The impact of early cryoballoon ablation on clinical outcome in patients with atrial fibrillation: From the Korean cryoballoon ablation registry.

INTRODUCTION: Influence of early atrial fibrillation (AF) ablation, particularly cryoballoon ablation (CBA), on clinical outcome during long-term follow-up has not been clarified. The objective was to determine whether an early CBA (diagnosis-to-ablation of ≤6 months) strategy could affect freedom from AF recurrence after index CBA. METHODS: The study included 2605 patients from Korean CBA registry data with follow-up >12 months after de novo CBA. The primary outcome was recurrence of atrial tachyarrhythmias (ATs) of ≥30-s after a 3-month blanking period. RESULTS: Compared to patients in early CBA group, patients in late CBA group had higher prevalence of diabetes, congestive heart failure, and chronic kidney disease, and higher mean CHA2 DS2 -VAS score. During mean follow-up of >21 months, ATs recurrence was detected in 839 (32.2%) patients. The early CBA group showed a significantly lower 2-year recurrence rate of ATs than the late CBA group (26.1% vs. 31.7%, p = 0.043). In subgroup analysis, the early CBA group showed significantly higher 1-year and 2-year freedom from ATs recurrence than the late CBA group only in paroxysmal atrial fibrillation (PAF) patients in overall and propensity score matched cohorts. Multivariate analysis showed that early CBA was an independent factor for preventing ATs recurrence in PAF (hazard ratio: 0.637; 95% confidence intervals: 0.412-0.984). CONCLUSION: Early CBA strategy, resulting in significantly lower ATs recurrence during 2-year follow-up after index CBA, might be considered as an initial rhythm control therapy in patients with paroxysmal AF.

One-year outcomes of pulmonary vein isolation with a novel cryoballoon: Primary results of the FROZEN AF trial.

INTRODUCTION: Cryoablation therapy for pulmonary vein isolation (PVI) to treat paroxysmal atrial fibrillation (PAF) is well established. A novel 28 mm cryoballoon system designed to operate under low pressure to safely reach a lower nadir temperature and maintain constant balloon size during cooling has not been prospectively studied in a large patient population for safety and efficacy. The FROZEN AF (NCT04133168) trial was an international multicenter, open-label, prospective, single-arm study on the safety and performance of a novel cryoballoon system for treatment of PAF. METHODS AND RESULTS: The study enrolled patients at 44 sites in 10 countries across North America, Europe, and Asia. Subjects were indicated for PVI treatment of PAF and had failed or were intolerant of one or more antiarrhythmic drugs. Procedural outcomes were defined based on the 2017 HRS consensus statement. Follow-up was performed at 7 days, 3, 6, and 12 months. Data are reported as mean ± SD or median (IQR). PVI was performed with a 28 mm cryoballoon in 325 drug refractory PAF patients. Complete PVI was achieved in 95.7% of patients. In cryoablation lesions longer than 60 s, 60.1% of PV isolations required only a single cryoballoon application. Procedure related complications included: phrenic nerve palsy [temporary 4 (1.2%), persistent 0 (0.0%)], cardiac tamponade/perforation 2 (0.6%), and air embolism 1 (0.3%). Freedom from documented atrial arrhythmia recurrence at 12 months was 79.9% (AF 82.7%, AFL 96.5%, AT 98.1%), antiarrhythmic drugs (AAD) were continued or re-initiated in 26.8% of patients after the 3-month blanking period. Additionally, an extension arm enrolled 50 pts for treatment with 28/31 mm variable size cryoballoon. A single temporary PNP occurred in this group, which resolved before discharge. Freedom from documented recurrence at 12 months in these pts was 82.0%. CONCLUSIONS: This novel cryoballoon may facilitate PVI to treat PAF, providing more options to address the variety of anatomies present in patients with PAF. This cryoballoon system proved to be safe and effective for treatment of patients with drug refractory or drug intolerant PAF.

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.

INTRODUCTION: 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). METHODS AND RESULTS: 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). CONCLUSION: 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.

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

INTRODUCTION: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Pulmonary vein reconnection and repeat ablation characteristics following cryoballoon-compared to radiofrequency-based pulmonary vein isolation.

BACKGROUND: Despite advances in efficacy and safety of pulmonary vein isolation (PVI), atrial fibrillation (AF) recurrence after PVI remains common. PV-reconnection is the main finding during repeat PVI procedures performed to treat recurrent AF. OBJECTIVE: To analyze pulmonary vein (PV) reconnection patterns during repeat ablation procedures in a large cohort of consecutive patients undergoing radio frequency or cryoballoon-based PVI. METHODS: Retrospective analysis of PV-reconnection patterns and analysis of re-ablation strategies in consecutive index RF- and CB-based PVI and their respective re-ablation procedures during concomitant usage of both energy sources at a single high-volume center in Germany. RESULTS: A total of 610 first (06/2015-10/2022) and 133 s (01/2016-11/2022) repeat ablation procedures after 363 (60%) RF- and 247 (40%) CB-based index PVIs between 01/2015 and 12/2021 were analyzed. PV-reconnection was found in 509/610 (83%) patients at first and 74/133 (56%) patients at second repeat procedure. 465 of 968 (48%) initially via CB isolated PVs were reconnected at first re-ablation but 796 of 1422 initially RF-isolated PV (56%) were reconnected (OR: 0.73 [95% CI: 0.62-0.86]; p < .001). This was driven by fewer reconnections of the left PVs (LSPV: OR: 0.60 [95% CI: 0.42-0.86]; p = .005 and LSPV: 0.67 [0.47-0.95]; p = .026). PV-reconnection was more likely after longer, RF-based index PVI and in older females. Repeat procedures were shorter after CB-compared to after RF-PVI. CONCLUSIONS: Reconnection remains the most common reason for repeat AF ablation procedures after PVI. Our data suggest to preferentially use of the cryoballoon during index PVI, especially in older women.

Prospective multicenter trial of the cryoballoon ablation system for superficial esophageal squamous cell carcinoma on the post-endoscopic resection scar. A CRYO-SCAR study (EPOC1902).

BACKGROUND AND AIMS: Endoscopic resection (ER) is a minimally invasive treatment for superficial esophageal squamous cell carcinoma (SESCC). Post-ER scars complicate en bloc resection, even with advanced techniques, such as endoscopic submucosal dissection. The cryoballoon ablation system (CBAS) effectively manages Barrett's esophagus but has limited evidence in SESCC treatment, particularly on post-ER scars. This study aimed to evaluate the efficacy and safety of the CBAS for treating SESCC on post-ER scars. METHODS: This prospective study was conducted at two tertiary referral centers in Japan in patients endoscopically diagnosed with T1a SESCC on the post-ER scar. Focal CBAS was used for cryoablation, with specific criteria for lesion selection and treatment method. The primary endpoint was local complete response (L-CR) rate of the primary lesion 48 weeks after the first cryoablation as evaluated by an independent central evaluation committee. RESULTS: From October 2020 to October 2021, 15 patients with 17 lesions underwent cryoablation, with two requiring repeat cryoablation. The L-CR rate for primary and all lesions evaluated by the central evaluation committee was 100%. The endoscopist's evaluation was consistent with these results. The median procedure time was 9 min. Eight patients experienced no pain, and the highest pain score reported on a numeric 1-10 rating scale was 3. The technical success rate was 94.7% (18/19). Throughout the median follow-up period of 14.3 months, recurrences, deaths, or severe treatment-related adverse events were not reported. CONCLUSIONS: CBAS is a potentially safe and effective approach for SESCC on post-ER scars and represents an encouraging alternative to traditional endoscopic treatments.

Long-term efficacy and safety of cryoballoon ablation of atrial fibrillation: A systematic review and meta-analysis.

BACKGROUND: This meta-analysis evaluated long-term efficacy and safety of cryoballoon ablation (CB) of atrial fibrillation (AF). METHODS: PubMed, Cochrane Library, and Web of Science were searched until July 31, 2023, for published works investigating efficacy and safety of CB of AF in which mean/median follow-up time was not less than 36 months. Safety was assessed by adverse events. Efficacy was assessed by AF recurrence, defined as any atrial arrhythmias lasting more than 30 s. RESULTS: A total of 19 clinical studies were included. After an average of 58.1 months of follow-up, the overall AF recurrence rate was about 37%. The predictors of recurrence were duration of AF (HR 1.00; 95% CI [1.00 ∼ 1.01]), early recurrence of atrial fibrillation (HR 3.96; 95%CI [1.12 ∼ 14.02]), left atrial diameter (HR 1.04; 95%CI [1.02 ∼ 1.06]), and persistent AF (HR1.47; 95% CI [1.19 ∼ 1.82]). In terms of safety, the incidence of transient phrenic paralysis (PNP) was the highest, about 3%; followed by vascular complications (about 2%); pseudoaneurysm, permanent PNP, and all-cause death was (about 1%); and pericardial effusion and stroke / TIA was very low. CONCLUSION: CB is associated with low rates of severe complications and reasonable success rates.

Cryoballoon pulmonary vein isolation versus radiofrequency ablation of the pulmonary veins and left atrial posterior wall: Patient-reported outcomes.

BACKGROUND: Data are lacking on patient-reported outcomes (PRO) following cryoballoon ablation (CBA) versus radiofrequency ablation (RFA). We sought to evaluate QoL and clinical outcomes of cryoballoon pulmonary vein isolation only (CRYO-PVI-ONLY) versus RFA with PVI and posterior wall isolation (RF-PVI+PWI) in a large prospective PRO registry. METHODS: Patients who underwent AF ablation (2013-2016) at our institution were enrolled in an automated, prospectively maintained PRO registry. CRYO-PVI-ONLY patients were matched (1:1) with RF-PVI+PWI patients based on age, gender, and type of AF (paroxysmal vs. persistent). QoL and clinical outcomes were assessed using PRO surveys at baseline and at 1-year. The atrial fibrillation symptom severity scale (AFSSS) was the measure for QoL. Additionally, we assessed patient-reported clinical improvement, arrhythmia recurrence, and AF burden (as indicated by AF frequency and duration scores). RESULTS: A total of 296 patients were included (148 in each group, 72% paroxysmal). By PRO, a significant improvement in QoL was observed in the overall study population and was comparable between CRYO-PVI-ONLY and RF-PVI+PWI (baseline median AFSSS of 11.5 and 11; reduced to 2 and 4 at 1 year, respectively; p = 0.44). Similarly, the proportion of patients who reported improvement in their overall QoL and AF related symptoms was high and similar between the study groups [92% (CRYO-PVI-ONLY) vs. 92.8% (RF-PVI+PWI); p = 0.88]. Arrhythmia recurrence was significantly more common in the CRYO-PVI-ONLY group (39.7%) compared to RF-PVI+PWI (27.7 %); p = 0.03. Comparable results were observed in paroxysmal and persistent AF. CONCLUSION: CRYO-PVI-ONLY and RF-PVI+PWI resulted in comparable improvements in patient reported outcomes including QoL and AF burden; with RF-PVI+PWI being more effective at reducing recurrences.

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

PURPOSE: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Meta-analysis of high-power short-duration versus cryoballoon ablation for atrial fibrillation.

BACKGROUND: The existing literature regarding the treatment strategy for high-power short-duration (HPSD) ablation in patients diagnosed with atrial fibrillation (AF) is currently insufficient. The objective of this study is to perform a comparative analysis evaluating the effectiveness, safety, and procedural efficiency of HPSD versus cryoballoon ablation (CBA) for AF. METHODS: A comprehensive search was conducted in PubMed, EMBASE, Cochrane Library, Scopus, Web of Science, and ClinicalTrials.gov databases to identify trials comparing HPSD with CBA for AF from their inception until December 25, 2023. Treatment effect measures were expressed as odds ratio (OR), mean difference (MD), accompanied by a 95% confidence interval (CI). RESULTS: The analysis comprised six eligible trials involving a total enrollment of 2481 patients. No statistically significant disparities were observed in recurrent atrial arrhythmia (OR 0.90; 95% CI, 0.71-1.16) or total complications (OR 0.65; 95% CI, 0.38-1.12) between the two ablation techniques examined in this study. However, HPSD technique exhibited a significantly prolonged procedure time (MD 27.42; 95% CI, 19.03 to 35.81). Conversely, no significant differences were observed between the two modalities in terms of total fluoroscopy duration (MD -4.37; 95% CI -10.70 to 1.96) and ablation time (MD 7.95; 95% CI -3.97 to 19.88). Furthermore, HPSD demonstrated significantly higher odds of extrapulmonary vein (PV) trigger ablation compared to CBA (OR 18.86; 95% CI, 5.12-69.49). The subgroup analyses revealed that CBA continued to exhibit superior procedure time (except for the paroxysmal AF subgroup: [MD 29.52; 95% CI -4.25 to 63.60]), while no significant differences in safety and efficacy (except for the HPSD ≥ 70 W subgroup: [OR 0.44, 95% CI 0.20-0.97]) outcomes were still observed. CONCLUSION: Among patients undergoing ablation therapy for AF, both HPSD and CBA demonstrate comparable efficacy and safety profiles; however, HPSD is associated with longer procedural time and higher rates of extra-PV trigger ablation.

The efficacy and safety of cryoballoon atrial fibrillation ablation in patients with heart failure: A systematic review and meta-analysis.

INTRODUCTION: While atrial fibrillation (AF) ablation has proven beneficial for heart failure (HF) patients, most reports were performed with radiofrequency ablation. We aimed to evaluate the efficacy and safety of cryoballoon AF ablation in patients with HFrEF. METHOD: We comprehensively searched the databases of MEDLINE, EMBASE, and Cochrane database from inception to December 2022. Studies that reported the outcomes of freedom from atrial arrhythmia, complications, NYHA functional class (NYHA FC), and left ventricular ejection fraction (LVEF) after Cryoballoon AF ablation in HF patients were included. Data from each study were combined with a random-effects model. RESULT: A total of 9 studies observational studies with 1414 HF patients were included. Five studies had only HF with reduced ejection fraction (HFrEF), 1 study with HF with preserved ejection fraction (HFpEF), and others with mixed HF types. Freedom from AA in HFrEF at 12 months was 64% (95% CI 56-71%, I2 58%). There was a significant improvement of LVEF in these patients with a standard mean difference of 13% (95% CI 8.6-17.5%, I2 99% P < 0.001. The complication rate in HFrEF group was 6% (95% CI 4-10%, I2 0%). The risk of recurrence of atrial arrhythmia was not significantly different between HF and no HF patients (RR 1.34, 95% CI 0.8-2.23, I2 76%). CONCLUSION: Cryoballoon AF ablation is effective in HFrEF patients comparable to radiofrequency ablation. The complication rate was low.

Pulsed field versus cryoballoon ablation for atrial fibrillation: a real-world observational study on procedural outcomes and efficacy.

INTRODUCTION: Atrial fibrillation often necessitates catheter ablation when antiarrhythmic drug therapy fails. Single-shot technologies using thermal energy, such as cryoballoon ablation, are commonly used, but pulsed field ablation (PFA), an innovative non-thermal ablation technique, is a potential alternative. This retrospective observational study aimed to compare the safety and efficacy of cryoballoon ablation and PFA in patients undergoing their first pulmonary vein isolation (PVI) procedure for atrial fibrillation treatment. METHODS: We utilised real-world data from patients who underwent PVI using cryoballoon ablation or PFA. The primary outcome encompassed procedural complications, including phrenic nerve palsy, cardiac tamponade, thromboembolic complications, bleeding complications and mortality. Secondary outcomes were procedural characteristics including procedure duration, length of hospital admission, and re-do ablation rates within 6 months. RESULTS: A total of 1714 procedures were analysed: 1241 in the cryoballoon group and 473 in the PFA group. Gender distribution (p = 0.03) and estimated glomerular filtration rate (p = 0.01) differed significantly. With regard to the primary outcome, the cryoballoon group demonstrated a higher incidence of phrenic nerve palsy compared with the PFA group (15 vs 0; p = 0.02). The procedure duration was shorter in the PFA group, even after adjusting for baseline characteristics (95.0 vs 74.0 min; p < 0.001). After adjustment for baseline characteristics, admission duration differed between the groups as well (p = 0.04). CONCLUSION: The study results supported the safety and efficacy of PFA over cryoballoon ablation for PVI, highlighting advantages such as shorter procedure duration and absence of phrenic nerve palsy.

Elevated fibrosis burden as assessed by MRI predicts cryoballoon ablation failure.

INTRODUCTION: Late-gadolinium enhancement magnetic resonance (LGE-MRI) imaging is increasingly used in management of atrial fibrillation (AFib) patients. Here, we assess the usefulness of LGE-MRI-based fibrosis quantification to predict arrhythmia recurrence in patients undergoing cryoballoon ablation. Our secondary goal was to compare two widely used fibrosis quantification methods. METHODS: In 102 AF patients undergoing LGE-MRI and cryoballoon ablation (mean age 62 years; 64% male; 59% paroxysmal AFib), atrial fibrosis was quantified using the pixel intensity histogram (PIH) and image intensity ratio (IIR) methods. PIH segmentations were completed by a third-party provider as part of the standard of care at our hospital; Image intensity ratio (IIR) segmentations of the same scans were carried out in our lab using a commercially available software package. Fibrosis burdens and spatial distributions for the two methods were compared. Patients were followed prospectively for recurrent arrhythmia following ablation. RESULTS: Average PIH fibrosis was 15.6 ± 5.8% of the left atrial (LA) volume. Depending on threshold (IIRthr ), the average IIR fibrosis (% of LA wall surface area) ranged from 5.0 ± 7.2% (IIRthr = 1.2) to 37.4 ± 10.9% (IIRthr = 0.97). An IIRthr of 1.03 demonstrated the greatest agreement between the methods, but spatial overlap of fibrotic areas delineated by the two methods was modest (Sorenson Dice coefficient: 0.49). Fourty-two patients (41.2%) had recurrent arrhythmia. PIH fibrosis successfully predicted recurrence (HR 1.07; p = .02) over a follow-up period of 362 ± 149 days; regardless of IIRthr , IIR fibrosis did not predict recurrence. CONCLUSIONS: PIH-based volumetric assessment of atrial fibrosis was modestly predictive of arrhythmia recurrence following cryoballoon ablation in this cohort. IIR-based fibrosis was not predictive of recurrence for any of the IIRthr values tested, and the overlap in designated areas of fibrosis between the PIH and IIR methods was modest. Caution must therefore be exercised when interpreting LA fibrosis from LGE-MRI, since the values and spatial pattern are methodology-dependent.

Impact of intracardiac echocardiography usage on the safety of cryoballoon atrial fibrillation ablation: Subanalysis of the prospective FREEZE cluster cohort study.

INTRODUCTION: Cryoballoon ablation (CBA) aiming at pulmonary vein isolation (PVI) became a standardized atrial fibrillation (AF) ablation procedure. Life-threatening complications like cardiac tamponade exist. Intracardiac echocardiography (ICE) usage is associated with superior safety in radiofrequency ablation. It is unclear if ICE has an impact on safety of CBA. METHODS: The FREEZE Cohort (NCT01360008) subanalysis included patients undergoing "PVI only" CBA. Patients with intraprocedural transesophageal echocardiography were excluded. Group A comprises conventional, group B ICE-guided CBA. Periprocedural results were compared. RESULTS: From 2011 to 2016, a total of 4189 patients were enrolled, and 1906 (45.5%) were included in this subanalysis, split up in two groups (A: 1066 [55.9%], B: 840 [44.1%]). Group A was younger (60.6 ± 10.8 vs. 62.4 ± 10.5 years, p < .001), with smaller left atria (41 vs. 43 mm, p < .001), and less persistent AF (23.1 vs. 38.1%, p < .001). Procedure, left atrial, and fluoroscopy times were shorter in group A as compared to group B. Dose area product was significantly higher in group A (2911 vs. 2072 cGyxcm2 , p < .001). In-hospital major adverse cerebrovascular and cardiac event rates including two deaths in group A were not different between groups (0.5% vs. 0.1%, p = .18). The rate of total procedural (10.4% vs. 5.1%, p < .001) and major complications (3.2% vs. 1.3%, p < .001) was significantly higher in group A. Cardiac tamponade occurred significantly more frequently in group A (8 [0.8%] vs. 1 [0.1%], p = .046). Independent predictors for major complications were female sex (odds ratio [OR] 2.03, p = .03) and non-ICE usage (OR 2.38, p = .02). No differences were observed for persistent phrenic nerve palsy, nor for groin complications. CONCLUSION: CBA was significantly safer and required less radiation if ICE was used, although the procedures were more complex. The risk of groin complications was not increased with ICE usage. Non-ICE usage was the only modifiable independent predictor of major complications.

Comparison of pulsed field ablation and cryoballoon ablation for pulmonary vein isolation.

INTRODUCTION: Pulmonary vein isolation (PVI) remains the cornerstone in the treatment of atrial fibrillation (AF). PVI using cryoballoon (CB) technology has emerged as a standard procedure in many centers. Recently, pulsed field ablation (PFA) has been introduced and used to achieve PVI. First data show high acute and favorable long-term outcomes. So far, data comparing these new "single shot" devices are sparse. We sought to compare procedural and outcome data for first time PFA users versus CB in patients undergoing de novo PVI. Furthermore, potentially postprocedural discomfort and affection of autonomic ganglia were assessed. METHODS AND RESULTS: A retrospective analysis and comparison of all de novo PVIs with PFA and CB was performed. Furthermore, PFA PVI learning curve was evaluated. During follow-up, repeat outpatient visits and Holter electrocardiogram were performed to analyze arrhythmia-free survival. Discomfort analysis was obtained by prescribed analgesic medication within first 48 h after PVI. Potential changes in heart rate (HR) between baseline and at 3-month follow-up were evaluated. A total of 108 patients (54 PFA and 54 CB; PFA; 33 (30%) female) with paroxysmal and persistent AF were analyzed. Type of AF was comparable (Patients suffering from PAF: PFA: 16 (30%), CB: 17 (31%), p = 1.0). In 107 (99%) patients, successful PVI was achieved. Transient phrenic palsy omitted complete PVI in one CB patient. A trend for a shorter overall procedure duration was observed in the PFA group (PFA: 64.5 ± 17.5 min; CB: 73.0 ± 24.8 min; p = 0.07). Excluding LA mapping time (first 14 cases), procedure time was significantly shorter using PFA (PFA: 58.0 ± 12.5 min, CB: 73.0 ± 24.8 min, p = 0.0001). Fluoroscopy time was significantly longer for PFA (PFA: 15.3 ± 4.7 min, CB: 12.3 ± 5.3 min; p = 0.001), but significantly less contrast medium was used (PFA: 12 ± 6 mL; CB: 51 ± 29 mL, p < 0.0001). Subgroup analysis of the PFA group revealed a significant shortening of procedure duration over time (first tertile: 72.7 ± 13.5 min, second tertile: 67.3 ± 21.7 min, third tertile: 53.4 ± 9.8 min, first vs. third tertile p < 0.0001). Two cardiac tamponades occurred in the PFA group (p = 0.495), of which one was most likely related to complex transseptal puncture. In the first 48 h after PVI, the number of prescribed analgesics due to postprocedural pain was equal between both groups (PFA: 7 (13%) patients, CB: 10 (19%) patients, p = 0.598). After a FU of 273 ± 129 days, 35 of 47 patients (74%) after PFA and 36 of 50 patients (72%) after CB PVI were free of any atrial arrhythmia (HR: 0.98, p = 0.88). Only in the PFA group, a significant increase in HR 3 months after PVI was observed (pre-PVI: 61 ± 8 beats/min, post-PVI: 65 ± 9 beats/min, p = 0.008). CONCLUSION: The new PFA technology is equally effective and safe as compared to CB for complete PVI with potentially shorter procedure time and significantly less contrast medium. However, AF recurrence rates after PFA PVI seem to be comparable to CB PVI.

Sex-based differences in safety and efficacy of catheter ablation for atrial fibrillation.

BACKGROUND: Studies have identified significant sex-based differences and disparities in the clinical presentation and treatment of atrial fibrillation (AF). Studies have shown women are less likely to be referred for catheter ablation, are older at the time of ablation, and are more likely to have recurrence after ablation. However, in most studies investigating AF ablation outcomes, the female cohorts were relatively small. The impact of sex on the outcome and safety of ablation procedures is still unclear. OBJECTIVE: To investigate sex-based differences in outcomes and complications after AF catheter ablation, with a significant female cohort METHOD: In this retrospective study, patients undergoing AF ablation from January 1, 2014, to March 31, 2021, were included. We investigated clinical characteristics, duration and progression of AF, number of EP appointments from diagnosis to ablation, procedural data, and procedure complications. RESULTS: Total of 1346 patients underwent first catheter ablation for AF during this period, including 896 (66.5%) male and 450 (33.4%) female patients. Female patients were older at the time of ablation (66.2 vs. 62.4 years; p < .001). Women had higher CHA2 DS2 -VASc (congestive heart failure, hypertension, age, diabetes, stroke, vascular disease, sex category) scores (3 vs. 2; p < .001) than men, expectedly, as the female sex warrants an additional point. 25.3% female patients had PersAF at the time of diagnosis versus 35.3% male patients (p < .001). At the time of ablation, 31.8% female patients had PersAF as compared to 43.1% male patients (p < .001), indicating progression of PAF to PersAF in both sexes. Women tried more AADs than men before ablation (1.13 vs. 0.98; p = .002). Male and female patients had no statistically significant difference in (a) arrhythmia recurrence at 1-year post ablation (27.7% vs. 30%; p = .38) or (b) procedural complication rate (1.8% vs. 3.1%; p = .56). CONCLUSION: Female patients were older and had higher CHA2 DS2 -VASc scores compared to males at the time of AF ablation. Women tried more AADs than men before ablation. One-year arrhythmia recurrence rates and procedural complications were similar in both sexes. No sex-based differences were observed in safety and efficacy of ablation.

Radiofrequency versus cryoballoon catheter ablation in patients with persistent atrial fibrillation: A randomized trial.

INTRODUCTION: Patients with persistent atrial fibrillation (AF) represent a challenging population for rhythm control therapies. Catheter ablation (CA) with pulmonary vein isolation (PVI) is an effective treatment option for the reduction of the arrhythmic burden. Data regarding the comparability between radiofrequency (RF) and cryoballoon ablation (CRYO) in persistent AF are limited. METHODS: This is a prospective, randomized, single-center study designed to compare the efficacy in terms of rhythm control between RF and CRYO in persistent AF. Eligible participants were randomized 2:1 in two arms: RF and CRYO. The primary endpoint of the study was arrhythmia relapse in the early postprocedural period (first 3 months) and in the middle term follow-up (3 months to 12 months). Secondary endpoints included procedure duration, fluoroscopy time, and complications. RESULTS: A total of 199 patients participated in the study (133 patients in the RF arm, 66 in the CRYO arm). No statistically significant difference occurred between the two groups regarding the primary endpoint (recurrences ≤3 months: 35.5% RF vs. 37.9% CRYO, p .755, recurrences >3 months: 26.3% RF vs. 27.3% CRYO, p .999). From the secondary endpoints, CRYO was a procedure of significantly shorter duration (75.15 ± 17.21 in CRYO vs. 136.6 ± 43.33 in RF group, p < .05). CONCLUSION: CRYO and RF ablation appear to be equally effective for rhythm control in patients with persistent AF. CRYO ablation is advantageous in terms of procedure duration.

Differential gap location after radiofrequency versus cryoballoon pulmonary vein isolation: Insights from a randomized trial with protocol-mandated repeat procedure.

INTRODUCTION: Reconnections to pulmonary vein (PV) triggers of atrial fibrillation (AF) are the primary cause of AF recurrence after PV isolation (PVI) with radiofrequency (RF) or cryoballoon catheter ablation (CRYO), but method-specific contributions to PV reconduction pattern and conductive gap location are incompletely understood. METHODS: The objective of this radiofrequency versus cryoballoon catheter ablation for paroxysmal atrial fibrillation substudy was to determine procedure-specific patterns of PV reconduction in a randomized population with protocol-mandated repeat procedures, irrespective of AF recurrence. Each PV was assessed in turn and PV reconnection sites were identified by high-density electroanatomical mapping and locating the earliest activation site. Gap locations were verified by PV re-isolation. RESULTS: In 98 patients, 81% versus 76% previously isolated PVs remained isolated after CRYO versus RF (risk ratio [RR]: 1.06; 95% confidence interval [CI]: 0.96-1.18; p = .28). There were no significant differences for any PV: left superior PV: 90% versus 80%; left inferior PV: 80% versus 78%; right superior PV: 81% versus 80%, and right inferior PV: 76% versus 73%. For each reconnected PV, 34% of ipsilateral PVs were also reconnected after CRYO compared with 64% after RF (RR: 0.54; 95% CI: 0.32-0.90; p = .01). After RF, gaps were clustered by the carina and adjacent segments, whereas they were more heterogeneously distributed after CRYO. CONCLUSION: Although RF and CRYO produce similar proportions of durably isolated PVs, gap locations appear to develop in procedure-specific patterns. After RF, ipsilateral PV reconduction is more frequent and gap sites cluster by the carina, suggesting that this region should be selectively ablated for more durable PVI.

Acute procedural efficacy and safety of a novel cryoballoon for the treatment of paroxysmal atrial fibrillation: Results from the POLAR ICE study.

INTRODUCTION: Pulmonary vein isolation (PVI) is well established as a primary treatment for atrial fibrillation (AF). The POLAR ICE study was designed to collect prospective real world data on the safety and effectiveness of the POLARxTM cryoballoon for PVI to treat paroxysmal AF. METHODS: POLAR ICE, a prospective, non-randomized, multicenter (international) registry (NCT04250714), enrolled 399 patients across 19 European centers. Procedural characteristics, such as time to isolation, cryoablations per pulmonary vein (PV), balloon nadir temperature, and occlusion grade were recorded. PVI was confirmed with entrance block testing. RESULTS: Data on 372 de novo PVI procedures (n = 2190 ablations) were collected. Complete PVI was achieved in 96.8% of PVs. Procedure and fluoroscopy times were 68.2 ± 24.6 and 15.6 ± 9.6 min, respectively. Left atrial dwell time was 46.6 ± 18.3 min. Grade 3 or 4 occlusion was achieved in 98.2% of PVs reported and 71.2% of PVs isolation required only a single cryoablation. Of 2190 cryoapplications, 83% had a duration of at least 120 s; nadir temperature of these ablations averaged -56.3 ± 6.5°C. There were 6 phrenic nerve palsy events, 2 of which resolved within 3 months of the procedure. CONCLUSION: This real-world usage data on a novel cryoballoon suggests this device is effective, safe, and relatively fast in centers with cryoballoon experience. These data are comparable to prior POLARx reports and in keeping with reported data on other cryoballoons. Future studies should examine the long-term outcomes and the relationship between biophysical parameters and outcomes for this novel cryoballoon.

Safety and efficacy of intracardiac echocardiography-guided zero-fluoroscopic cryoballoon ablation for atrial fibrillation: a prospective randomized controlled trial.

AIMS: The development of intracardiac echocardiography (ICE) has enabled fluoroless atrial fibrillation (AF) ablation using three-dimensional electroanatomical mapping systems. However, fluoroless cryoballoon ablation (CBA) remains challenging, mainly because of the lack of a visual mapping system. Hence, this study aimed to investigate the safety and efficacy of fluoroless CBA for AF under ICE guidance. METHODS AND RESULTS: Patients (n = 100) who underwent CBA for paroxysmal AF were randomly assigned to zero-fluoroscopic (Zero-X) and conventional groups. Intracardiac echocardiography was used to guide the transseptal puncture and catheter and balloon manipulation in all enrolled patients. The patients were prospectively followed for 12 months after CBA. The mean age was 60.4 years, and the left atrial (LA) size was 39.4 mm. Pulmonary vein isolation (PVI) was achieved in all patients. In the Zero-X group, fluoroscopy was used in only one patient because of unstable phrenic nerve capture during right-sided PVI. The procedure time and LA indwelling time in the Zero-X group were not statistically different compared with that in the conventional group. Fluoroscopic time (9.0 vs. 0.008 min) and radiation exposure (29.4 vs. 0.02 mGy) were significantly shorter in the Zero-X group than in the conventional group (P < 0.001). The complication rate did not differ between the two groups. During a mean follow-up of 663.3 ± 172.3 days, the recurrence rate was similar (16.0 vs. 18.0%; P = 0.841) between the groups. Multivariate analysis revealed that LA size was the only independent predictor of clinical recurrence. CONCLUSION: Intracardiac echocardiography-guided fluoroless CBA for AF was a feasible strategy without compromising acute and long-term success or complication rates.