Cryoablation For Atrial Fibrillation Research Articles

Assessing the impact of 3D imaging assistance on efficiency and safety in atrial fibrillation cryoablation

Abstract Introduction Pulmonary vein (PV) isolation is a cornerstone therapy for symptomatic atrial fibrillation (AF). Current 3D-navigation technologies used with radiofrequency (RF) ablation allow drastic reduction of X-ray exposure and better anatomical characterization improving acute and long-term procedural results. Cryoballoon ablation (CA) procedures typically rely on conventional fluoroscopy, resulting in significant X-ray exposure. Although contemporary fluoroscopy technologies allow for potential 3D imaging integration, their specific utility in improving procedural guidance during CA remains undefined. Method Using semi-automatic segmentation obtained from pre-procedural cardiac computed tomography, 3D segmentations of the left atrium, including PV, spine and primary bronchi walls were fused on the real-time fluoroscopy acquisitions in three standard positions (AP, LAO, RAO), acquired at the beginning of the procedure (Figure1). We compared procedural characteristics of CA performed with 3D-fusion imaging to conventional fluoroscopy-guided procedures. Results Thirty-six patients (aged 60±13 yo, 85% male) with paroxysmal AF treated with CA were included in the study: 18 in the control group (conventional fluoroscopy) and 18 in the 3D-assisted group. Acute PV isolation was achieved in all patients. The 3D-assisted CA was associated with significantly shorter procedure duration (mean 97.8±15.5 vs 82.1±16.1 min, p=0.0048); left-sided dwelling time (mean 77±15.2 vs 65.1±14.4 min, p=0.0351); and lower X-ray energy delivered to the patient (Dose Area product) with mean 661±373.1 vs 378.1±316.8 cGy*cm2 (p=0.013). Interestingly, we found that 72.2% of 3D guided procedures were done in less than 90min, while 77.8% of conventional cases required more than 90min to be completed (Figure 2D). Conclusion 3D-fusion imaging integration is feasible and allows for an exact PV anatomy depiction on fluoroscopy. Our data illustrates that it might significantly improve CA efficiency (shorter procedure duration) and safety (lower X-ray exposure and left-sided dwelling time). Our approach could also impact long-term results since it might reduce the likeability of missing intermediate PVs. Further research is needed to evaluate the incremental value of 3D imaging in long term efficacy.Figure 1Figure 2

The impact of additional radiofrequency ablation for atrial fibrillation substrates using with ExTRa-Mapping analysis after Cryo-ablation in patients with persistent atrial fibrillation

Abstract Background Pulmonary vein isolation (PVI) for persistent atrial fibrillation (AF) is well established. Cryo-ablation for persistent AF has been reported to be safe and effective and comparable to radiofrequency (RF) ablation in long term arrhythmia-free survival, but the outcome is limited. Phase mapping using software of ExTRa-Mapping is a new tool to clarify the real-time imaging of the AF wave dynamics. Purpose We investigated the distribution of rotors of left atrium (LA) after PVI by Cryo-ablation, and the efficacy and safety of additional RF ablation for AF substrates (rotor modification) after Cryo-ablation. Methods A total of 50 patients who underwent persistent AF ablation in our hospital were enrolled. The Cryo-ablation alone group (Cryo group; n=25) and the Cryo-ablation + additional RF substrates ablation group (Cryo+RF group; n=25) were randomly divided. First, PVI with Cryo-ablation was performed. Second, if AF did not term after PVI, the rotor of LA were analyzed using the NAVX and ExTRa-Mapping system. In Cryo+RF group, the extensive RF ablation of the PV antrum to modify the rotor area were performed (Abstract Picture 1). The recurrence rate of any atrial tachy-arrhythmia without anti-arrhythmic drugs and safety were evaluated in both groups. Results The patient characteristics (69 ± 9.2 years old, body-mass index 24 ± 3.2 kg/m2, LA diameter 43 ± 5.1 mm, left ventricular ejection fraction 60 ± 7.8 %, persistent AF duration 4.2 ± 5.1 months) did not differ between the both groups. The distribution of rotors of LA were predominantly present in the anterior (n = 36) and inferior (n = 27) walls of the LA, with only a few in the posterior wall (n = 7) in the both groups. In Cryo+RF group, except for 4 cases in which AF was termed by PVI or a rotor was not detected, extensive RF modification in anterior antrum of right pulmonary vein was performed in 18 of 21 cases. In an average follow-up of 482 ± 273 days, the recurrence rate of any atrial tachy-arrhythmia was significantly lower in Cryo+RF group compared with Cryo group (p=0.029, Abstract Picture 2). No serious complications occurred in both groups. Conclusion Additional extensive RF ablation of the PV antrum to modify the Rotor area resulted in a lower recurrence rate in patients with persistent AF.Modify the rotor areaRecurrence rate

Atrial fibrillation cryoablation guided by pulmonary vein pressure: comparison with the standard strategy

Abstract Background Pulmonary vein (PV) isolation is the cornerstone for the treatment of patients with atrial fibrillation (AF). Balloon cryoablation (BCA) is the preferred single-shot option for ablation of PVs using contrast guided occlusion as the standard approach (SA). We have made a simplified procedure, using a pressure-guided approach (PG) aimed to obtain a PV wedge curve. This technique has been described previously(1-3). To our knowledge, no comparison has been made in real life with a mixed patient setting in AF (paroxysmal and persistent) and non-selected anatomy with exclusive PG. Purpose To compare a prospective cohort of patients going into AF BCA, using SA versus PG. Methods Between January 2022 and October 2023, 50 consecutive patients underwent BCA. The first 25 patients were treated with SA protocol and the latter 25 with PG. In both techniques, the aim was to obtain PV isolation with a 240 seconds application and no bonus attempt. A computed tomography angiography or MRI of the left atrium (LA) was performed in all the patients. 28-mm Cryoballoon and Intracardiac echo were used in all the procedures. We compared patients and procedure characteristics between both techniques. Results Both groups (SA vs PG) showed similar baseline characteristics with not significant differences between them: mean age (58±10 vs 61±10 years), median LA diameter (40±8 vs 41±5mm), mean LVEF (60±9 VS 63±7%), Paroxysmal AF (60 vs 56%), average CHA2DS2-VASc score (1.3±1.3 vs 1.8±1.5), One patient is SA group had a previous radiofrequency (RF) ablation with 4/4 veins reconnected, and in the PG group two patients had RF ablation with 7/8 veins reconnected (Table 1). The procedural characteristics between SA and PG, also did not show significant differences: median procedural time (120±20 vs 130±38 min), fluoroscopic time (24±13 vs 30±19 min), and isolation was achieved in 98/99 veins (99%) in each group (Table 2). In the SA group, two patients had complications: one patient with a transient palsy of the phrenic nerve and because of this, only 3/4 veins were targeted, and the second patient had a post-procedure pericarditis. In the PG group, one patient had a pericardial effusion seen at the end of the procedure that did not require drainage. Conclusion In our initial experience, BCA for AF with both strategies proved to be safe and effective in this mixed group with non-selected anatomy. This result reassures the PG as a way to enhance CBA because of the advantage in avoiding the use of intraprocedural IV contrast. Impact in performance during follow-up is yet to be seen in our cohort.Table 2.Baseline characteristicsTable 2.Procedural characteristics

Atrial fibrillation cryoablation guided by pressure waveform: a prospective multicentre registry

Abstract Background Cryoballoon ablation (CA) procedures require optimal occlusion of the pulmonary veins (PV), which is conventionally evaluated by iodine contrast injection through the catheter tip. This technique has some weaknesses such as risk of allergic reactions, nephrotoxicity, requirement of fluoroscopy (sometimes at high doses), requirement of a second operator, among others. PV pressure waveform assessment is an alternative method for confirming occlusion, however, multicentre assessment of periprocedural efficacy and safety is lacking. Purpose To describe the intra-procedural performance and safety of routine pressure-based CA. Methods In this independent prospective multicentre observational study, baseline and procedure data from consecutive pressure-guided CB ablations were collected. Operators were not required to have experience in pressure-guided CA for participating in the registry. They were asked to classify the pressure waveform curves into type 1 (presence of "a-wave" and/or symmetric "v-wave", meaning incomplete PV occlusion) and type 2 (absence of "a-wave" and asymmetric "v-wave", meaning complete PV occlusion), Figure 1. The primary endpoint was PV isolation in all veins without use of contrast. Procedure performance and adverse events were also analyzed. Results A total of 150 patients (mean age: 61 ± 10 y.) with paroxysmal (62%) or persistent AF (38%) were included and underwent pressure-guided CA in 9 centres from Spain. Complete PV isolation was achieved in 148 patients (98%). The operators switched to contrast use in 14 cases (9%), mainly to double check the occlusion. Total procedure and fluoroscopy time were 97 ± 39 and 19 ± 10 min respectively. There were 7 (4.7%) procedure related adverse events: 4 phrenic nerve palsy (3 of them were transient), 1 transient coronary ST elevation (before ablation), 1 gastroparesis and 1 femoral pseudoaneurysm. Most relevant results are summarized in Figure 2. Conclusion In this multicentre and multi-brand assessment, CA guided by pressure waveforms provided outstanding procedural outcomes, which were equivalent to those reported with the conventional approach. All operators could easily obtain and identify the waveform without a specific learning curve, avoiding the use of iodine contrast in most cases. The long-term efficacy of this approach will be presented in future analyses.Pressure waveforms types in cryoablationProcedural data

Cryoablation of atrial fibrillation in "very severe" obese patients (BMI ≥ 40): Indications, feasibility, procedural safety and efficacy, and clinical outcome (the ICE-Obese Extreme).

Management of atrial fibrillation (AF) in very severe obese patients is challenging. Cryoballoon ablation (CBA) represents an effective rhythm control strategy. However, data in this patient group were limited. Highly symptomatic AF patients with body mass index (BMI) ≥ 40 kg/m2 who had failed antiarrhythmic drug therapy and electrocardioversion and failure to achieve targeted body-weight-reduction underwent CBA. Data of 72 very severe obese AF patients (Group A) and 129 AF patients with normal BMI (Group B, BMI < 25 kg/m2) were consecutively collected. Group A had significantly younger age (60.6 ± 10.4 vs. 69.2 ± 11.2 years), higher BMI (44.3 ± 4.3 vs. 22.5 ± 1.6 kg/m2). Procedural pulmonary vein isolation (PVI) was successful in all patients (2 touch-up ablation in Group A). Compared to Group B, Group A had similar procedural (61.3 ± 22.6 vs. 57.5 ± 19 min), similar fluoroscopy time (10.1 ± 5.5 vs. 9.2 ± 4.8 min) but significantly higher radiation dose (2852 ± 2095 vs. 884 ± 732 µGym2). We observed similar rates of real-time-isolation (78.6% vs. 78.5%), single-shot-isolation (86.5% vs. 88.8%), but significantly longer time-to-sustained-isolation (53.5 ± 33 vs. 43.2 ± 25 s). There was significantly higher rate of puncture-site-complication (6.9% vs. 1.6%) in Group A. One-year clinical success in paroxysmal AF was (Group A: 69.4% vs. Group B: 80.2%; p < .001), in persistent AF was (Group A: 58.1% vs. Group B: 62.8%; p = .889). In Re-Do procedures Group A had a numerically lower PVI durability (75.0% vs. 83.6%, p = .089). For very severe obese AF patients, CBA appears feasible, leads to relatively good clinical outcome.

Efficacy of cryoablation in atrial fibrillation: comparison with antiarrhythmic therapy.

Atrial fibrillation (AF) represents the most common arrhythmia in clinical practice, characterized by irregular atrial electrical activity originating mainly in and around the pulmonary veins. This condition can manifest itself symptomatically or silently but still dangerously. Complications associated with AF include stroke, heart failure, worst clinical outcome in patients with underlying conditions, increased emergency room visits, hospitalizations, and cardiovascular mortality. Currently, according to the main international guidelines, antiarrhythmic therapy is considered the first choice for rhythm control in patients with AF despite modest efficacy and non-negligible side effects. In recent decades, radiofrequency catheter ablation has emerged as an alternative to antiarrhythmic drugs for rhythm control. Cryoablation was developed with the aim of reducing procedural times and reducing complications related to the ablative procedure with radiofrequency without losing efficacy. Recent studies conducted with rigour and scientific solidity have demonstrated on the one hand that the results of this technique are not inferior compare with radiofrequency. This study aims to compare data on the safety and efficacy of cryoablation with those obtained from antiarrhythmic drugs through a review of the most recent scientific evidence.

Meta-analysis of pulsed-field ablation versus cryoablation for atrial fibrillation.

The available data on the treatment strategy of pulsed field ablation (PFA) for patients with atrial fibrillation (AF) is limited. This study aims to provide a comparative analysis of the efficacy, safety, and procedural efficiency between PFA and cryoballoon ablation (CBA) for AF. We conducted a comprehensive search of the EMBASE, PubMed, Cochrane Library, and ClinicalTrials.gov databases to identify trials comparing PFA with CBA for AF from their inception until December 2023. The odds ratio (OR) and mean difference (MD), along with a 95% confidence interval (CI), were utilized as measures of treatment effect. The analysis included 15 eligible trials with a total enrollment of 1880 patients. No significant differences were found in recurrent atrial arrhythmia (OR 0.83, 95% CI 0.64, 1.07) or periprocedural complications (OR 0.78, 95% CI 0.46, 1.30) between the two ablation techniques examined in this study. However, the PFA technique demonstrated a significantly shorter procedure time (MD -7.17, 95% CI -13.60, -0.73), but a longer fluoroscopy time (MD 2.53, 95% CI 0.87, 4.19). Similarly, PFA was found to be significantly associated with a decreased incidence of phrenic nerve palsy (OR 0.20, 95% CI 0.07, 0.59), but an increased incidence of cardiac tamponade (OR 4.07, 95% CI 1.15, 14.39). Moreover, there was a significantly higher release of troponin with PFA compared to CBA (MD 470.28, 95% CI 18.89, 921.67), while the increase in S100 protein and heart rate was significantly lower with PFA than with CBA (MD -64.41, 95% CI -105.46, -17.36), (MD -8.76, 95% CI -15.12, -2.40). The utilization of PFA provides a safer, time-saving, and tissue-specific procedure compared to CBA, while maintaining comparable success rates. This has the potential to enhance procedural efficiency and optimize resource utilization in clinical practice. These findings underscore the feasibility and promise of PFA as an alternative technique for PVI in patients with AF.

Reshaping Prognosis: Atrial fibrillation ablation in a case of severe tachycardiomyopathy in a young patient

Abstract Tachycardiomyopathy, characterized by ventricular systolic dysfunction resulting from persistent tachycardia, poses a significant challenge in cardiovascular disease management. This article presents the case of a 31-year-old male patient with dilated cardiomyopathy and recurrent persistent atrial fibrillation, admitted due to heart failure decompensation. Ischemic and inflammatory etiologies for heart failure were ruled out in prior assessments. Despite multiple antiarrhythmic drugs and attempted electrical cardioversion, sinus rhythm was not maintained. Echocardiography confirmed a decline in the already reduced ejection fraction. Atrial fibrillation cryoablation was performed, and procedural specifics are detailed. Subsequent follow-up visits revealed a noteworthy improvement in exercise tolerance and ventricular function. This case underscores the importance of considering tachycardiomyopathy in the differential diagnosis of new-onset or worsening heart failure and highlights the potential for symptom resolution and ventricular function recovery with atrial fibrillation ablation.

Incidence of cryoballoon expansion dislodgement during pulmonary vein isolation-An underappreciated frequent cause of incomplete isolation.

Cryoballoon ablation for atrial fibrillation (AF) requires adequate contact between the pulmonary vein (PV) antrum and cryoballoon. The surge of intraballoon pressure during the initial phase of ablation may change the balloon's shape and compliance, resulting in balloon dislodgement and loss of PV occlusion. Without continuous monitoring, this phenomenon is often undetected but can be associated with incomplete PV isolation (PVI). Primary cryoablation of AF was performed in 15 patients. PV occlusion status pre- and post-freezing were analyzed with intracardiac echocardiography (ICE) and dielectric imaging-based occlusion tool (DIOT) to calculate the incidence of expansion dislodgement of cryoballoon. A total of 105 cryoablation applications were performed on 57 veins, including three common ostiums of left pulmonary veins. In the evaluation of PV occlusion, both modalities reported consistent results in 86.7% of the assessments. Despite complete PV occlusion before ablation, peri-balloon leak after initiation of freezing was detected by ICE in 5/22 (22.7%) applications and by DIOT in 8/25 (32%) applications. Incidence of expansion dislodgement of the cryoballoon was detected in one-fourth to one-third of cryoablation applications depending on the imaging modality used, which was clinically frequent and significant.

Impact of a quality improvement project addressing freezing time and temperature in cryoballoon atrial fibrillation treatment

BackgroundThis study focuses on a quality improvement (QI) project initiated in April 2019, aimed at reducing redo rates in pulmonary vein isolation (PVI) procedures.MethodsThe study included patients undergoing cryoablation for atrial fibrillation (AF) at a Dutch heart center between June 2015 and December 2021. Patients were categorized into pre-QI (June 2015 to April 2019) and post-QI (April 2019 to December 2021) cohorts. The primary metric was the 6-month redo rate, analyzed using descriptive statistics, cumulative sum (CUSUM) chart for trend analysis, and logistic regression for result validation.ResultsOf 2484 patients, 1410 were in the pre-QI cohort and 1074 in the post-QI cohort. Significant differences in median age, left atrium volume, left ventricular ejection fraction, and AF type were observed between the cohorts. The overall 6-month redo rate was 11.2%. Post-QI, redo rates improved gradually, as shown by CUSUM analysis. Logistic regression indicated a reduced risk of redo ablation at 6 months post-QI (OR 0.70, 95% CI 0.54 - 0.91), after adjusting for baseline characteristics.ConclusionRoutine care evaluation can guide the implementation of value-based QI projects, improving outcomes for PVI patients. Factors like freeze duration and temperature were associated with redo rates.

Cryoballoon ablation for atrial fibrillation in patients with heart failure and reduced left ventricular ejection fraction: A systematic review and meta-analysis.

The coexistence of atrial fibrillation (AF) with heart failure (HF) is prevalent, leading to severe complications. This review aimed to investigate the success rate and efficacy of cryoballoon ablation (CBA) by measuring the improvement in the New York Heart Association (NYHA) classification and the effect on the left ventricular systolic function in patients with AF accompanied by heart failure with reduced ejection fraction (HFrEF). Electronic databases search included PubMed, Web of Science, and Scopus in January 2023. Outcomes addressed the following: left ventricular ejection fraction (LVEF) improvement, AF recurrence, NYHA classification improvement, and mortality. STATA 17.0 software was used for data analysis. The effect size for the studies was a standard mean difference (SMD) with a 95% confidence interval (CI) for outcomes. Proportion analysis with 95% CI was used for freedom from early AF and AF after 2 years and all-cause death. We included six studies, including 1699 HF patients with 365 HFrEF patients. The SMD of postoperative LVEF compared to preoperative LVEF in HFrEF was 0.99 ([95% CI: 0.60, 1.39], p = .00), and for NYHA was -1.12 ([95% CI: -1.36, -0.87], p = .00). The analysis results in HFrEF patients for freedom from AF after 1 year was 65% ([95% CI: 0.55, 0.75], and after 2 years was 39% ([95% CI: 0.10, 0.67]). Proportional analysis was conducted for all-cause death, resulting in 3% mortality ([95% CI: -0.01, 0.07]). Cryoablation of AF accompanied by HFrEF appeared safe as it reduced AF recurrence and enhanced clinical outcomes.

Solving difficulties in transseptal sheath crossing: The shoehorn technique.

The shoehorn technique is a simple and safe maneuver that can help to solve difficulties in challenging transseptal sheath crossing for atrial fibrillation cryoablation procedures.

Inflammatory Markers as Predictors of Atrial Fibrillation Recurrence: Exploring the C-Reactive Protein to Albumin Ratio in Cryoablation Patients.

Atrial fibrillation (AF) is a common cardiac rhythm disorder associated with hemodynamic disruptions and thromboembolic events. While antiarrhythmic drugs are often recommended as the initial treatment, catheter ablation has emerged as a viable alternative. However, the recurrence of AF following ablation remains a challenge, and there is growing interest in exploring inflammatory markers as predictors of recurrence. This retrospective, cross-sectional analysis included 249 patients who underwent cryoablation for paroxysmal AF. The relationship between the 'C-reactive protein (CRP) to albumin ratio (CAR)' and AF recurrence was examined. Two hundred and forty-nine patients with paroxysmal non-valvular atrial fibrillation were included. They were divided into two groups: those without recurrence (Group 1) and those with recurrence (Group 2). Significant differences were observed in age (57.2 ± 9.9 vs. 62.5 ± 8.4, p = 0.001) and left atrial size (4.0 ± 0.5 vs. 4.2 ± 0.7, p = 0.001) between the two groups. In blood parameters, significant differences were found in CRP (5.2 ± 1.3 vs. 9.4 ± 2.8, p < 0.001) and neutrophil counts (5.1 ± 2.2 vs. 6.7 ± 3.6, p = 0.001). In univariate regression analysis, age (OR: 1.058, CI: 1.024-1.093, p = 0.001), WBC count (OR: 1.201, CI: 1.092-1.322, p < 0.001), neutrophil count (OR: 1.239, CI: 1.114-1.378, p = 0.001), CAR (OR: 1.409, CI: 1.183-1.678, p < 0.001), and left atrial diameter (OR: 0.968, CI: 0.948-0.989, p = 0.002) showed significant associations with AF recurrence. Inflammation plays a crucial role in the initiation and progression of AF. This study demonstrated that along with age, the CAR can serve as an independent predictor of AF recurrence following cryoablation.

Single-shot technique of cryoablation for atrial fibrillation has comparable effective and safety outcomes compared to standard technique: insights from multiple clinical studies.

Although there are many freezing protocols available, the optimal freezing dose is still not determined. We aimed to evaluate the effectiveness and safety of different freeze strategies of CBA in the treatment of AF. PubMed, Cochrane Library, Web of Science, and Embase were searched up to 1st December 2022. Studies comparing the outcomes between single-shot technique and standard technique of cryoablation were included. Subgroup analysis identified potential determinants for single-shot technique procedure. Our search resulted in 3407 records after deduplication. A total of 17 qualified studies met our inclusion criteria. Compared with standard technique, single-shot technique of cryoablation has a comparable rate of freedom from AF/AT(RR 1.00; P = 0.968), a trend for lower rate of procedure complications (RR 0.80; P = 0.069), a lower rate in transient phrenic paralysis (t-PNP) (RR 0.67; P = 0.038), a similar rate in persistent phrenic paralysis (per-PNP) (RR 1.15; P = 0.645), as well as a comparable procedure parameters. Importantly, potentially significant treatment covariable interactions in procedure complications were found in freeze strategy subgroup, male proportion subgroup and age subgroup, including single-shot freeze (RR 1.02; P = 0.915) and TTI-guided (RR 0.63; P = 0.007) with interaction P = 0.051, high male proportion (RR 0.54; P = 0.005) and a low male proportion (RR 0.94; P = 0.759) with interaction P = 0.074, as well as age ≥ 65 (RR0.91; P = 0.642) and age <65 (RR 0.54; P = 0.006),interaction P = 0.090. Meanwhile, only one significant treatment covariable interactions in procedure complications was found in the hypertension subgroup, including HT > 60% (RR 0.89; P = 0.549) and HT ≤ 60% (RR 0. 46; P < 0.01) with interaction P = 0.043. Our study suggested that single-shot technique of cryoablation has comparable effective and safety outcomes for AF ablation compared to standard technique.

Robotic-assisted mitral valve surgery without aortic cross-clamping: a safe and feasible technique.

The primary objective of this study was to evaluate the safety and feasibility of robotic-assisted mitral valve surgery without aortic cross-clamping. From January 2010 to September 2022, 28 patients underwent robotic-assisted mitral valve surgery without aortic cross-clamping in our center using DaVinci Robotic Systems. Clinical data during the perioperative period and early outcomes of the patients were recorded. Most patients were in New York Heart Association (NYHA) class II and III. Mean age and EuroScore II of the patients were 71.5 ± 13.5 and 8.4 ± 3.7 respectively. The patients underwent either mitral valve replacement (n = 16, 57.1%) or mitral valve repair (n = 12, 42.9%). Concomitant procedures were performed including tricuspid valve repair, tricuspid valve replacement, PFO closure, left atrial appendage ligation, left atrial appendage thrombectomy and cryoablation for atrial fibrillation. Mean CPB times were 140.9 ± 44.6 and mean fibrillatory arrest duration was 76.6 ± 18.4. Mean duration of ICU stay was 32.5 ± 28.8 h and mean duration of hospital stay 9.8 ± 8.3 days. One patient (3.6%) underwent revision due to bleeding. New onset renal failure was observed in one (3.6%) patient and postoperative stroke in one (3.6%) patient. Postoperative early mortality was observed in two (7.1%) patients. Robotic-assisted mitral valve surgery without cross-clamping is a safe and feasible technique in high-risk patients undergoing redo mitral surgery with severe adhesions as well as in primary mitral valve cases that are complicated with ascending aortic calcification.

Pulsed-field ablation for redo procedures after failed radiofrequency or cryo ablation for atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulsed-field ablation (PFA) has recently been introduced for pulmonary vein isolation (PVI). It might also be of potential value for redo procedures after failed radiofrequency or cryo ablation for atrial fibrillation (AF). Purpose To describe our initial experience using a multipolar PFA catheter for redo procedures after failed AF ablation. Methods Consecutive patients undergoing a redo procedure for recurrent atrial arrhythmias at our institution using a multipolar PFA catheter from Mai 2021 until October 2022 were included. A 3D electro-anatomical bipolar voltage map was generated to identify pulmonary vein (PV) reconnection, quantify the level of isolation (antral vs. ostial isolation), and characterize the extent of extra-PV low-voltage tissue. In case of PV reconnection, re-isolation was performed using PFA, with at least four applications in both basket and flower configuration. In case of only ostial PV isolation, additional PFA applications in flower configuration were delivered to widen the isolation to a more antral level. If all veins were already isolated on an antral level and/or if low-voltage areas were found on the posterior wall, a posterior wall ablation was added with the same PFA device at the discretion of the operator. Results We identified 170 patients (mean age: 64 ±11years, 45 (27%) women), undergoing a redo procedure using PFA. The median number of previous ablations was 1 (range 1-6), the most recent ablation was performed using radiofrequency in 122 (72%), cryo in 42 (25%), and surgery in 5 (3%) patients. In 104 (61%) patients, at least one reconnected PV was found. In total, 244 of 680 PV (36%) showed reconnection. In addition to PV reisolation, additional antral applications were delivered in 205 of 436 still isolated veins (47%). Posterior wall ablation was added in 112 (66%) patients (43% in paroxysmal AF, 78% in persistent AF, Figure). Median procedure duration was 101 minutes (IQR 80-137). There was no cardiac tamponade, no stroke, and no esophageal fistula observed in this cohort. Conclusion For patients with recurrence after catheter ablation of atrial fibrillation, re-ablation using PFA is feasible and safe. Most common ablation targets were the pulmonary veins and the posterior wall. Whether the complementary effect of a different technology improves outcome needs further investigation.

3D imaging assistance impact on atrial fibrillation cryoablation efficiency, a method validation study

Abstract Funding Acknowledgements Type of funding sources: Other. Main funding source(s): CGRA: CARD; CGRB: 31’297 Background Pulmonary vein isolation (PVI) by cryoballoon ablation is a well-known therapy for the treatment of atrial fibrillation (AF). Current 3D-navigation technologies usually used with RF ablation allow for a drastic reduction of intra-procedural X-ray exposure and imaging aided/guided methods allow for better anatomical characterization improving acute and long-term procedural results. 3D imaging fusion on real-time fluoroscopy is a well-known technology but the incremental value of 3D imaging fusion as a guiding tool on AF cryoballoon ablation therapy has not been studied yet. Purpose To increase procedural efficiency by integration of 3D imaging guidance in conventional cryoballoon PVI. Methods Using semi-automatic segmentation (Alphenix, Canon Medical Systems Corporation) obtained from pre-procedural cardiac computed tomography (CT); two anatomic volumes were fused on the real-time fluoroscopy display: left atrium (LA), including pulmonary veins (PV) and spine with proximal rib section (most radio-opaque body part in the thoracic area). The merging was performed by 3D registration of the bone segment with fluoroscopic acquisitions in three standard positions (AP, LAO, RAO), acquired at the beginning of the procedure. To standardize treatment workflow, the study was restricted to patients with paroxysmal atrial fibrillation. Results Twenty patients were included in the study: 10 in the control group (conventional fluoroscopy based cryoballoon ablation), and 10 in the 3D assisted group. Mean age was 59±15 SD years for the conventional group and 61.3±15.1 SD years for the 3D group with an 80% male population, in both groups. Acute PVI was achieved in all 20 patients. A decrease of both procedure time 86.8±16.1 SD in the control group Vs. 78.4±15.32 SD in the 3D group, and left sided dwelling time 69.7±14.31 SD in the control group Vs. 63.9±13.96 SD in the 3D group, although this trend did not reach statistical significance, while radiation time and cryo application time remained similar. Conclusions 3D imaging integration is feasible and safe and allows for an exact PV anatomy depiction on fluoroscopy. The assistance workflow might help increase AF cryoablation efficiency and safety (lower left sided dwelling time). Further research is needed to evaluate the incremental value of 3D imaging to assist fluoroscopy-based cryoballoon ablation. This could also impact long-term results since 3D Imaging assistance could reduce the likeability of missing intermediate PVs during AF ablation procedures.

Cryoablation for atrial fibrillation combined with closure of left atrial appendage.

Cryoablation for atrial fibrillation combined with closure of left atrial appendage.

Impact of first-line cryoablation for atrial fibrillation on healthcare utilization, arrhythmia disease burden and efficacy outcomes: real-world evidence from the Cryo Global Registry.

Cryoballoon ablation (CBA) is an effective first-line treatment for symptomatic atrial fibrillation (AF), as recently demonstrated by three randomized trials. This sub-analysis of the Cryo Global Registry aims to examine current clinical practices of first-line CBA. AF patients treated with first-line CBA were compared to CBA in antiarrhythmic drug (AAD)-refractory patients at 12months. Efficacy was examined using time-to-first atrial arrhythmia recurrence following a 90-day blanking period. Healthcare utilization was evaluated by repeat ablations and hospitalizations. Disease burden was examined by assessing quality of life (QOL) and patients' reporting of symptoms. Of 1394 patients, 433 (31.1%) were treated with first-line CBA, which was more frequent in high-volume centers. Serious procedure-related adverse event rates were similar. Efficacy at 12months was higher in the first-line group (87.8 vs. 81.6%, HRunadj 0.64 (95% CI 0.47-0.88); p < 0.01) regardless of the centers' CBA experience; when controlling for baseline characteristics, the difference was not significant (HRadj 0.87 (95% CI 0.56-1.37); p = 0.55). No difference was observed in repeat ablations and hospitalizations between cohorts. First-line patients experienced a larger mean reduction in symptoms and were prescribed AADs at a lower rate at 12-month follow-up (9.7 vs. 29.9%). QOL improved in both cohorts from baseline to 12months with no significant difference between groups (p = 0.29). In this global real-world experience, first-line CBA in patients with symptomatic AF is effective, with a larger symptom reduction compared with CBA after AAD failure and without a difference in healthcare utilization at mid-term follow-up. https://clinicaltrials.gov/ct2/show/NCT02752737.

Advantage of POLARx over ARCTIC FRONT ADVANCE PRO during pulmonary vein isolation for paroxysmal atrial fibrillation

Abstract Introduction The electrical pulmonary vein (PV) isolation has been established as a curative therapy for paroxysmal atrial fibrillation (AF). Arctic Front™cryoballoon has been used worldwide for AF cryoablation. Recently, a new cryoballoon, POLARxTM CRYOABLATION system have been introduced, of which material of the balloon is softer and the N2O gas flow rate is higher. Purpose The aim was to investigate the procedural parameter and efficacy of POLARx comparing with Arctic Front. Methods This retrospective single center study included 101 consecutive patients who underwent paroxysmal AF ablation using cryoballoon at Keio University hospital from April 2021 to March 2022. The procedural data including the cryoballoon temperature and the number and duration of cryoablation were compared between POLARx (POLARx group) and ARCTIC FRONT ADVANCE PRO (AFA group). After the cryoablation, we added the radiofrequency application in order to maximize the isolated area when the voltage was remained inside PV (Figure 1). The necessities of the additional radiofrequency applications were also compared. Results In the present study, 64 patients in AFA group and 37 patients in POLARx group were analyzed. POLARx group included younger population and less females (62.8±9.9 vs 67.5±9.4 year of age, P=0.02; 13.5 vs 32.8%, P=0.04). There was no significant difference in comorbidities and examination data such as left atrium diameter or brain natriuretic peptide level. The minimal cryoballoon temperatures reached in POLARx group were lower than AFA group (−59.3±6.2 vs −47.7±7.5°C, P&amp;lt;0.01). No difference was found in the total number and duration of cryoablation and the time to isolate PV (6.1±2.1 vs 5.9±1.6, P=0.69; 790.2±256.1 vs 776.1±235.0 sec, P=0.69; 41.8±21.3 vs 47.1±29.6 sec, P=0.44, respectively). With regard to individual PVs, the total number and duration were tended to be larger at right superior PV in POLARx group (1.9±1.1 vs 1.4±0.7, P=0.01; 231.8±123.8 vs 193.2±83.0 sec, P=0.07), while there was no significant difference at the other PVs. The rate of successful PV isolation by a single cryo-application was not different between AFA and POLARx group (54.3 vs 61.4%, P=0.17). The additional radiofrequency applications were more frequent in AFA group (14.8 vs. 4.9%, P=0.003). There was a significant difference at right inferior PV (32.8 vs 8.1%, P=0.01), while not at left superior PV, left inferior PV and right superior PV (9.4 vs 2.9%, P=0.42; 9.4 vs 5.7%, P=0.71; 7.8 vs 2.7%, P=0.41). Phrenic nerve injury was occurred 1 case in both group and esophageal ulcer was occurred in 1 case in AFA group. No other complication including cardiac tamponade was occurred. Conclusion The total number and duration of cryoablation were not significantly different between AFA and POLARx group, except for right superior PV. There was an advantage in largely isolating right inferior PV in POLARx group comparing with AFA group. Funding Acknowledgement Type of funding sources: None.