Cryoballoon Procedure Research Articles

Coronary sinus signal amplitude: A predictor of the atrial substrate and low voltage areas.

Low voltage areas (LVA) are pivotal in atrial fibrillation (AF) pathogenesis, influencing local left atrial LA excitation and perpetuating AF occurrences. While pulmonary vein isolation (PVI) with cryo-balloon (CB) ablation is effective for AF, it doesn't provide insights into the LA substrate or detect LVA, which affects ablation success rates. This study examines whether LA voltage and LVAs can be anticipated by analyzing the voltage signal amplitude at the coronary sinus (CS) catheter, which is standard in CB and radiofrequency ablation procedures. A retrospective analysis of 284 patients with recurrent AF undergoing RF catheter ablation was conducted at a high-volume EP center in Germany. The correlation between LA voltage and LVA with the CS signal was explored. The signal amplitude in the CS significantly correlated with voltage in LA walls, particularly in the proximal CS (correlation coefficient ρ=0.81, p<0.001). A CS signal cut-off of 1.155mV effectively predicted severe atrial LVAs (>40%) with a sensitivity of 90.7% and a specificity of 100%. While a threshold of 1.945mV identified patients with no significant atrial LVAs (<5%) with a sensitivity of 88% and a specificity of 50% (AUC: 0.81, 95% CI: 0.71-0.89, p<0.001). The CS signal amplitude is associated with the LA voltage. Due to its potential as a diagnostic tool for atrial LVAs, the signal amplitude in the CS could provide valuable information about the LA substrate, especially when 3D mapping is not feasible.

Diaphragm movement sensor for phrenic nerve monitoring during cryoballoon procedures: the first clinical evaluation.

Right phrenic nerve palsy is the most frequent complication of cryoballoon procedures. The SMARTFREEZE™ console (Boston Scientific, St. Paul, MN, USA) has integrated a new tool for diaphragm monitoring-the Diaphragm Movement Sensor; however, it has not been evaluated in clinical practice. We aimed to assess the diagnostic performance of the Diaphragm Movement Sensor based on compound motor action potential data recorded simultaneously. Thirty consecutive patients (mean age 63.2 ± 10.2 years) were included. We simultaneously recorded the compound motor action potential and the Diaphragm Movement Sensor during cryoapplications in the right pulmonary veins. The right phrenic nerve was paced at 60 per minute, 12 V and 2.9 ms. Compound motor action potential monitoring with a 30% decrease cutoff for the diagnosis of phrenic nerve threatening was considered the gold standard. The Diaphragm Movement Sensor decrease threshold was also set at 30%. Considering compound motor action potential monitoring, phrenic nerve threatening occurred 11 times (in seven patients) among 84 cryoapplications (13.1%) at the right pulmonary veins. The sensitivity and specificity of the Diaphragm Movement Sensor were, respectively, 33% (95% CI: 7%-70%) and 49% (95% CI: 38%-61%; P < 0.001). The predictive positive and negative values for the Diaphragm Movement Sensor were, respectively, 7% (95% CI: 2%-20%) and 86% (95% CI: 72%-95%). The Diaphragm Movement Sensor gave an erroneous diagnosis in 44/84 cryoapplications (52.4%). The diagnostic performance of the Diaphragm Movement Sensor is low, and the relevance of its use in clinical practice may be debated.

Distinguishing cardiac catheter ablation energy modalities by applying natural language processing to electronic health records.

Aim: Catheter ablation is used to treat symptomatic atrial fibrillation (AF) and is performed using either cryoballoon (CB) or radiofrequency (RF) ablation. There is limited real world data of CB and RF in the USas healthcare codes are agnostic of energy modality. An alternative method is to analyze patients' electronic health records (EHRs) using Optum's EHR database. Objective: To determine the feasibility of using patients' EHRs with natural language processing (NLP) to distinguish CB versus RF ablation procedures. Data Source: Optum® de-identified EHRdataset, Optum® Cardiac Ablation NLP Table. Methods: This was a retrospective analysis of existing de-identified EHR data. Medical codes were used to create an ablation validation table. Frequency analysis was used to assess ablation procedures and their associated note terms. Two cohorts were created (1) index procedures, (2) multiple procedures. Possible note term combinations included (1) cryoablation (2) radiofrequency (3) ablation, or (4) both. Results: Of the 40,810 validated cardiac ablations, 3777 (9%) index ablation procedures had available and matching NLP note terms. Of these, 22% (n=844) were classified as ablation, 27% (n= 1016) as cryoablation, 49% (n=1855) as radiofrequency ablation, and 1.6% (n=62) as both. In the multiple procedures analysis, 5691 (14%) procedures had matching note terms. 24% (n=1362) were classified as ablation, 27% as cryoablation, 47% as radiofrequency ablation, and 2% as both. Conclusion: NLP has potential to evaluate the frequency of cardiac ablation by type, however, for this to be a reliable real-world data source, mandatory data entry by providers and standardized electronic health reporting must occur.

Manifold analysis of the P-wave changes induced by pulmonary vein isolation during cryoballoon procedure

Background/Aim:In atrial fibrillation (AF) ablation procedures, it is desirable to know whether a proper disconnection of the pulmonary veins (PVs) was achieved. We hypothesize that information about their isolation could be provided by analyzing changes in P-wave after ablation. Thus, we present a method to detect PV disconnection using P-wave signal analysis. Methods:Conventional P-wave feature extraction was compared to an automatic feature extraction procedure based on creating low-dimensional latent spaces for cardiac signals with the Uniform Manifold Approximation and Projection (UMAP) method. A database of patients (19 controls and 16 AF individuals who underwent a PV ablation procedure) was collected. Standard 12-lead ECG was recorded, and P-waves were segmented and averaged to extract conventional features (duration, amplitude, and area) and their manifold representations provided by UMAP on a 3-dimensional latent space. A virtual patient was used to validate these results further and study the spatial distribution of the extracted characteristics over the whole torso surface. Results:Both methods showed differences between P-wave before and after ablation. Conventional methods were more prone to noise, P-wave delineation errors, and inter-patient variability. P-wave differences were observed in the standard leads recordings. However, higher differences appeared in the torso region over the precordial leads. Recordings near the left scapula also yielded noticeable differences. Conclusions:P-wave analysis based on UMAP parameters detects PV disconnection after ablation in AF patients and is more robust than heuristic parameterization. Moreover, additional leads different from the standard 12-lead ECG should be used to detect PV isolation and possible future reconnections better.

Abstract 12149: Assessment of Cryoballoon Occlusion Shift From the Pulmonary Vein Ostium Following Freeze Initiation Using a Dielectric Imaging System

Introduction: Cryoballoon ablation for atrial fibrillation (AF) has been widely adopted clinically. However, dislodgement from the pulmonary vein (PV) ostium following freeze initiation commonly occurs due to a sudden rise in balloon pressure, known as the “pop-out” phenomenon. This can often only be partially detected using continuous color Doppler or repeat angiography after the initiation of freeze. We aim to access the incidence of this phenomenon using the dielectric imaging system in comparison to intracardiac echocardiography (ICE). Methods: Ten patients underwent de novo cryoballoon ablation for paroxysmal or persistent AF with the use of the KODEX-EPD dielectric imaging system (Philips, Amsterdam, Netherlands). A baseline assessment and injection were performed pre-ablation followed by analysis of occulsion via the KODEX Occlusion Viewer. Simultaneous assessment was performed by the operator utilizing ICE. Repeat assessment with injection was performed after ablation start to assess whether the cryoballoon remained occluded on ICE and by KODEX’s occlusion assessment. Results: There was a high correlation between KODEX and ICE for assessment of balloon occlusion prior to ablation (91.7±23.6%). KODEX demonstrated an overall sensitivity (88.6%), specificity (75.0%), positive predictive value (76.5%), and negative predictive value (87.8%) of the occlusion tool validated by ICE. Both imaging modalities detected a leak after initial full occlusion, an incidence of 24.3% on Kodex and 23.8% on ICE. Conclusions: Balloon contact with the PV is vital for an effective, transmural lesion. The dielectric imaging system and ICE confirmed high incidence of this “pop-out” phenomenon, which can lead to incomplete PV isolation. The KODEX-EPD occlusion tool is highly sensitive and specific to assist in the identification of this phenomenon and may improve the outcome for cryoballoon procedures. In the future a more compliant cryoballoon design, without a shift in balloon pressure during ablation, may avoid this phenomenon.

Incidence of Long-Term Pulmonary Vein Reconnection after a 2-Minute Cryoballoon Freeze for Pulmonary Vein Isolation—Invasive Insights of TTI-Dependent Cryoenergy Titration

Introduction: The optimal freeze duration in cryoballoon pulmonary vein isolation (PVI) is unknown. TTI-based titration of cryoenergy allows individualized freeze duration and has emerged as a favorable ablation strategy in PV cryoablation. In a recent study, we demonstrated that omission of a bonus freeze and reduction in freeze duration to a minimum of 2 min in the case of short TTI led to comparable arrhythmia recurrence rates. Whereas clinical outcome seems to be comparable to fixed freeze duration, evidence of long-term PV reconnection rates in patients undergoing TTI-based cryoballoon ablation is sparse. Aim of the study: To evaluate the procedural efficacy of a single 2-min freeze for PVI, we assessed PV conduction recovery after cryoballoon PVI with a TTI-guided titration of freeze duration compared to a fixed ablation protocol. Methods and Results: We included consecutive patients with atrial fibrillation (AF) recurrence undergoing a second ablation procedure after the initial cryoballoon procedure. The second AF ablation procedure was performed by the 3D-mapping system and radiofrequency ablation technique. A total of 219 patients (age: 66.2 ± 10.8 years, 53% female, paroxysmal AF: 53%) treated with the TTI-guided protocol (174 patients, 685 PV) or fixed protocol (45 patients, 179 PV) showed comparable total reconnection rates (TTI: 36.9% vs. fixed: 31.8%, p = 0.21). The PV reconnection rate was not statistically different for PVs treated with a 2-min freeze in case of short TTI, compared to longer freeze duration. Interestingly, the PV reconnection rate was lower in LIPVs treated with the fixed protocol (13% vs. 31%, p = 0.029). In the TTI group, 17 out of 127 patients (15%) had durable isolation of all PVs, whereas in 8 out of 40 patients (20%) in the fixed group, all PVs were still isolated (p = 0.31). Conclusions: overall reconnection rate was not different using a TTI-guided ablation protocol compared to a fixed ablation protocol, whereas the LIPV reconnection rate was significantly lower in patients treated with a fixed ablation protocol.

Use of a novel integrated dilator-needle system in cryoballoon procedures: a zero-exchange approach

BackgroundRecently, a novel integrated dilator-needle system (AcQCross Qx, Acutus Medical) was introduced to reduce the number of exchanges for a transseptal access. This system can be used in combination with large bore sheaths. In this pilot study, we evaluated the safety and efficacy of a zero-exchange approach with the AcQCross system in cryoballoon procedures.MethodsIn this retrospective single-center study, we included 40 patients (AcQCross: n = 20; control group: n = 20) who underwent a cryoballoon procedure for the treatment of atrial fibrillation. In the AcQCross and control group, patients underwent ablation with POLARx (Boston Scientific) and Arctic Front Advance Pro (AFA-Pro, Medtronic) in equal numbers (n = 10). In the AcQCross group, the AcQGuide Max sheath (Acutus Medical) was used in all POLARx cases.ResultsThe baseline characteristics of the study population were comparable between groups. In the AcQCross group, there was a reduction in procedure time (49.7 ± 9.0 min vs. 59.6 ± 8.1 min, P < 0.001) and time from puncture until balloon delivery (15.5 ± 6.8 min vs. 21.5 ± 7.4 min, P = 0.01) in comparison with the control group. The balloon in body time, fluoroscopy time, number of cryoapplications, and biophysical parameters were similar between groups. There was one temporary phrenic nerve injury in the AcQCross group. Importantly, no signs of air embolism were noted with the AcQGuide Max sheath.ConclusionsThe use of the novel AcQCross system improves procedural efficacy in cryoballoon procedures by reducing the number of exchanges.

Randomised comparison of achieve and traditional circular mapping catheters in cryoballoon ablation: results at up to a decade

Abstract Funding Acknowledgements Type of funding sources: None. Background A single-centre trial randomised patients to the use of the Achieve mapping catheter or a traditional circular mapping catheter during cryoballoon procedures for paroxysmal atrial fibrillation (AF) in 2011-2014. Long-term outcomes from the cohort were determined in 2021. Purpose To evaluate the determinants of long-term outcome of ablation for paroxysmal AF. Methods Patient and study procedure characteristics and clinical outcomes were determined, including mapping catheter assignment, model of cryoballoon used, AF recurrence, repeat ablations required, findings at repeat ablation long term survival of the patient. Results Of 102 patients in the original study, 98 had long-term (4.11+/-2.82 years) follow up data available. 35 patients (35.7%) had AF recurrence, giving a long-term success rate at 64.3% after 1 ablation, increasing to 81.6% after repeat ablation. Of the study cohort n=8 (8.16%) died at a median of 4.9 years after ablation (IQR:1.7-5.7). 25/98 (25.5%) patients had a second ablation and 7 (7.1%) had a third or more ablations. Those who had AF recurrence were older, with a higher prevalence of prior ischaemic heart disease and cardiac device implantation (p=0.02-0.03). After multi-variate analysis, a prior implanted cardiac device was the only significant predictor of recurrence (p=0.03). Conclusion Long-term outcomes after a 1st time PAF cryoablation were similar regardless of the type of mapping catheter used, the generation of cryoballoon, and traditional procedure endpoints. AF recurrences were more often detected in older patients with a history of ischaemic heart disease and implanted cardiac devices.

PO-711-03 A RANDOMISED COMPARISON OF METHODOLOGY IN CRYOBALLOON ABLATION FOR ATRIAL FIBRILLATION: RESULTS AT UP TO A DECADE

A single-centre randomized trial investigated the value of the Achieve mapping catheter in cryoballoon procedures for paroxysmal atrial fibrillation (AF) in 2011-2014. Long-term outcomes from the cohort were determined. To evaluate the predictors of long-term outcome after a cryoballoon ablation for paroxysmal atrial fibrillation. Study patients were randomly assigned to Achieve versus Lasso guided cryoballoon ablation. Patient and study procedure characteristics and clinical outcomes were determined, including AF recurrence, repeat ablations and characteristics and death. Of 102 patients in the original study, 98 had long-term (4.11+/-2.82 years) follow up data available. 35 patients (35.7%) had AF recurrence, giving a long-term success rate at 64.3% after 1 ablation, increasing to 81.6% after repeat ablation. n=8 (8.16%) of the study cohort died at a median of 4.9 years after ablation (IQR:1.7-5.7). 25/98 (25.5%) patients had a second ablation and 7 (7.1%) had subsequent ablation. Those who had AF recurrence were older, with a prior history of ischaemic heart disease and cardiac device implantation (p=0.02-0.03). After multi-variate analysis, a prior implanted cardiac device was the only significant predictor of recurrence (p=0.03). Long-term outcomes after a 1st time PAF cryoablation were similar regardless of generation of cryoballoon, type of mapping catheter used and traditional procedure endpoints. AF recurrences were more likely to occur in older patients with a history of ischaemic heart disease and implanted cardiac devices.

Diaphragmatic CMAP Monitoring During Cryoballoon Procedures: Surface vs. Hepatic Recording Comparison and Limitations of This Approach.

BackgroundCompound motor action potential (CMAP) monitoring is a common method used to prevent right phrenic nerve palsy during cryoballoon ablation for atrial fibrillation.ObjectiveWe compared recordings simultaneously obtained with surface and hepatic electrodes.MethodsWe included 114 consecutive patients (mean age 61.7 ± 10.9 years) admitted to our department for cryoballoon ablation. CMAP was monitored simultaneously with a hepatic catheter and a modified lead I ECG, whilst right phrenic nerve was paced before (stage 1) and during (stage 2) the right-sided freezes. If phrenic threat was detected with hepatic recordings (CMAP amplitude drop >30%) the application was discontinued with forced deflation.ResultsThe ratio of CMAP/QRS was 4.63 (2.67–9.46) for hepatic and 0.76 (0.55–1.14) for surface (p < 0.0001). Signal coefficients of variation during stage 1 were 3.92% (2.48–6.74) and 4.10% (2.85–5.96) (p = 0.2177), respectively. Uninterpretable signals were more frequent on surface (median 10 vs. 0; p < 0.0001). For the 14 phrenic threats, the CMAP amplitude dropped by 35.61 ± 8.27% on hepatic signal and by 33.42 ± 11.58% concomitantly on surface (p = 0.5417). Our main limitation was to achieve to obtain stable phrenic capture (57%). CMAP monitoring was not reliable because of pacing instability in 15 patients (13.16%). A palsy occurred in 4 patients (3.51%) because cryoapplication was halted too late.ConclusionBoth methods are feasible with the same signal stability and amplitude drop precocity during phrenic threats. Clarity and legibility are significantly better with hepatic recording (sharper signals, less far-field QRS). The two main limitations were pacing instability and delay between 30% CMAP decrease and cryoapplication discontinuation.

Pulmonary vein isolation for atrial fibrillation: Does ablation technique influence outcome?

BackgroundOver the last 20 years various techniques have been developed striving for safer and more durable pulmonary vein isolation (PVI). The three most commonly used tools are pulmonary vein ablation catheter (PVAC) and cryoballoon (‘single-shot’ techniques), and point-by-point (PBP) radiofrequency ablation using 3D electroanatomical mapping (EAM). ObjectiveEvaluate the safety and efficacy of the different techniques in an unselected population undergoing de-novo ablation for persistent or paroxysmal atrial fibrillation (AF) at Royal Papworth Hospital (RPH). MethodRetrospective, single-centre study of consecutive AF ablations at RPH between March 2017 and April 2018. Demographic, procedural and outcome data were analysed. ResultsOver the study period 329 first-time PVI procedures were performed. 37.4% were performed using PBP, 39.8% using cryoballoon and 22.8% using PVAC. There was no significant difference in age or sex between different ablation technique groups. 238 procedures were performed for paroxysmal AF and 91 for persistent AF. A higher proportion of the persistent cases were performed using point-by-point techniques compared to paroxysmal cases (58.2% vs 29.0%, p < 0.05).Procedural times were significantly longer in the group undergoing PBP ablation compared to cryoballoon or PVAC. However, there was no statistically significant difference in 12-month freedom from symptomatic AF or procedural complications between the groups. ConclusionsPBP, PVAC and cryoballoon AF ablation all appeared equally efficacious in an unselected population, though PVAC and cryoballoon procedures were shorter. All procedures were associated with a low adverse event rate. Prospective examination is required to substantiate this finding.

Cryoballoon atrial fibrillation ablation experience in Japan.

In Japan, cryoballoon ablation has been widely accepted and more than 70 000 patients have undergone pulmonary vein isolation using this novel technology since the introduction. This review focused on the current status of cryoballoon ablation in Japan and clarified the characteristics as compared to Europe and the United States. The number of atrial fibrillation patients undergoing cryoballon ablation has rapidly increased over the last 6 years. Most of the Japanese physicians consider the indication of cryoballoon ablation based on the anatomy of the pulmonary veins and left atrium evaluated on preprocedural computed tomography, and often perform adjunctive radiofrequency ablation after the pulmonary vein isolation. The reported overall efficacy and safety were similar to that in Europe and the United States; however, there are some distinctive complications of the cryoballoon procedure in Japan, such as air embolisms, gastric hypomotility and coronary artery spasms. Currently, the cryoballoon pulmonary vein isolation is widely accepted in Japan owing to the low incidence of lethal complications, shorter procedure time and acceptable single procedure atrial fibrillation freedom.

Durability of a right superior pulmonary vein isolation after an inevitably interrupted single short freeze during cryoballoon ablation

In cryoballoon ablation, applications for right superior pulmonary veins (RSPVs) inevitably need to be interrupted for some safety reasons. We retrospectively investigated the RSPV isolation durability after single interrupted short freezes. Data from 30 patients who underwent repeat procedures 8.2 (4.1-13.8) months after an inevitably interrupted single short freeze (<180 s) for RSPVs during the index cryoballoon procedures were analyzed. It was interrupted by active deflation due to phrenic nerve injury (PNI) (Group 1: n = 14) or passive deflation due to a balloon temperature of -60°C (Group 2: n = 16). The freezing time was 145 (107-166) and 142 (127-160) s and nadir balloon temperature -50.7 ± 3.6 and -60°C in Groups 1 and 2, respectively. Pulmonary vein isolation was achieved after interrupted freezing in all except in one patient requiring touch-up ablation in Group 1. All PNI was asymptomatic and recovered during the follow-up. Eight/13 (61.5%) and 16/16 (100%) RSPVs were durable during the second procedure in Groups 1 and 2. In Group 1, the freezing time was significantly longer in durable than reconnected RSPVs (p = .032), and the optimal cutoff point for the freezing duration to predict the durability was 94.0 s (sensitivity 100%, specificity 60.0%). When the freezing time was ≥120 s, 80% of the RSPVs were durable. However, when the freezing time was ≤68 s, all RSPVs were reconnected. The feasibility of second cryoapplications for RSPVs should be discussed considering the freezing time of the interrupted initial applications in Group 1, however, it was not necessary in Group 2.

Near zero fluoroscopy in cryoballoon catheter ablation in patients with atrial fibrillation using the new KODEX-EPD imaging system

Abstract Funding Acknowledgements Type of funding sources: None. Background. Fluoroscopy is commonly used in cryoballoon catheter ablation for pulmonary vein (PV) isolation procedures in patients with atrial fibrillation (AF). Objective The purpose of this study was to verify the feasibility of a new dielectric imaging system in reducing the radiation exposure during cryoballoon ablation in patients with AF. Methods We enrolled 26 consecutive patients with paroxysmal AF: 13 patients underwent the procedure under fluoroscopy guidance before the new system introduction, while 13 patient underwent the procedure under fluoroscopy and KODEX-EPD system guidance with its occlusion tool software. After transseptal access a detailed image reconstruction of left atrium and PVs was achieved with the Achieve octapolar circular mapping catheter and the cryoablation was performed with the Arctic Front Advance cryoballoon. Results Total time of the procedure was comparable between the two groups (90.15 ± 28.67 vs 80.77 ± 17.17 using KODEX-EPD, p = 0.34), while fluoroscopy time was significantly lower in the group using KODEX-EPD (16.92 ± 8.96 vs 5.54 ± 2.06, p &amp;lt; 0.01). Acute isolation was achieved in all PVs. No 30 days complication was observed. Conclusion This is the first study that demonstrates the feasibility of a reduce fluoroscopy workflow using the novel KODEX-EPD system in a cryoballoon procedure. Abstract Figure. Fluoroscopy time

Pulmonary vein isolation for AF: does technique influence outcome?

Abstract Funding Acknowledgements Type of funding sources: None. Background Over the last 20 years various techniques have been developed striving for safer and more durable pulmonary vein isolation (PVI). The three most commonly used tools are pulmonary vein ablation catheter (PVAC) and cryoballoon (‘single-shot’ techniques), and point-by-point (PBP) radiofrequency ablation using 3D electroanatomical mapping (EAM). Objective Evaluate the safety and efficacy of the different techniques in an unselected population undergoing de-novo ablation for persistent or paroxysmal atrial fibrillation (AF) at a single high-throughput centre. Method Retrospective, single-centre study of consecutive AF ablations between March 2017 and April 2018. Demographic, procedural and outcome data were analysed. Results Over the study period 329 first-time PVI procedures were performed. 37.4% were performed using PBP, 39.8% using cryoballoon and 22.8% using PVAC. There was no significant difference in age or sex between different ablation technique groups. 238 procedures were performed for paroxysmal AF and 91 for persistent AF. A higher proportion of the persistent cases were performed using point-by-point techniques compared to paroxysmal cases (58.2% vs 29.0%, p &amp;lt; 0.05). Procedural times were significantly longer in the group undergoing PBP ablation compared to cryoballoon or PVAC. However, there was no statistically significant difference in 12-month freedom from symptomatic AF or procedural complications between the groups. Conclusions PBP, PVAC and cryoballoon AF ablation all appeared equally efficacious in an unselected population, though PVAC and cryoballoon procedures were shorter. All procedures were associated with a low adverse event rate. Prospective examination is required to substantiate this finding. Table 1CARTOn= 123Cryoballoonn= 131PVACn = 75p-valueAge/years61.7 ± 9.259.5 ± 10.661.7 ± 9.70.14Male92 (74.8)88 (67.2)49 (61.3)0.80Paroxysmal AF70 (56.9)106 (78.6)62 (82.7)0.14Cardiovascular risk factors Hypertension Diabetes Ischaemic heart disease Cerebrovascular disease Heart failure Dyslipidaemia73 (59.3)23 (18.7)40 (32.5)2 (1.6)0 (0) 12 (9.8)79 (60.3)19 (14.5)45 (34.4)0 (0)1 (0.8)16 (12.2)43 (57.3)16 (21.3)22 (29.3)1 (1.3)0 (0)10 (13.3) 0.58 0.24 0.62 - - 0.71Left atrial diameter/cm4.2 ± 0.74.1 ± 0.73.9 ± 1.00.69Procedure time/mins191.3 ± 39126.7 ± 24117.4 ± 30&amp;lt;0.056 month success Paroxysmal Persistent50/66 (75.8)32/51 (62.7)78/103 (75.7)18/24 (75.0)48/61 (78.6)10/12 (83.3) 0.99 0.80Complications9 (7.3)3 (2.3)1 (1.3)0.07Patient demographics, procedural characteristics and outcomes for Carto, cryoballoon and PVAC cases. Values presented as mean ± SD or n (%)Abstract Figure. Time to arrhythmia recurrence

Newer generation cryoballoon vs. contact force-sensing radiofrequency ablation catheter in the ablation of paroxysmal atrial fibrillation

Catheter ablation for atrial fibrillation (AF) has become an effective treatment to control symptoms. The second generation cryoballoon (CB) was designed for more efficient and homogenous freeze. Radiofrequency (RF) ablation catheters using three-dimensional electroanatomical mapping with the use of contact-force radiofrequency (CF RF) technology has achieved good results in several studies. To compare the efficacy and safety of second-generation CB ablation in contrast to CF RF ablation in the ablation of paroxysmal AF. A total of 81consecutive patients suffering from paroxysmal AF underwent pulmonary vein isolation (PVI) either by the second generation cryoballoon (n = 44) or acontact force-sensing RF catheter (n = 37). The study was conducted at Ain Shams University Hospitals and Royal Brompton & Harefield NHS trust. Baseline data, procedural data and patient follow up-at 3, 6 and 12months-were collected and analysed. The mean age was 53.8 ± 15years in the CB group and 62.4 ± 12years in the RF group, females representing 40.9% and 48.6% respectively. The baseline characteristics were comparable, but the CB group had less left atrial diameter and more left ventricular ejection fraction. The CB procedure was shorter (94.4 ± 39.3 vs. 140.8 ± 44.3 min, p < 0.0001), with longer fluoroscopy time (30 vs. 15.1 min, p = 0.047). Procedural complications were comparable between the two groups (CB 4.6%, CF RF 2.7%, p = 0.411). After 1year, the recurrence rate in the CB group was similar to RF (27.3% vs. 27% respectively, p = 0.980). Second-generation CB ablation of paroxysmal AF has similar efficacy and safety to contact force-sensing RF catheters, with shorter procedure times and more fluoroscopy.

Safety and efficacy of cryoballoon ablation for the treatment of paroxysmal and persistent AF in a real-world global setting: Results from the Cryo AF Global Registry.

BackgroundCryoballoon ablation is a commonly used approach to treat patients with atrial fibrillation (AF).ObjectivesReport on the safety and efficacy of cryoballoon ablation for the treatment of AF in the largest global cohort of cryoablated patients prospectively studied within a single registry.MethodsThe Cryo AF Global Registry is a prospective, multi‐center registry. Patients with paroxysmal AF (PAF) or persistent AF (PsAF) were treated with the cryoballoon catheter according to routine practices at 93 sites across 36 countries. Primary efficacy endpoints included freedom from AF and freedom from AF/atrial flutter (AFL)/atrial tachycardia (AT) ≥30 seconds. The primary safety endpoint was serious device‐ or procedure‐related adverse events over 12 month follow‐up.ResultsDuring this evaluation window, 2922 subjects completed an index cryoballoon procedure, and 1440 completed 12 month follow‐up. The cohort was 61 ± 12 years of age, 36.3% female, and 78.7% PAF. Serious device‐ and procedure‐related adverse event rates were 1.5% and 3.4%, respectively. Freedom from AF/AFL/AT after the 90 day blanking period was 86.4% (95% CI: 84.3%‐88.3%) in patients with PAF and 70.9% (95% CI: 64.6%‐76.4%) in patients with PsAF. Freedom from AF/AFL/AT in first‐line PAF and PsAF was 90.0% (95% CI: 86.4%‐92.7%) and 72.9% (95% CI: 58.6%‐83.0%) at 12 months, respectively.ConclusionsThe Cryo Global AF Registry is the largest evaluation to demonstrate cryoablation is an efficient, safe, and effective treatment for patients with AF worldwide. Cryoablation was commonly used to treat patients prior to an AAD failure and may facilitate earlier therapy for patients on the AF disease continuum.

Near zero fluoroscopy cryoballoon catheter ablation in patients with atrial fibrillation using a novel dielectric imaging system

Abstract Background Fluoroscopy is commonly used in cryoballoon catheter ablation for pulmonary vein (PV) isolation procedures in patients with atrial fibrillation (AF). Purpose The purpose of this study was to verify the feasibility of a new dielectric imaging system in reducing the radiation exposure during cryoballoon ablation in patients with AF. Methods We enrolled 40 consecutive patients with paroxysmal AF: 20 patients underwent the procedure under fluoroscopy guidance before the new system introduction, while 20 patient underwent the procedure under fluoroscopy and a new dielectric imaging system guidance with its occlusion tool software. After transseptal access a detailed image reconstruction of left atrium and PVs was achieved with an octapolar circular mapping catheter and the cryoablation was performed with a cryoballoon catheter. Results Total time of the procedure was comparable between the two groups (90.15±28.67 vs 80.77±17.17 using the dielectric imaging system, p=0.34), while fluoroscopy time was significantly lower in the group using the new dielectric imaging system (16.92±8.96 vs 5.54±2.06, p&amp;lt;0.01). Acute isolation was achieved in all PVs. No 30 days complication was observed. Conclusion This is the first study that demonstrates the feasibility of a reduce fluoroscopy workflow using the novel dielectric imaging system in a cryoballoon procedure. Funding Acknowledgement Type of funding source: None

P1401Electrophysiological findings during repeat procedures in patients exhibiting electrical isolation in all veins after an index cryoballoon procedure for paroxysmal atrial fibrillation

Abstract Introduction The purpose of this study was to analyze and compare the electrophysiological findings in redo radiofrequency (RF)-ablation of AF in a series of patients with durable PV isolation (PVI) and with PV reconnection after index procedure with the second-generation cryoballon (CB). Methods and results A total of 132 patients (81 males, 60.7 ± 12.4 years) who underwent CB-A for paroxysmal AF (PAF) were enrolled. Indication for the redo procedure was symptomatic (PAF) in 83 (63%) and persistent AF (PeAF) or persistent regular atrial tachycardia (RAT) in 49 (37%). Seventy-five (57%) patients presented a PV reconnection (PV group), whereas 57 (43%) no PV reconnection (non-PV group). The non-PV group exhibited significantly more atrial flutters and non-PV foci than the PV group after induction protocol (67% vs. 36%, p = 0.003 and 51% vs. 24% p = 0.002, respectively) (Table 1). Twenty-two (29.3%) patients of the PV group and 20 (35%) patients of the non-PV group had AF/RAT recurrence after a mean follow-up of 12.5 ± 8 months. The survival analysis demonstrated no statistical significance in recurrence between the two groups (log rank p = 0.358). In the cox regression analysis only the AF/RAT recurrence in the blanking period could predict independently an AF/RAT relapse. Conclusions AF/RAT recurrence in patients after CB-A with durable PVI is significantly associated to atrial flutters and non-PV foci. No statistically different success rate regarding AF/RAT freedom was detected between PV and non-PV Group after redo RF-CA. Table 1. Electrophysiological findings PV Groupn = 75 non-PV Groupn = 57 p-value PV trigger (n of patients) 75(100) 0(0) &amp;lt;0.001 LSPV 29 (39) 0 (0) &amp;lt;0.001 LIPV 15 (20) 0 (0) &amp;lt;0.001 RSPV 27 (36) 0 (0) &amp;lt;0.001 RIPV 33 (44) 0 (0) &amp;lt;0.001 Atrial flutters (n of patients) 27 (36) 38 (67) 0.003 Roof-flutter 13 (17) 34 (60) 0.0001 Peri-mitral-flutter 9 (12) 20 (35) 0.003 Right flutter 13 (17) 5 (9) 0.2 Non-PV foci (n of patients) 18 (24) 29 (51) 0.002 Categorical variables are expressed as absolute and percentage (in brackets). LIPV, left inferior pulmonary vein; LSPV, left superior pulmonary vein; PV, pulmonary vein; RSPV, right superior pulmonary vein; RIPV, right inferior pulmonary vein.

Benefit of ultra-high-density mapping-guided radiofrequency reablation in pulmonary vein isolation non-responders after initial cryoballoon procedure.

Symptomatic atrial arrhythmias despite complete pulmonary vein isolation (PVI) are common. The purpose was to evaluate ultra-high-density multi-electrode electroanatomical mapping-guided radiofrequency ablation (RFA) in PVI non-responders. Ultra-high-density multi-electrode electroanatomical mapping-guided RFA in consecutive symptomatic atrial fibrillation (AF) patients after initial cryoballoon PVI was performed. Patients were included if all pulmonary veins (PVs) were still isolated. Radiofrequency targets were atrial tachycardia (AT), extra-PV trigger, and/or substrate. Procedural results and outcome were evaluated. Of 95 patients, 67 (70.5%) with complete PVI were included (70 years, CHA2DS2Vasc 2.9, left atrium 45 mm, persistent AF 45%, AT 45%). The median time to reablation was 26 months. One hundred and seven maps (1.6/patient) and 11.890 ± 9.018 electrograms were acquired in 33 ± 12 min. Twenty-eight percent of the left atrial (LA) wall showed pathological voltage signals, predominantly at the anterior (37%) and septal wall (26%). Atrial tachycardia (49 left, 4 right) were ablated in 35 patients (52%), extra-PV trigger in two patients (3%). One atrioventricular nodal re-entry tachycardia and seven right atrial isthmus ablation (10%) were performed. In 32 patients (48%), no AT was present and substrate-based ablation was performed. Mean LA area ablated was 7 ± 6 cm2 (7%). No major complication occurred. The mean follow-up time was 772 ± 317 days. Freedom from atrial arrhythmia recurrence off antiarrhythmic drugs was 49% at 12 months. Pulmonary vein isolation non-responders are older, mainly suffering from complex atrial arrhythmias. Left atrial substrate is predominantly located at the anterior and septal wall. Ultra-high-density multi-electrode electroanatomical mapping-guided RFA is safe and effective. At 1 year, 5 out of 10 patients were in stable sinus rhythm off antiarrhythmic drugs.