Cryoballoon Pulmonary Vein Isolation Research Articles

Microembolizations in the arterial cerebral circulation during atrial fibrillation ablation: cryoballoon technique advantages and neurocognitive safety-results of a prospective observational study.

The significance of micro-embolic signals (MESs) during atrial fibrillation (AF) ablation is unclear. Previous studies had limitations, and cryoballoon (CB) ablation patients were under-represented. Minimizing MESs is recommended due to their uncertain neurocognitive impact. This prospective observational study included AF patients from a German centre between February 2021 and August 2022. Patients were equally divided into paroxysmal (Group A) and persistent (Group B) AF. Group A received cryoballoon-pulmonary vein isolation only, while Group B also had left atrial roof ablation. MESs were detected using transcranial Doppler ultrasonography during ablation. Neurocognitive status was assessed pre- and post-procedure and at 3 months using the CERAD Plus battery. The study analyzed 100 patients with a median age of 65.5 years. A total of 19 698 MESs were observed, with 80% being gaseous and 20% solid in origin, primarily occurring during pulmonary vein angiography and the balloon freeze and thawing phase. The median MES per patient was 130 (IQR: 92-256) in total, 298 (IQR: 177-413) in bilateral (36%), and 110 (IQR: 71-130) in unilateral (64%) recordings. No significant difference in total MES counts was found between the groups. None of the 11 neuropsychological tests showed cognitive decline post-procedure or at 3 months. Our observations confirm that neurocognitive abilities are not affected either 24 h or 3 months after AF ablation using the CB technique. However, despite the low MES burden associated with the CB, more work is needed to reduce small embolic events during AF ablation.

A danish healthcare-focused economic evaluation of first-line cryoballoon ablation versus antiarrhythmic drug therapy for the treatment of paroxysmal atrial fibrillation

IntroductionThree randomised controlled trials (RCTs) have demonstrated that first-line cryoballoon pulmonary vein isolation decreases atrial tachycardia in patients with symptomatic paroxysmal atrial fibrillation (PAF) compared with antiarrhythmic drugs (AADs). The aim of this study was to develop a cost-effectiveness model (CEM) for first-line cryoablation compared with first-line AADs for the treatment of PAF. The model used a Danish healthcare perspective.MethodsIndividual patient-level data from the Cryo-FIRST, STOP AF and EARLY-AF RCTs were used to parameterise the CEM. The model structure consisted of a hybrid decision tree (one-year time horizon) and a Markov model (40-year time horizon, with a three-month cycle length). Health-related quality of life was expressed in quality-adjusted life years (QALYs). Costs and benefits were discounted at 3% per year. Model outcomes were produced using probabilistic sensitivity analysis.ResultsFirst-line cryoablation is dominant, meaning it results in lower costs (-€2,663) and more QALYs (0.18) when compared to first-line AADs. First-line cryoablation also has a 99.96% probability of being cost-effective, at a cost-effectiveness threshold of €23,200 per QALY gained. Regardless of initial treatment, patients were expected to receive ∼ 1.2 ablation procedures over a lifetime horizon.ConclusionFirst-line cryoablation is both more effective and less costly (i.e. dominant), when compared with AADs for patients with symptomatic PAF in a Danish healthcare system.

Pulmonary Vein Isolation or Pace and Ablate in Elderly Patients With Persistent Atrial Fibrillation (ABLATE Versus PACE)—Rationale, Methods, and Design

Age is a major risk-factor for atrial fibrillation (AF) and associated hospitalisations. With increasing emphasis on rhythm control, pulmonary vein isolation (PVI) is often suggested, even to elderly patients (≥ 75 years of age). Efficacy of PVI aiming at rhythm control is limited in persistent AF. Pacemaker implantation with atrioventricular node (AVN) ablation may represent a reasonable alternative, with the aim of controlling symptoms and improving quality of life in elderly patients. In this investigator-initiated, randomised, multicentre trial, we test the hypothesis that pacemaker implantation and AVN ablation provides superior symptom control over PVI in elderly patients with symptomatic persistent AF, without any increase in adverse event profile. In the ABLATE Versus PACE (NCT 04906668) prospective open-label superiority trial, 196 elderly patients with normal ejection fraction and symptomatic persistent AF despite guideline-indicated medical therapy will be randomised to either cryoballoon PVI (ABLATE) or dual-chamber pacemaker implantation with subsequent AVN ablation (PACE), and followed for a minimum of 12 months. The primary efficacy outcome is a composite end point of rehospitalisation for atrial arrhythmia or cardiac decompensation/heart failure, (outpatient) electrical cardioversion, or upgrade to cardiac resynchronisation therapy owing to worsening of left ventricular ejection fraction to ≤ 35%. Secondary end points include death from any cause, stroke, quality of life, and procedure-related complications. Sample size is designed to achieve 80% power for the primary end point (2-tailed alpha of 5%). ABLATE Versus PACE will determine whether pacemaker implantation and AVN ablation can improve symptom-control in elderly patients with persistent AF over PVI without increasing safety end points.

Real-world evidence demonstrates an appropriate atrial fibrillation population for hybrid convergent approach versus stand-alone cryoballoon ablation: A long-term safety and efficacy study.

A hybrid convergent approach (endocardial and epicardial ablation) demonstrated superior effectiveness in a recent randomized study for long-standing persistent atrial fibrillation (LSPAF). Yet, there is a lack of real-world, long-term evidence as to which patients are best candidates for a hybrid convergent approach compared to standard endocardial cryoballoon pulmonary vein isolation (CB PVI). This single-center, retrospective analysis spanning from 2010 to 2015 compared two distinctly different atrial fibrillation (AF) cohorts; one treated with stand-alone cryoablation and one treated with a hybrid convergent approach. Baseline characteristics described candidates for each approach. The following criteria were utilized to determine CB PVI candidacy: (1) paroxysmal AF (PAF) (stage 3A) with failed class I/III antiarrhythmic drug (AAD) or (2) persistent/LSPAF (stage 3B/3C/3D) with failed class I/III AAD unwilling to undergo hybrid procedure. Selection criteria for the hybrid procedure included: (1) PAF refractory to both class I/III AAD and prior CB PVI (stage 3D) or (2) persistent/LSPAF (stage 3B/3C/3D) with failed class I/III AAD agreeable to hybrid procedure. Prior sternotomy was excluded. Serial electrocardiograms and continuous monitoring evaluated primary efficacy outcome of time-to-first recurrence of atrial arrhythmia after a 90-day blanking period. Secondary outcomes were procedure-related complications and AAD use (at discharge, 12, and 36 months). Kaplan-Meier methods evaluated arrhythmia recurrence. Of 276 patients, 197 (64.2 ± 10.6 years old; 66.5% male; 74.1% 3A-PAF; 18.3% 3B/3D-persistent AF; 1.0% 3C-LSPAF; 6.6% undetermined) underwent CB PVI and 79 (61.4 ± 8.1 years old; 83.5% male; 41.8% 3D-PAF; 45.5% 3B/3D-persistent AF; 12.7% 3C/3D-LSPAF) underwent hybrid procedure. Arrhythmia freedom through 36 months was 55.2% for CB PVI and 50.4% for hybrid (p = .32). Class I AAD utilization at discharge occurred in 38 (19.3%) patients in the CB PVI group and 5 (6.3%) patients in the hybrid group (p = .01). CB PVI class I AAD utilization at 12 months occurred in 14 (9.0) patients versus 0 patients for hybrid convergent (p = .004). Patients with one or more adverse event were as follows: two (1.0%) in the CB PVI group (both transient phrenic nerve palsy) and three (3.7%) in the hybrid group (two with significant bleeding and one with wound infection) (p = .14). This study demonstrated that patients with more complex forms of AF (3D-PAF or 3B/3C/3D-persistent/LSPAF) could be well managed with a convergent approach. In a real-world evaluation, outcomes match safety and efficacy thresholds achieved for patients with earlier, less complex AF etiologies treated by CB PVI alone.

Pulmonary Vein Isolation with Pulsed Field Ablation and Size-Adjustable Cryo-Balloon: A Comparative Procedural Analysis of First-Time Use.

Background: Pulmonary vein isolation (PVI) is the standard of care for the treatment of symptomatic atrial fibrillation (AF). Novel techniques for PVI are the thermal size-adjustable cryo-balloon (CB) system and non-thermal pulsed field ablation (PFA) system. There are currently no data available for a direct comparison between these two systems. Furthermore, with new techniques, it is important to ensure a high level of efficiency and safety during treatment right from initial use. Therefore, the aim of this study was to directly compare the procedural data and safety of these two new PVI techniques in first-time users. Methods: We conducted a single-center prospective study involving 100 consecutive patients with symptomatic atrial fibrillation who underwent first-time PVI using either size-adjustable CB PVI or PFA PVI from July 2023 to March 2024. Results: Acute PVI was achieved in 100% of patients in both groups. First-pass isolation (FPI) was more frequently achieved in the PFA group compared to the size-adjustable CB group. The mean procedural duration and fluoroscopy dose were significantly shorter in the PFA cohort (p < 0.001). Furthermore, a significant reduction in fluoroscopy time was observed during the learning curve within the PFA group (p = 0.023). There were no major complications in both groups. Conclusions: Both systems demonstrate good effectiveness and safety during PVI performed by first-time users. However, the PFA group exhibited a significantly shorter procedural duration.

Impact of obesity and pattern of atrial fibrillation on long-term outcome following cryoballoon pulmonary vein isolation

Abstract Background Cryoballoon (CB) pulmonary vein isolation (PVI) is an accepted method for treatment of paroxysmal and persistent atrial fibrillation (PAF, PeAF). Obese and PeAF patients do worse following ablation. However, there are limited data on the impact of both variables on outcomes. Objective To understand the impact of obesity and AF pattern on long-term outcomes following CB PVI. Methods We enrolled consecutive AF patients undergoing CB PVI; all patients had an implantable loop recorder (ILR) for long term continuous monitoring. Obesity (O) was defined as a BMI ≥ 30 kg/m2. The cohort was divided into 4 groups based on presence of obesity and type of AF at the initial ablation: (1) N-O (non-obese) and PAF, (2) O and PAF, (3) N-O and PeAF, and (4) O and PeAF. We assessed long-term AF recurrences, after excluding an initial 3-month post-ablation blanking period. Results The cohort included 322 patients (67 ± 9 years; 209 [65%] male; 177 [55%] PAF; CHA2DS2-VASc 2.7 ± 1.6, 137 [43%] O). Obese patients were younger and more likely to have hypertension and diabetes. During a follow-up of 931 ± 599 days, 211 (66%) patients had recurrent AF. The best outcome was seen in N-O obese patients with PAF; all other groups fared similarly (Figure). Group 1 had significantly lower AF recurrence compared to all 3 other groups (Figure). In multivariate analysis, obesity/AF type was the only significant predictor of AF recurrence (Table). As compared to N-O PAF pts, O PeAF patients had a 2-fold greater likelihood of AF recurrence. Conclusions During almost 3-years of objective follow-up, we found that CB PVI performs best in non-obese pts with PAF. Once obesity occurs, PAF pts respond as poorly to PVI as pts with PeAF, irrespective of obesity status. Additional strategies are needed in these patients.

Standalone transcatheter left atrial appendage closure or combined with cryoballoon pulmonary vein isolation

Abstract Background Head-to-head comparisons between stand-alone left atrial appendage closure (LAAC) and a same-procedure LACC + cryoballoon (CB) pulmonary vein isolation (PVI) (combined procedure) are currently lacking. Purpose To compare acute and long-term outcomes between stand-alone LAAC vs a LAAC+CB-PVI combined procedure. Methods All patients undergoing LAAC at our institution, having at least 2 years follow-up, were analyzed to assess the impact of additional CB-PVI. The primary efficacy and safety endpoints of our study were the acute procedural success rate and the peri-procedural complications rate. As secondary endpoints, major bleeding, and ischemic events, as well as sinus rhythm rate at 2 years follow-up were assessed. Results Among 126 LAAC patients meeting inclusion criteria (males=64.2%), n=55 (43.7%) underwent a combined procedure. LAAC-only patients were older (72.5±7.2 vs 68.9±8.6, p&amp;lt;0.05) and less frequently having paroxysmal AF (23.9% vs 47.3%, p&amp;lt;0.05). Baseline CHA2DS2-VASc was similar among groups (3.3±1.3 vs 2.9±1.1, p=0.07) while LAAC-only patients had higher HAS-BLED at enrollment (3.4±1.1 vs 3.0±1.0, p=0.04). Additional CB-PVI was not a risk factor for incomplete LAA occlusion (OR 0.24–3.78, p=0.96), presence of residual lateral flow (OR 0.26–4.05; p=0.96), intraprocedural need for occluder device resizing compared to pre-procedural assessment (OR 0.27–3.05; p=0.884), and peri-procedural complications (OR 0.25–6.74, p=0.749). At 3-month post-procedural trans-esophageal echocardiography, a combined procedure was not associated with higher risk of incomplete occlusion (OR 0.33–1.59, p = 0.432), nor larger peri-device leakages (coefficient k: -0.65–+0.20, p=0.291). Overall and by-group ischemic (red) and bleeding (blue) relative risk reduction from CHA2DS2-VASc and HAS-BLED predicted yearly rates during follow-up was reported in Figure1. Over a median follow-up of 40 [26–56] months, a combined procedure was not a risk factor for major bleeding (OR 0.31–5.48, p=0.715) or ischemic (OR 0.11–3.56, p=0.599) events. As expected, additional CB-PVI was strongly associated with a reduction of AF recurrences (OR 0.16–0.86, p&amp;lt;0.05), after excluding permanent AF patients from the analysis. Conclusion Combined LAAC + CB-PVI procedure does not appear to be a risk factor for worse LAAC-related outcomes, while reducing AF recurrences in non-permanent AF patients.Figure 1

Weight change does not impact the long-term outcomes following pulmonary vein isolation in obese patients with atrial fibrillation

Abstract Background Weight loss has been shown to reduce the burden of atrial fibrillation (AF) in obese patients. However, there are limited data on the impact of weight loss on long-term outcomes in patients with atrial fibrillation (AF) who undergo pulmonary vein isolation (PVI). Objective To understand the impact of weight change, as assessed by freedom from recurrent AF, in obese patients undergoing cryoballoon (CB) PVI. Methods We enrolled consecutive obese (BMI ≥ 30 kg/m2) patients with AF who underwent CB PVI; all patients had an implantable loop recorder (ILR) for long-term ECG monitoring. The cohort was divided into 3 groups based on their weight change 1-year after ablation: (1) weight loss (WL) &amp;gt; 3% weight decrease; (2) no weight change (NWC) - weight change &amp;lt; 3%, (3) weight gain (WG) &amp;gt; 3% weight increase. We assessed long-term AF recurrences, after excluding an initial 3-month post-ablation blanking period. Results Out of total of 137 pts with obesity, 61 pts had weight available at the ablation and at 1-year follow-up (65 ± 9 years; 41 [67%] male; 23 [38%] PAF; CHA2DS2-VASc 2.9 ± 1.7). There were no differences in baseline characteristics. At follow-up, 24 (39%), 26 (43%), and 11 (18%) pts lost, had no change, or gained weight, respectively. Of the 24 pts who lost weight, 3 pts lost &amp;gt; 10% body weight. During a follow-up of 964 ± 512 days, 41 (67%) pts had recurrent AF; the change in weight did not impact outcomes (Figure), including those who lost &amp;gt; 10% body weight. Conclusions During 3-years of follow-up, 2/3 of obese patients had objective evidence of AF recurrence following CB PVI. Weight change in the first-year post ablation did not alter long-term outcomes. Other strategies may be needed in these patients to improve outcomes.

Treatmen of atrial fibrillation with cryoballoon pulmonary vein isolation - results of a 5-year follow-up

Abstract Background Atrial fibrillation is the most common arrhythmia in the general population and cryoballoon ablation is gradually becoming a first-line treatment. However, data regarding long-term outcomes after this procedure are still lacking. Aim The goal was to show the results of a long-term follow-up following the cryoballoon pulmonary vein isolation in patients with atrial fibrillation (AF). Methods A total of 126 patients were included in the study of which 77.0% had paroxysmal atrial fibrillation (PAF). Successful treatment outcome was defined as AF recurrence-free survival with stabile sinus rhythm during 5 years after the procedure. A treatment failure was defined as symptomatic AF recurrence with ECG verification (12 lead ECG or AF lasting &amp;gt;30s by Holter EKG). The patients on antiarrhythmic therapy and those who underwent a redo pulmonary vein isolation procedure were also included. Results Following cryoballoon pulmonary vein isolation in a 5-year period 52.4% of patients were in stable sinus rhythm without AF recurrence. With redo pulmonary vein procedures a total of 61.9% of patients were without AF recurrence. Together with antiarrhythmic drugs 57.9% of patients were in sinus rhythm without AF recurrence in a 5-year period. With redo pulmonary vein isolation and antiarrhythmic drugs a total of 73.8% of patients were without AF recurrence. There was a statistically significant difference regarding AF recurrence between patients who underwent redo pulmonary vein isolation and those who did not (p=0.006). In patients with PAF, 62.9% remained without AF recurrence, and 79.4% underwent a redo procedure. In patients with persistent atrial fibrillation (PersAF), 41.4% were without AF recurrence, and 55.1% underwent a redo procedure. The difference between PAF and PersAF was statistically significant (p=0.009). Conclusion Data from our center show good long-term results of cryoballoon pulmonary vein isolation in patients with atrial fibrillation. The procedure is especially successful in patients with PAF.1 The use of redo procedures is justified as it increases the long-term success rate.

Effectiveness of cryoballoon ablation for atrial fibrillation in patients with left common pulmonary vein variant: insights from a national multicenter catheter ablation registry

Abstract Background Pulmonary vein isolation (PVI) is the most effective therapy to achieve rhythm control in atrial fibrillation (AF). Yet, data regarding the safety and effectiveness of this procedure in left common pulmonary vein (LCPV) variant is limited. Purpose To explore the effectiveness of cryoballoon AF ablation in patients with LCPV variant. Methods A prospective cohort, based on a multicenter registry that included patients who underwent PVI during the years 2019-2021. The study end points were acute isolation success of the pulmonary veins (PVs), AF recurrence and the need for a repeat ablation procedure at 12 months. Results Seventy-four patients with LCPV variant and 822 patients with standard four pulmonary veins (PVs) were included in the study cohort. The acute isolation success rates of the left pulmonary veins were significantly lower in the LCPV variants compared to the standard 2 left PVs; 95.9% versus 98.9% respectively (P=0.03). The acute isolation success rates of the right pulmonary veins were not different among patients with LCPV versus standard anatomy; 98.6% versus 98.5% respectively (P=0.9). The rates of AF recurrence at 12 months were numerically higher in the LCPV variant compared to the standard anatomy group; 17.6% versus 11.1% respectively, but did not reach statistical significance (P=0.09) (Figure 1). The rates of repeat ablation did not differ between the study groups; 8.1% versus 6.2% respectively (P=0.51) (Figure 2). Conclusion In our study cohort, the acute isolation success rate of the LCPV was significantly lower compared to standard two left PVs, this finding emphasizes the challenge of isolating LCPV variants using cryoballoon PVI. However, in spite of the lower isolation success rates in the LCPV variants, the clinical effectiveness to prevent AF recurrences was preserved.Figure 1Figure 2

Impact of the timing of early recurrences during the blanking period in patients after cryoballoon ablation: insights from the COMPARE CRYO study using continuous rhythm monitoring

Abstract Background Early recurrences (ER) during the blanking period after pulmonary vein isolation (PVI) are common. While many of those correlate to late recurrences (LR) after the blanking period, some do not. The impact of the timing of ER is difficult to assess with non-invasive Holter monitoring due to under sampling. Purpose To evaluate the impact of the timing of ER after cryoballoon ablation using continuous rhythm monitoring by means of an implantable cardiac monitor (ICM). Methods This is a prespecified sub study of the COMPARE-CRYO study. The trial enrolled patients with paroxysmal atrial fibrillation and compared PVI with the PolarX cryoballoon and the ArcticFront cryoballoon. All patients underwent ICM implantation at the end of the PVI. ER was defined as recurrence of any atrial arrhythmia &amp;gt; 30 seconds between days 0-90 after PVI. LR was defined as recurrence of any atrial arrhythmia &amp;gt; 30 seconds between days 91-365. Results ER occurred in 116 of 201 patients (58%). A total of 5330 episodes occurred, 4210 in patients with LR and 1120 in patients without LR (Figure 1A). Median time to the latest episode of ER in the blanking period was 18 days (IQR 8.5-36.5) in patients with no LR and 80 days (IQR 27-89) in patients with LR (p&amp;lt;0.001). The latest episode of ER occurred between days 0-30, 31-60 and 61-90 in 41%, 13% and 46% of patients respectively. Freedom from recurrence of atrial arrhythmias 1 year after the PVI was 81% in patients without ER and 37% in patients with ER (p&amp;lt;0.001, Figure 1B). When patients were classified according to their latest episode of ER occurring between days 0-30, 31-60 and 61-90, freedom from any atrial arrhythmia at 1 year was 60%, 53% and 11% (p&amp;lt;0.001, Figure 1C) respectively. ROC analyses revealed a strong correlation of LR with the timing of the latest episode of ER in the blanking period (AUC=0.81, p&amp;lt;0.001) with an optimal cutoff value at 61 days (SN 64%, SP 88%). Median AF burden in the blanking period was 0% (IQR 0-0) in patients with ER but no LR and 0.2% (IQR 0-2) in patients with ER and LR (p&amp;lt;0.001). This was similarly true for all individual months (0-30 days: 0% vs. 1.8%, p&amp;lt;0.001, 31-60 days: 0% vs. 0.1%, p&amp;lt;0.001, 61-90 days: 0% vs. 0.1%, p p&amp;lt;0.001). There were no differences in the duration of ER episodes or in clinical characteristics between patients with and without LR Conclusion ER after cryoballoon PVI is common. While ER during the first and second month after PVI disappear in the majority of patients, presence of ER in the third month after PVI are highly predictive for ablation failure.

An enhanced and objective approach to advancing the classification system for left atrial appendage morphology in atrial fibrillation

Abstract The left atrial appendage (LAA) is an important part of the heart that can contribute to the formation of blood clots and the development of arrhythmias. Managing the LAA is crucial in clinical practice. Besides oral anticoagulation, one approach is LAA occlusion, which can reduce the risk of blood clots in selected patients. Another approach is LAA ablation, which has been proposed in addition to pulmonary vein isolation (PVI) and might improve the success of treating atrial fibrillation (AF). Different types of LAA morphology have been identified, and these differences can affect the choice of treatment and strategies for individual patients. To refine current classification system, a new approach has been proposed. The study utilized an observational single-center trial with blinded retrospective analysis of cardiac computed tomography angiography (CCTA) images from cryoballoon PVI patients. Statistical analysis included baseline characteristics and left atrium/LAA measurements. An LAA bounding box was introduced to enhance the current classification system, particularly focusing on distinguishing "chicken-wing" and "windsock," as well as "cauliflower" and "cactus" morphologies. From 2012 to 2016 a total of 1.103 patients underwent second generation cryoballoon PVI. Prior to PVI, CCTA was available for 725 (65.7%) patients with sufficient quality for measuring in 473 (65.2%). Mean age was 66.3±9.5 years; Paroxysmal AF was present in 277 (58.6%) participants. The distribution of LAA morphological types was as follows: "windsock" 51%, "chicken-wing" 20%, "cauliflower" 15%, and "cactus" 13%. Inter-rater reliability, assessed using Cohen's Kappa with Landis and Koch criteria, demonstrated substantial agreement (Kappa = 0.69; p&amp;lt;0.001). "Chicken-wing" morphology had the largest LAA volume at 9.9 (7.9; 12.8) mL, followed by "windsock" morphology with an LAA volume of 9.7 (7.7; 13.1) mL. "Cactus" and "cauliflower" morphologies had considerably smaller LAA volumes, measuring 5.4 (4.6; 7.5) mL and 5.6 (4.4; 7.6) mL, respectively. Bounding box parameters were utilized to distinguish between "windsock" and "chicken-wing" as well as "cauliflower" and "cactus" morphologies. "Windsock" had a maximal LAA depth of 44.3±7.1 mm, while "chicken-wing" measured 40.1±8.6 mm (p&amp;lt;0.001). The sinus values for the bounding box were 0.40±0.06 for "windsock" and 0.44±0.08 for "chicken-wing" (p&amp;lt;0.001). For "cauliflower," the LAA depth averaged 30.42±5.0 mm, whereas for "cactus," it measured 33.4±4.3 mm (p&amp;lt;0.001). The mean sinus of the bounding box was 0.48±0.08 for "cauliflower" and 0.44±0.07 for "cactus" (p&amp;lt;0.05). The utilization of novel bounding box parameters has the potential to aid in the differentiation between different LAA morphologies, such as 'chicken-wing' and 'windsock', as well as 'cactus' and 'cauliflower', especially in cases where the current classification system may not provide clear distinctions.

Artificial intelligence-estimated electrocardiographic age as a recurrence predictor after atrial fibrillation catheter ablations

Abstract Aims The application of artificial intelligence (AI) algorithms to 12-lead electrocardiogram (ECG) provides promising age prediction models. We explored whether the gap between the pre-procedural AI-ECG age and chronological age can predict atrial fibrillation (AF) recurrence after catheter ablation. Methods We validated a pre-trained residual network (ResNet)-based model for age prediction on four independent multinational datasets: CODE-15%, PTB-XL, UK Biobank, and SaMi-Trop cohorts. Then, we evaluated AI-estimated ECG (AI-ECG) age for AF recurrence in a single-center AF catheter ablation (AFCA) cohort, which included 4,794 patients with de-novo AFCA and pre-procedural sinus rhythm ECGs. We categorized the AI-ECG age gap into two groups: aged-ECG (&amp;gt;13 year) and normal age (≤13 year) groups based on the maximum log-likelihood for AF recurrence according to the difference between chronological age and AI-ECG age. Results The ResNet-based AI-ECG age model successfully reproduced the chronological age on the independent datasets (total ECG number=414,804): CODE-15% (r=0.83), PTB-XL (r=0.74), UK Biobank (r=0.53), and SaMi-Trop (r=0.60). During median 22 (9-47) months after AFCA, patients with aged-ECG had a significantly higher AF recurrence rate (adjusted hazard ratio 1.31, 95% confidence interval [1.17-1.48], p&amp;lt;0.001) than normal age group. In the sub-group analyses, the aged-ECG affected more in patients with paroxysmal AF than in non-paroxysmal AF (P for interactions &amp;lt;0.001) and after cryoballoon pulmonary vein isolation (Cryo-PVI) than radiofrequency PVI (P for interactions &amp;lt;0.001). Conclusions Pre-procedural AI- ECG age has a prognostic value for AF recurrence after AF catheter ablation.

Impact of age on atrial arrhythmia recurrence following cryoballoon pulmonary-vein isolation

Abstract Background Age is a major risk factor for development of atrial fibrillation (AF) and associated with increased recurrence rates in the setting of rhythm control. Current data tend to support catheter ablation in elderly patients, but it remains unclear whether there is an age limit for ablation and whether the potential benefits of catheter ablation justify the potentially increased complication rate in elderly. Objective To prospectively analyze the impact of age on efficacy and safety of cryoballoon ablation (CBA). Methods ; We prospectively analyzed consecutive patients who underwent CBA in a single-center cohort between 2018 and 2023. Patients were stratified by age (&amp;lt;75yrs versus ≥75yrs) and AF type. Primary efficacy endpoint was recurrence of atrial arrhythmia after 90-day blanking period. Linear and spline regression were used to assess the association between age and primary efficacy endpoint. Safety endpoints were death, stroke or procedure-related complications. Results 873 patients underwent CBA (525 paroxysmal, 348 persistent AF). Median follow-up was 18-months. At 1-year, primary efficacy endpoint occurred in 19.6% (71/363) of young (&amp;lt;75yrs) versus 27.8% (45/162) of elderly (≥75yrs) patients with paroxysmal AF (HR 0.62; 95%CI, 0.41-0.92; P=0.019; fig. 1A) and in 25.0% (57/228) of young versus 39.2% (47/120) of elderly patients with persistent AF (HR 0.57; 95%CI, 0.37-0.85; P=0.006; fig. 1B). A significant linear relationship between age and primary efficacy endpoint occurrence was found for both paroxysmal (P=0.01) and persistent AF (P=0.002; fig.2) while spline regression was non-significant (P=0.45/ P=0.12). No difference was observed regarding the incidence of safety endpoints between young and elderly patients (P=0.76). Conclusion Atrial arrhythmia recurrence rate after CBA increases linearly with age (thus not allowing determination of a clear "cut-off-age") and is highest in elderly patients (≥75 yrs) with persistent AF. Safety of CBA in elderly is comparable to patients of younger age.

Long-term impact of multiple freezes during cryoballoon pulmonary-vein isolation on atrial arrhythmia recurrence

Abstract Background Cryoballloon pulmonary vein isolation (CryoPVI) is well established for atrial fibrillation (AF) ablation. Nevertheless, it is still important to identify possible periprocedural factors influencing its efficacy. With difficult anatomical conditions it is currently unclear whether the number of cryoballoon applications needed to achieve complete vein isolation has an impact on the long-term effectiveness of CryoPVI. Methods We prospectively analyzed AF patients who underwent first-time CryoPVI in a single center cohort between 2018-2023. The group allocation depended on the number of cryo applications until complete isolation was achieved. CryoPVI was performed in a standardized procedure. Follow-up was performed after 3, 6, 12, 18, 24 and 36 months post CryoPVI. Efficacy endpoint was the occurrence of symptomatic atrial arrhythmia. Results A total of 1170 patients were included in the study. Of these, in 610 patients received only one cryoballoon application per pulmonary vein to achieve complete isolation. Gender distribution (56.7% male vs. 43.3% male p=0.09) and AF phenotype (38.5% persistent AF vs. 61.5% paroxysmal AF, p=0.23) did not differ significantly between the two groups, patients who received only cryoballoon application were older (70.1 vs. 68.5, p=0.006) and accordingly had higher CHADS-VASc (2.86 vs. 2.62, p=0.006). After 36 months no difference in the efficacy endpoint was observed between the two groups (47.6% vs. 43.2%, p=0.53). Complications included three major access complications (0.5% vs. 0.5%) and one stroke within the first 30 days after the procedure (0.2% vs. 0.2%) in each group. No pericardial tamponade occurred. Conclusion Multiple- freezes during CryoPVI have no influence on atrial arrhythmia recurrence.

Intelligent filter to remove artifact during cryo freezing for pulmonary vein isolation increases the time window for observation of time of isolation

Abstract Introduction Time to pulmonary vein isolation (PVI) during cryo balloon (CB) PVI is a critical data point in characterizing the pulmonary vein (PV) isolation status as it improves clinical outcomes. PV potentials on the circular mapping catheter may be obscured by power line artifact during the freeze process as ice forms near the electrode. This study assesses the ability of an intelligent digital filter to sample, predict and remove noise from PV electrograms during the freeze cycle to increase the time window available to observe the abolition of PV potentials. Method An intelligent filter that detects and removes power line related signal artifact was developed. The filter algorithm was then retrospectively applied to electrograms collected during delivery of cryo energy in the PVISION trial of the PVI Analyzer study previously described. The PV potential amplitude immediately before the delivery of cryo energy was recorded. During the freeze cycle, artifact amplitude was measured and the time required for the noise to exceed that of the original PV potential recorded. This operation was repeated with the application of the predictive filter. An example of an analysis of a single bipolar trace is shown in Fig 1. Results The PVISION trial included 47 patients who underwent a cryo PVI procedure (42% female, mean age 59 years, +/- 11 years). Of those, 24 cases and 68 vein cryo applications had sufficient information about when the cryo freeze cycle started and ended. Of these 68 veins treated, 33 exhibited power line noise on one or more bipolar traces during the freeze cycle (49%). The mean amplitude of PV potentials before application of energy was 0.49 mV (+/- 0.79 mV) and the mean time to artifact exceeding this level was 69 (+/-50 seconds), across all bipolar traces with freeze noise present. After application of the intelligent filter, the mean time to artifact exceeding the baseline PV amplitude increased to 82 seconds (+/- 57 seconds), across all bipolar traces with freeze noise present. In 44 veins noise amplitude never exceeded PV potential amplitude on any of the bipolar traces during the freeze after application of the intelligent filter. Paired analysis of the average time of noise exceeding the PV potential amplitude during the freeze was 116 s before application of the filter and 26 s with the filter applied. See Fig 2. for a summary of the results. Conclusion An intelligent digital filter designed to remove artifact from electrograms during cryo ablation procedures might increase the time window before noise saturates PV potentials and, in some cases, remove noise such that it never exceeds that of the PV potential.Fig 1 Example of noise and filteringFig 2. Summary of results

Superior vena cava isolation in paroxysmal atrial fibrillation - mind the phrenic

Abstract Background Pulmonary vein isolation (PVI) is the standard of care for patients with atrial fibrillation (AF), but medium-term success rates are far from ideal. Therefore, new methods are being developed, with emphasis on ectopic foci outside the pulmonary veins. Superior vena cava (SVC) is one of the most important non-pulmonary origins of AF and some studies suggested that empiric SVC isolation could improve outcomes in ablation of paroxysmal atrial fibrillation (PAF). Although complications have been reported in SVC ablation, most studies found complication rates of SVC ablation similar to conventional cryoballoon PVI. Aim This prospective, single-center study aimed to assess the complication rate and success rate of PVI followed by SVC isolation by cryoballoon application in comparison with conventional cryoballoon PVI. Methods We designed an unblinded, randomized clinical trial and recruited consecutive patients with PAF who were randomized to a conventional cryoballoon PVI or PVI and additional SVC cryoballoon isolation using single 180 s freeze. Results A total of 140 patients (61.4% male, mean age 62.1 years) with PAF were included and 67 (47.9%) were randomized to SVC isolation in addition to conventional ablation. Planned 180-s freeze in the SVC could be completed in 15 (22.4%) patients, while 27 (40.3%) patients received at least 120-s freeze. The mean time to SVC isolation was 40.2 ± 37.9 s. Real-time recording of SVC isolation was observed in 39 (58.2%) patients. Right phrenic nerve palsy (PNP), impending or transient, occurred in 6 (8.2%) patients in the PVI-only group and in 25 (37.3%) patients in the SVC-group (Chi-square test p &amp;lt; 0.001). There were no persistent PNP cases. Bradycardia or junctional rhythm was observed during a procedure in 15 (22.4%) patients who received SVC isolation. One patient eventually received a permanent AAI pacemaker due to a sinus node injury. Conclusion Our data suggest that SVC isolation can be successfully achieved in the majority of PAF patients using conventional cryoballoon. However, this significantly increases the rate of transient or impending PNP and sinus node injury in comparison to conventional cryoballoon PVI. Therefore, careful phrenic nerve function monitoring and attention to sinus bradycardia or junctional rhythm are important to mitigate this risk. Follow-up data are being collected to determine whether this risk could be outweighed by a lower rate of PAF recurrence.

One shot "fire &amp; ice"

Abstract Introduction Pulmonary vein isolation (PVI) is the best and first strategies during ablation of atrial fibrillation (1-4). Short- and long-term effectivity as well as procedure time are important parameters during PVI-ablation. New efforts are made to find longer effectivity, low risk of the procedure and shorter procedure. Purpose The aim of our study is to compare the two "balloon - one shot" methods (radiofrequency balloon "RFB" and cryoballoon "CB") in terms of speed, efficacy and safety. Methods Prospective, randomized, pilot single-center trial including 74 consecutive patients with paroxysmal, persistent or long lasting persistent atrial fibrillation who undergo for the first time PVI-ablation between December 2022 and October 2023. Patient were randomized 1:1 according type of AF, Sex, Hypertension, left ventricular ejection fraction e left atrial volume in a multi-electrode radiofrequency balloon catheter Heliostar ablation or in cryoballoon system ablation. Both groups had comparable clinical characteristics. Results Median Age of the population was 64 year (iq range 57-70), 19 were female (25,7%), 31 patients (42%) had paroxysmal atrial fibrillation, median EF was 60% (iq range 55-65) and median left atrial volume 36 ml/mq (iq 28-40). 37 patients undergo cryoballoon PVI and 37 patients undergo RF balloon Ablation. Compared with the RFB group, the CB group showed a shorter procedure time [65 minutes (55-75) vs. 75 minutes (65-90) (P &amp;lt; 0.008)]. The DAP (dose area product) was lower in RFB Group [7 Gy*cm2 ( 5-10) vs CB Group 11 ( 7-18), p&amp;lt;0,001]. First-pass isolation was comparable. We had 5 complications in RFB group (1 pericardial effusion without pericardiocentesis, 3 transitory ST-elevation on ECG due to air embolism, 1 transient phrenic nerve palsy) and 3 complications in CB group (3 transient phrenic nerve palsy) P=ns. During the procedures in 3 cases of RF group and in 1 case of CB group (p=ns) we had to change the balloon due to technical issues. Conclusion The RFB appears to have a safety and efficacy profile similar to that of the CB for PVI. CB has shorter procedural times but with a higher X-Ray exposure.Figure 1Figure 2

Impact of early atrial arrhythmia recurrence on long-term CryoPVI success

Abstract Background According to current guidelines, the occurrence of atrial fibrillation (AF) recurrence within the first 90 days after pulmonary vein isolation (PVI) should not indicate re-do procedures. Accordingly, a 90-day blanking period is usually accepted. However, data suggests that early atrial arrhythmia relapses during the blanking period have an impact on the efficacy. The optimal period for indicating a re-ablation therefore remains unclear. Methods We prospectively analyzed consecutive AF patients who underwent cryoballoon PVI (CryoPVI) in a single-center cohort between 2018 and 2023. We divided patients into four groups according to arrhythmia recurrence (recurrence between 0-30 days, recurrence between 30-60 days, recurrence between 60-90 days and no recurrence within the first 90 days). CryoPVI was performed in a standardized procedure. At 3, 6, 12, 18, 24 and 36 months after CryoPVI follow up was performed. Efficacy endpoint was the occurrence of symptomatic atrial arrhythmia relapse. Results During the study period 1179 patients underwent a first CryoPVI. Of these, 84 patients (7.1%) had atrial arrhythmia relapse between 0-30 days, 38 patients (3.2%) had atrial arrhythmia relapse between 30-60 days, and 38 patients (3.2%) had a relapse between 60-90 days. Overall, 1019 (86.4%) patients didn’t have an atrial arrhythmia relapse between 0-90 days after CryoPVI. Primary efficacy endpoint incidence after 36 months was significantly higher in patients who experienced atrial arrhythmia relapse within the first 90 days (between 0-30 days 62.5% vs. between 30-60 days 70.1% vs. between 60-90 days 77.9% vs. no recurrence ≤ 90 days 41.6%, p&amp;lt;0.0001). Conclusion Atrial arrhythmia relapse within the first 90 days is associated with a reduced long-term efficacy of CryoPVI. Re-ablation should be indicated regardless of the time of recurrence.

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.