conclusions LVEDD and arrhythmia recurrence were identified as predictors of non-LVEF improvement after cryo-PVI. The LVEF increased in both groups after ablation, but in AIC group more than in AMC group. In the AIC group LA atrial area decreased compared to the AMC group. Atrial arrhythmia recurrence rates were comparable between AIC and AMC groups after 12 months.Figure 1Figure 2

Outcome after cryoballoon ablation of persistent atrial fibrillation in patients with heart failure with preserved ejection fraction versus tachycardiomyopathy: a propensity score-matched analysis

Abstract Introduction Atrial fibrillation (AF) often coexists with heart failure (HF). The aim of the study was to detect differences in outcome between patients with arrhythmia induced cardiomyopathy (AIC)/tachycardiomyopathy and HFpEF undergoing cryoballoon pulmonary vein isolation (cryo-PVI) using a propensity score-based model. Methods In this retrospective observational study, we analysed persistent AF patients with HFpEF and AIC undergoing cryoballoon ablation between 2014 and 2020. AIC was diagnosed ex juvantibus during the first year after ablation at the 3- and 12-month follow-up when LVEF recovered to &amp;gt; 50% and by more than 10% after ablation and a different aetiology for reduced LVEF was excluded. Propensity score matching was used to pair patients based on their age, sex, CHA2DS2-VASc score and left atrial (LA) area. The primary endpoint was the first documented &amp;gt; 30-s recurrence of atrial arrhythmia after a 3-month blanking period during the one-year follow-up. The secondary endpoints were improvements in NYHA class and reduction of LA area. For identification of independent predictors of atrial arrhythmia recurrence after ablation, univariate and multivariate Cox regression analyses were performed. Results Out of 1293 consecutive patients who underwent cryo-PVI, 148 persistent AF patients with HFpEF and 66 patients with AIC were identified. Propensity score matching yielded 46 patients in each group. HFpEF patients were more symptomatic than AIC patients (NYHA: 2.4 +/- 0.5 vs. 2.0 +/- 0,8; p = 0.002). Other baseline characteristics did not differ between the two groups, except LVEF (57 % [IQR: 52-62%] vs. 41% [QR: 35%-45%]; p= 0.002). Kaplan-Meier curves (Figure 1) demonstrated no difference in recurrence-free survival rate between the groups during the 12-month follow-up (71.7 % vs. 56.5%, log-rank P = 0.16). After the 12-month follow-up, the median LA area decreased significantly in the HFpEF group from 25.8 cm2 (IQR: 23.4-29.5 cm2) to 24.6cm2 (IQR: 22.0-29.6 cm2; p = 0.045) and in the AIC group from 26.6 cm2 (IQR: 22.9-31.1 cm2) to 23.0 cm2 (IQR: 18.3-25.2 cm2; p=0.024). At the 12-month follow-up the median LA-area was significantly higher in the HFpEF than in the AIC cohort (p= 0.007). NYHA class improved significantly in both groups from baseline. At the 1-year follow-up NYHA class was similar between both groups (1.6 +/- 0.8 vs. 1.4 +/- 0,6; p = 0.206). After univariate and multivariate analysis, the following predictors of atrial arrhythmia recurrence were identified: body-mass-index (BMI; HR = 1.082, p = 0.015) and LA area (HR = 1.079, p = 0.003). Conclusions Cryoballoon catheter ablation of persistent AF seems to have similar effectiveness on arrhythmia free survival in patients with HFpEF and AIC. NYHA class and LA enlargement improved after ablation in both groups although LA area in HFpEF was higher than in AIC patients at follow-up. BMI and LA area were identified as predictors of arrhythmia recurrence.

Pseudo-vagal Responses Elicited by Cryoballoon Ablation.

Pulmonary vein isolation via cryoballoon (CB) ablation is the cornerstone ablation strategy for the treatment of atrial fibrillation (AF). Acute intraprocedural hypotensive and/or bradycardic responses have been reported in patients undergoing CB ablation for AF. However, it remains unclear as to whether these are due to a true vagal response (VR), which can be used to predict long-term outcomes of CB ablation. We analyzed 139 freezes across 17 patients who received CB ablation for paroxysmal AF, measuring vital signs and freeze characteristics. Only one freeze was associated with both hypotension and bradycardia, constituting a true VR. Several freezes were associated with hypotension only that did not respond to atropine administration, suggesting that these responses are not associated with a VR. Hypotensive responses were significantly associated with ice bubble bursts during CB deflation. Unlike the true VR reported in patients undergoing conscious sedation, the presence of acute hypotension shortly after CB deflation cannot be used as a predictor for long-term ablation outcomes.

Efficacy and safety of pulmonary vein isolation with pulsed field ablation vs. novel cryoballoon ablation system for atrial fibrillation.

Pulsed-field ablation (PFA) has emerged as a novel treatment technology for patients with atrial fibrillation (AF). Cryoballoon (CB) is the most frequently used single shot technology. A direct comparison to a novel CB system is lacking. We aimed to compare pulmonary vein isolation (PVI) using PFA vs. a novel CB system regarding efficiency, safety, myocardial injury, and outcomes. One hundred and eighty-one consecutive patients underwent PVI and were included (age 64 ± 9.7 years, ejection fraction 0.58 ± 0.09, left atrial size 40 ± 6.4 mm, paroxysmal AF 64%). 106 patients (59%) underwent PFA (FARAPULSE, Boston Scientific) and 75 patients (41%) underwent CB ablation (PolarX, Boston Scientific). The median procedure time, left atrial dwell time and fluoroscopic time were similar between the PFA and the CB group with 55 [interquartile range (IQR) 43-64] min vs. 58 (IQR 48-69) min (P < 0.087), 38 (30-49) min vs. 37 (31-48) min, (P = 0.871), and 11 (IQR 9.3-14) min vs. 11 (IQR 8.7-16) min, (P < 0.81), respectively. Three procedural complications were observed in the PFA group (two tamponades, one temporary ST elevation) and three complications in the CB group (3× reversible phrenic nerve palsies). During the median follow-up of 404 days (IQR 208-560), AF recurrence was similar in the PFA group and the CB group with 24 vs. 30%, P = 0.406. Procedural characteristics were very similar between PFA and CB in regard to procedure duration fluoroscopy time and complications. Atrial fibrillation free survival did not differ between the PFA and CB groups.

Ratio of P-Wave Duration to P-Wave Amplitude and Left Atrial Remodeling: Insights from Electrophysiological Findings and Myocardial Injury After Cryoballoon Ablation

The impact of the P-wave morphology on clinical outcomes post-catheter ablation (CA) and recurrent arrhythmia characteristics or electrophysiological findings in paroxysmal atrial fibrillation (PAF) patients remains unclear. PAF patients who underwent cryoballoon ablation were enrolled. In twelve-lead electrocardiography recorded within one-month before CA, the P-wave duration (Pd) and P-wave vector magnitude (Pvm) (square root of the sum of the squared P-wave amplitude in leads II, V6 and one-half of the P-wave amplitude in V2) were measured and divided into two groups; patients with high and low Pd/Pvm based on a statistically calculated cut-off value. We evaluated the incidence of late recurrence of AF (LRAF), myocardial injury (high-sensitive troponin I [hs-TnI]) and the electrophysiological findings in repeat ablation sessions. This study included 269 PAF patients. The median follow-up duration was 697 days. The cut-off value of the Pd/Pvm for predicting LRAF was 740.7ms/mV (AUC=0.81, sensitivity=58.2% and specificity=89.6%). Multivariable Cox proportional hazards analysis showed high Pd/Pvm (>740.7ms/mV) was significantly associated with LRAF (p<0.001). The hs-TnI level was significantly lower and ratio of DR-FLASH score>3 significantly higher in those with high than low Pd/Pvm (p=0.044, p=0.002, respectively). In the repeat ablation sessions, the Pd/Pvm in patients with atrial tachycardia (AT) induced or spontaneously occurring during the repeat CA sessions was significantly higher than in those without (p=0.009). There was a significant difference between the Pd/Pvm and low-voltage area (LVA) (p<0.001). In conclusion, the Pd/Pvm is significantly associated with LRAF after cryoballoon ablation in PAF patients and predicts left atrial LVAs and AT inducibility.

Occlusion and catheter ablation using a large-size cryoballoon for various pulmonary veins: a case series

Abstract Background It is established that pulmonary vein isolation using the POLARx™ (Boston Scientific, Marlborough, MA, USA) cryoballoon is a rapid, safe, and effective approach. The new POLARx™ FIT (Boston Scientific), which is expandable from 28 to 31 mm in diameter, is currently available. However, there is limited evidence available regarding the treatment of atrial fibrillation in this setting. In this article, we report a case series of cryoballoon ablation in patients with atrial fibrillation using POLARx™ FIT. Case summary This case series describes a comparison of obstruction in three patients with pulmonary veins of different shapes and diameters undergoing cryoballoon ablation and pulmonary vein isolation with a 31 mm diameter balloon. Discussion Cryoballoon ablation using the 31 mm mode of POLARx™ FIT has the potential to provide safe and stable pulmonary vein isolation with good occlusion for a variety of pulmonary vein geometries. In this case series, the 31 mm mode of the POLARx™ FIT resulted in better pulmonary vein occlusion than the 28 mm mode in patients with large left atria and large pulmonary veins, including the left common pulmonary vein. This approach may be considered a first-line therapy option of cryoballoon ablation in patients with atrial fibrillation.

Efficacy of nonocclusive separate freezing technique of cryoballoon pulmonary vein isolation: comparison of novel and conventional cryoballoon system

Abstract Background/Introduction Complete occlusion of pulmonary vein (PV) with cryoballoon is an important factor to achieve enough temperature drop and successful pulmonary vein isolation (PVI). However, it is sometimes difficult to occlude PV completely because of large diameter or anatomical difference. Distal cryoblloon positioning in the PV can achieve complete occlusion but it may increase risk of phrenic nerve injury or PV stenosis. Nonocclusive separate freezing technique, freezing superior and inferior portion of the PV at proximal side with no complete occlusion, may be useful for that situation but efficacy of the technique is not well elucidated. Purpose The purpose of this study is to investigate efficacy of nonocclusive separate freezing technique and compare procedure details of the POLARx and the Arctic Front Advance Pro (AFA-Pro). Methods We retrospectively analyzed consecutive patients who underwent cryoballoon ablation with nonocclusive separate freezing technique from September 2019 to February 2023. We defined failure of the nonocclusive separate freezing as the case which needed distal complete occlusion with cryoballoon or touch up radiofrequency ablation to achieve PVI. We analyzed success rate of nonocclusive separate freezing and evaluated nadir temperature, freezing time and number of application times. We also explored incidence of stop of freezing due to phrenic nerve injury (PNI) or esophageal temperature drop during the procedure and permanent PNI and gastroesophageal complications after the procedure between the POLARx and the AFA-Pro. Results One-hundred and one patients, 73 were male (72.3%) and mean age was 66.8 ± 10.5 years, were analyzed. Total PVs were 121 (left superior (LS) PV 31, right superior (RS) PV 53, left common (LC) PV 37) and the POLARx was 45 (LSPV 18, RSPV 24, LCPV 3) and the AFA-Pro was 76 (LSPV 13, RSPV 29, LCPV 34). Success rates of the separate freezing of the POLARx was 84.4% and the AFA-Pro was 77.6% (p=0.48). There were no significant differences in freezing time and number of application times but nadir temperature was significantly lower in the POLARx (-52.1 ± 4.7 °C vs -42.9 ± 7.2 °C, p&amp;lt;0.001). The incidence of stop of freezing had no significant difference between the POLARx and the AFA-Pro but nadir temperature of stop of freezing due to esophageal temperature drop was significantly lower in the POLARx (-53.8 ± 4.3 °C vs -44.7 ± 7.7 °C, p=0.039). Permanent PNI was not seen but two gastric hypomotility events occurred in the POLARx. Conclusions There was no significant difference of success rate of the nonocclusive separate freezing technique but it tended to be higher and nadir temperature was significantly lower in the POLARx. There was no obvious complication in the AFA-Pro but two gastric hypomotility events were seen in the POLARx.

New mapping for determination of left atrial posterior wall isolation for non-paroxysmal atrial fibrillation

Abstract Background Recent studies have reported that the efficacy of posterior wall isolation(PWI) created by cryoballoon for non-paroxysmal atrial fibrillation. However, there are no clear criteria for determining whether or not to perform PWI, and it is left to the discretion of the operator. Then we evaluated the necessity of additional PWI by measuring non-passively activated ratios(%NP), the ratio of the form of rotors and multiple wavelets, using ExTRa mapping and verified its usefulness. Methods and Results 44 patients with non-paroxysmal atrial fibrillation who underwent cryoballoon ablation(CBA) were divided into two groups according to whether using ExTRa mapping(ExTRa group; 21 patients) or not(no-ExTRa group; 23 patients), and the long-term results were compared. In ExTRa group, ExTRa mapping was performed before PVI, after PVI, and after roof block(LA-RB) creation using cryoballoon. After creating LA-RB, if more than 50% of %NP remained in the left atrium, PWI was performed by creating a bottom block(LA-BB) using cryoballoon. After a median follow-up period of 12months(2 to 34 months), arrhythmia-free survival rate was higher in the ExTRa group than in the no-ExTRa group(95.2% vs 69.6%, p&amp;lt;0.05%). Conclusion Evaluation of %NP using ExTRa mapping is extremely useful in determining the additional PWI for non-paroxysmal atrial fibrillation.Voltage mapping &amp; ExTRa mapping

Development and validation of a novel nomogram for predicting recurrent atrial fibrillation after cryoballoon ablation.

Few studies have explored the use of machine learning models to predict the recurrence of atrial fibrillation (AF) in patients who have undergone cryoballoon ablation (CBA). We aimed to explore the risk factors for the recurrence of AF after CBA in order to construct a nomogram that could predict this risk. Data of 498 patients who had undergone CBA at Ruijin Hospital, Shanghai Jiaotong University School of Medicine, were retrospectively collected. Factors such as clinical characteristics and biophysical parameters during the CBA procedure were collected for the selection of variables. Scores for all the biophysical factors-such as time to pulmonary vein isolation (TTI) and balloon temperature-were calculated to enable construction of the model, which was then calibrated and compared with the risk scores. A 36-month follow-up showed that 177 (35.5%) of the 489 patients experienced AF recurrence. The left atrial volume, TTI, nadir cryoballoon temperature, and number of unsuccessful freezes were related to the recurrence of AF (P < .05). The area under the curve (AUC) of the nomogram's time-dependent receiver operating characteristic curve was 77.6%, 71.6%, and 71.0%, respectively, for the 1-, 2-, and 3-year prediction of recurrence in the training cohort and 77.4%, 74.7%, and 68.7%, respectively, for the same characteristics in the validation cohort. Calibration and data on the nomogram's clinical effectiveness showed it to be accurate for the prediction of recurrence in both the training and validation cohorts as compared with established risk scores. Biophysical parameters such as TTI and cryoballoon temperature have a great impact on AF recurrence. The predictive accuracy for recurrence of our nomogram was superior to that of conventional risk scores.

Adjunct posterior wall isolation reduces the recurrence of atrial fibrillation in patients undergoing cryoballoon ablation: A systematic review and meta-analysis.

Recurrence rates of atrial fibrillation (AF) remain high even after complete wide area circumferential pulmonary vein isolation (PVI). In recent years adjunct posterior wall isolation (PWI) has been performed in patients with more persistent forms of AF but the benefits remain unclear. The objective of this meta-analysis was to evaluate the efficacy of adjunct posterior wall isolation in reducing recurrence rates of AF using cryoballoon ablation (CBA). We searched PubMed, Google Scholar, Clinicaltrials.gov and Cochrane CENTRAL. We included studies comparing PVI to PVI + PWI in patients with either persistent or paroxysmal AF (PAF) undergoing CBA. After data extraction and quality assessment of the studies, we assessed recurrence rates of atrial tachy-arrhythmias (AF, atrial flutter, and atrial tachycardia) as well as total ablation time and procedural adverse events. Risk ratio (RR), mean difference (MD), and 95% confidence interval (CI) were calculated using Review Manager. Concomitant PWI exhibited a substantial reduction in the risk of AF recurrence (RR: 0.51; 95% CI: 0.42-0.63, p < .00001), as well as all atrial arrhythmias (RR: 0.58; 95% CI: 0.49-0.68, p < .00001). On subgroup analysis, in patients with only PAF, adjunct PWI resulted in significant reduction in recurrence risk of AF (RR: 0.56; 95% CI: 0.41-0.76, p = .0002) as well. There was no significant difference in adverse events between both groups (RR: 0.90; 95% CI: 0.44-1.86; p = .78), whereas total ablation time was significantly increased in PVI + PWI group (MD: 21.75; 95% CI: 11.13-32.37, p < .0001). Adjunct PWI when compared to PVI alone decreases recurrence rates of atrial fibrillation after CBA of patients with persistent as well as paroxysmal atrial fibrillation.

CE-452778-4 SKIPPING ABLATION LESIONS DOES NOT AFFECT ATRIAL ARRHYTHMIA RECURRENCE AFTER PULMONARY VEIN ISOLATION IN PERSISTENT AF: A DECAAF II SUBSTUDY

Skip lesions are often performed during ablation for atrial fibrillation (AF) either because of difficulty in catheter positioning or commonly to minimize thermal stacking. There is no clear consensus whether skipping lesions during Pulmonary Vein Isolation (PVI) affects atrial arrhythmia (AA) recurrence after the procedure. We sought to study the effect of skip lesions on AA recurrence in pts undergoing a first time PVI only procedure for persistent atrial fibrillation (PrAF). The DECAAF II Trial was a prospective randomized controlled trial of pts with PrAF undergoing first time ablation. Of 408 pts in the control group (PVI alone), 189 were excluded due to having missing ablation lesions data or having underwent Cryoballoon ablation. The remaining 219 pts constitute the study population. From those pts, 22,377 ablation lesions with their respective space (x, y, z) and time coordinates were collected (figure). Two time-consecutive lesions were considered skip lesions if the Euclidian distance between them was >10 millimeters. Pts were instructed to provide single-lead home ECG strips once daily and during symptoms. A survival analysis using log-rank was performed to assess for atrial arrhythmia through 365 days following a 90-day blanking period. At baseline, the mean pt age was 62 yrs, and 78% were male. There were 15,805 non-skip lesions and 6,572 skip lesions. The median skip lesions percentage per pt was 40%. Skip lesions had increased impedance drop (10.94±16 vs 9.19±13, p<0.001), and force-time interval (266±297 vs 224±219, p<0.001), compared to non-skip lesions. There was similar ablation index reached between skip and non-skip lesions (392.7±97 vs 395.6±110, p=0.62). The percentage of skip lesions was not predictive of AA recurrence when studied as a continuous variable or when modeled using different cutoff threshold values (p=0.45). Similarly, no differences were seen in the percentage of skip lesions in pts with AA recurrence and those without (35 vs 36%, p=0.99). Also, no difference was seen in procedural time and follow-up ablation scar in pts with >40% skip lesions vs <40%. The use of skip lesions was very common in the present point-by-point ablation era. The use of skipped lesions was not related to worsened long-term outcomes after PVI in pts with PrAF.