Atrial Fibrillation Ablation Techniques Research Articles

Safety and efficacy of pulse field ablation of atrial fibrillation in patients aged over 75 years

Abstract Introduction Pulse-field ablation (PFA) is an emerging atrial fibrillation (AF) ablation technology associated with a favorable safety profile and short procedural times. Elderly patients, in whom AF ablation indications are expanding, may be particularly suitable to PFA. However, in a recent large multicenter trial, patients older than 75 years were not included, so that data on PFA safety and efficacy in this population are scarce. Methods Consecutive patients who underwent PFA of AF at a single academic center were prospectively included in a local registry. Written informed consent was obtained. Clinical, imaging and procedural data was collected and routine care follow-up was performed locally. Results From 2022, out of 345 consecutive patients who underwent PFA of, 42 (13%) were aged ≥75 years. As compared to <75 years-old patients (mean age 61±3 years), elderly patients (mean age 78±4 years) were more frequently females (21 [51%] vs 121 [40%], P=0.02), had more frequently non-paroxysmal AF (27 [65%] vs 164 [54%], P=0.01), significant cardiac comorbidities (9 [21%] vs 33 [11%], P=0.01), and larger indexed left atrial volumes (65 mL/m2 [interquartile range (IQR) 54-76] vs 61 [IQR 54-68], P=0.04). With regards to procedural parameters, the total procedural length was comparable, while elderly patients received more frequently PFA applications outside the pulmonary veins. The rate of major complications was comparable, but 3 cardiac tamponades occurred in patients aged over 75 years, while none occurred in younger patients. After a median follow-up time of 185 days (IQR 65 – 202), the cumulative freedom from sustained atrial arrhythmia recurrence was not statistically different between patients aged over 75 years (75%, 95% confidence interval (CI) [62-84%]) and under 75 years (75%, 95% CI [62-84%], P=0.11). Conclusions PFA appear as a safe and effective technique for AF ablation in elderly patients, although there was an excess of cardiac tamponades in this group

Incremental Metabolic Benefits from Cryoablation for Paroxysmal Atrial Fibrillation: Insights from Metabolomic Profiling

Background: Cryoablation (CRYO) is a novel catheter ablation technique for atrial fibrillation (AF). However, uncertainty persists regarding the role of metabolic modifications associated with CRYO. This study was aimed at exploring whether CRYO influences the metabolic signature – a possibility not previously investigated. Methods: Paired serum samples from patients with AF (n = 10) were collected before and 24 h after CRYO. Untargeted metabolomic analysis was conducted with LC-MS. Univariate and multivariate analyses were applied to identify differential metabolites between samples. Pathway enrichment and Pearson correlation analyses were performed to reveal the perturbed metabolic pathways and potential interactions. Results: Levels of 19 metabolites showed significant changes between baseline and 24 h after CRYO. Pathway analysis revealed that the perturbed metabolites were enriched in unsaturated fatty acid biosynthesis, retrograde endocannabinoid signaling, and neuroactive ligand-receptor interactions. Pearson correlation analysis indicated strong correlations among differential metabolites, biochemical markers, and clinical indicators. Conclusions: CRYO induces systemic changes in the serum metabolome in patients with paroxysmal AF and provides potential metabolic benefits. Our findings might enable enhanced understanding of the pathophysiology and metabolic mechanisms involved in catheter ablation.

The Year in Hungarian Cardiology 2023: Arrhythmias

In 2023, Hungary produced notable scientific publications focused on cardiac arrhythmias. This review highlights the most impactful papers, authored at least in part by Hungarians, featuring work conducted at Hungarian research sites and published in international peer-reviewed journals. We give a short overview regarding papers dealing with the role of imaging (different types of ultrasound, cardiac magnetic resonance imaging and electroanatomical mapping) in treating cardiac arrhythmias. We summarize the novelties of ischemic complications of atrial fibrillation (AF), cerebral safety of AF ablation, and current AF ablation techniques. Optimizing risk stratification of ventricular tachycardia (VT) ablation was a landmark paper of our “machine learning” research. Further studies have made significant strides in cardiac device therapy, notably through the groundbreaking BUDAPEST-CRT Upgrade Trial for heart failure, which demonstrated marked reductions in deaths and hospitalizations following Cardiac Resynchronization Therapy (CRT) upgrade procedures. Research on the impact of frailty on CRT outcomes has underscored the importance of tailored treatments. Artificial intelligence, particularly topological data analysis, has been crucial in personalizing CRT therapy. Additionally, advancements in remote monitoring and lead extraction techniques have mirrored the rapid evolution of cardiac technology and care.

Impact of high-power short-duration atrial fibrillation ablation technique on the incidence of silent cerebral embolism: a prospective randomized controlled study

BackgroundHigh-power short-duration (HPSD) ablation strategy has emerged as a popular approach for treating atrial fibrillation (AF), with shorter ablation time. The utilized Smart Touch Surround Flow (STSF) catheter, with 56 holes around the electrode, lowers electrode-tissue temperature and thrombus risk. Thus, we conducted this prospective, randomized study to investigate if the HPSD strategy with STSF catheter in AF ablation procedures reduces the silent cerebral embolism (SCE) risk compared to the conventional approach with the Smart Touch (ST) catheter.MethodsFrom June 2020 to September 2021, 100 AF patients were randomized 1:1 to the HPSD group using the STSF catheter (power set at 50 W) or the conventional group using the ST catheter (power set at 30 to 35 W). Pulmonary vein isolation was performed in all patients, with additional lesions at operator’s discretion. High-resolution cerebral diffusion-weighted magnetic resonance imaging (hDWI) with slice thickness of 1 mm was performed before and 24–72 h after ablation. The incidence of new periprocedural SCE was defined as the primary outcome. Cognitive performance was assessed using the Montreal Cognitive Assessment (MoCA) test.ResultsAll enrolled AF patients (median age 63, 60% male, 59% paroxysmal AF) underwent successful ablation. Post-procedural hDWI identified 106 lesions in 42 enrolled patients (42%), with 55 lesions in 22 patients (44%) in the HPSD group and 51 lesions in 20 patients (40%) in the conventional group (p = 0.685). No significant differences were observed between two groups regarding the average number of lesions (p = 0.751), maximum lesion diameter (p = 0.405), and total lesion volume per patient (p = 0.669). Persistent AF and CHA2DS2-VASc score were identified as SCE determinants during AF ablation procedure by multivariable regression analysis. No significant differences in MoCA scores were observed between patients with SCE and those without, both immediately post-procedure (p = 0.572) and at the 3-month follow-up (p = 0.743).ConclusionsInvolving a small sample size of 100 AF patients, this study reveals a similar incidence of SCE in AF ablation procedures, comparing the HPSD strategy using the STSF catheter to the conventional approach with the ST catheter.Trial registrationClinicaltrials.gov: NCT04408716.Graphical AF = Atrial fibrillation, DWI = Diffusion-weighted magnetic resonance imaging, HPSD = High-power short-duration, ST = Smart Touch, STSF = Smart Touch Surround Flow.

Three Ablation Techniques for Atrial Fibrillation during Concomitant Cardiac Surgery: A Systematic Review and Network Meta-Analysis.

Atrial fibrillation (AF) ablation is a frequent procedure used in concomitant cardiac surgery. However, uncertainty still exists concerning the optimal extent of lesion sets. Hence, the objective of this study was to assess the results of various ablation techniques, aiming to offer a reference for clinical decision making. This review is listed in the prospective register of systematic reviews (PROSPERO) under ID CRD42023412785. A comprehensive search was conducted across eight databases (Scopus, Google Scholar, EBSCOHost, PubMed, Medline, Wiley, ProQuest, and Embase) up to 18 April 2023. Studies were critically appraised using the Cochrane Risk of Bias 2.0 for randomized control trials (RCTs) and the Newcastle Ottawa Scale adapted by the Agency for Healthcare Research and Quality (AHRQ) for cohort studies. Forest plots of pooled effect estimates and surface under the cumulative ranking (SUCRA) were used for the analysis. Our analysis included 39 studies and a total of 7207 patients. Both bi-atrial ablation (BAA) and left atrial ablation (LAA) showed similar efficacy in restoring sinus rhythm (SR; BAA (77.9%) > LAA (76.2%) > pulmonary vein isolation (PVI; 66.5%); LAA: OR = 1.08 (CI 0.94-1.23); PVI: OR = 1.36 (CI 1.08-1.70)). However, BAA had higher pacemaker implantation (LAA: OR = 0.51 (CI 0.37-0.71); PVI: OR = 0.52 (CI 0.31-0.86)) and reoperation rates (LAA: OR = 0.71 (CI 0.28-1.45); PVI: OR = 0.31 (CI 0.1-0.64)). PVI had the lowest efficacy in restoring SR and a similar complication rate to LAA, but had the shortest procedure time (Cross-clamp (Xc): PVI (93.38) > LAA (37.36) > BAA (13.89)); Cardiopulmonary bypass (CPB): PVI (93.93) > LAA (56.04) > BAA (0.03)). We suggest that LAA is the best surgical technique for AF ablation due to its comparable effectiveness in restoring SR, its lower rate of pacemaker requirement, and its lower reoperation rate compared to BAA. Furthermore, LAA ranks as the second-fastest procedure after PVI, with a similar CPB time.

Pulsed-field ablation: analysis of a new ablation technique for atrial fibrillation. A single centre experience

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Pulsed-field ablation (PFA) is a new non-thermal, tissue-specific ablation technique. Through the application of a local electric field, it is possible to induce a selective electroporation of cardiomyocytes membranes, resulting in myocytic apoptosis and sparing of non-myocardial structures (nerves, connective tissue, esophagus, vessels). Purpose A new PFA system for atrial fibrillation (AF) ablation has recently been introduced in our hospital. The aim of this retrospective review is to share the initial results of our experience in terms of acute efficacy and safety. Methods A total of 41 adult patients suitable for AF percutaneous ablation underwent PFA between April and November 2022 in our Institute. PFA system consisted of a current generator, a deflectable sheath and a multielectrode PFA catheter. Once inside the left atrium (LA), the PFA catheter was directed to the pulmonary veins (PVs) ostia through an over-the-wire system. Then, 8 electric impulses were applied for each PV to achieve electrical isolation; in some cases, applications to the posterior left atrium wall (LAPW) were delivered to obtain LAPW isolation (LAPWI). A moderate-to-deep sedation was provided by an anesthesiologist during all the procedures. Acute ablation efficacy was defined as absence of intracavitary signals at the electroanatomic mapping and local capture failure at the pacing maneuvers. Intra and peri-procedural safety was defined as the absence of major complications (pericardial effusion/ tamponade, stroke, vascular complications, death) during the procedure and the hospitalization period. Results Of the 41 patients included, 24 (58.5%) were treated for paroxysmal AF and 17 (41.5%) for persistent AF. In almost all cases (n=40, 97.6%) pulmonary veins isolation (PVI) was performed; in 14 cases (34.1%, almost all persistent AF patients) a LAPWI was performed with the application of a variable number of pulses (mean value = 13). In most of the cases (n=28, 68.3%) an electroanatomic mapping was acquired before and after the ablation. Acute efficacy was observed in all PVI cases (n=40, 100%) and in all LAPWI cases (n=14, 100%). No periprocedural major complications were observed (n=0, 0%). Conclusions PFA is a promising ablation technique capable of inducing selective myocytic apoptosis through electroporation, causing a thick damage across the muscle with no injury of other tissues, and could become a game changer in electrophysiology in the next future. Our initial data report a combination of ease of use and high efficacy and safety profiles.

Best Practice Guide for Cryoballoon Ablation in Atrial Fibrillation: The Compilation Experience of More than 1000 Procedures

Nowadays, the cryoballoon (CB) constitutes an established alternative to radio frequency (RF) ablation for pulmonary vein isolation (PVI), which offers the possibility to isolate the PVs with a single application. Since the introduction of the second-generation CB, we prospectively collected our data to optimize the procedure on >1000 consecutive patients who underwent CB PVI performed in our center. It is expected that subsequent guidelines will suggest first-line PVI through CB in patients with paroxysmal AF with a class I indication. Indeed, in the long-term follow-up (36 months) of the EARLY-AF trial, CB had a lower incidence of persistent atrial fibrillation episodes compared to the anti-arrhythmic drugs group. We now review the current best practices in an effort to drive consistent outcomes and minimize complications. PV isolation through CB is the most studied single-shot technique for atrial fibrillation ablation, having shown the potential to alter the natural history of the arrhythmia. Several procedural tips and tricks can improve procedural flow and effectiveness. In the present article we provided not only technical details but measurable biophysical parameters that can reliably guide the operator into achieving the best outcome for his patients.

Successful 4-Year Outcome Following Convergent Ablation for Longstanding Persistent Atrial Fibrillation in an Octogenarian – Novel Therapy for an Old Condition in The Very Elderly

The most common age range for atrial fibrillation (AF) prevalence over the coming decades will potentially be in those over 75 years old. However, despite widespread recognition of the strong association between AF burden and age, the elderly are under-represented within trials evaluating invasive rhythm control strategies. We report the outcomes of a gentleman in his late eighties that underwent Convergent hybrid ablation for highly symptomatic and longstanding persistent AF. Now four years later and into his nineties, he remains in sinus rhythm and enjoys good cardiac health without the need for anti-arrhythmic drugs or further intervention. To our knowledge, this case report is the oldest patient to have successfully undergone Convergent ablation with enduring sinus rhythm with long-term follow-up, despite significant risk factors for AF recurrence. As the overall population ages, the emergence of this minimally invasive multidisciplinary ablation technique for AF may offer to similar patients benefits over percutaneous ablation strategies alone.

Advances in Cardiac Electrophysiology.

Despite the global COVID-19 pandemic, during the past 2 years, there have been numerous advances in our understanding of arrhythmia mechanisms and diagnosis and in new therapies. We increased our understanding of risk factors and mechanisms of atrial arrhythmias, the prediction of atrial arrhythmias, response to treatment, and outcomes using machine learning and artificial intelligence. There have been new technologies and techniques for atrial fibrillation ablation, including pulsed field ablation. There have been new randomized trials in atrial fibrillation ablation, giving insight about rhythm control, and long-term outcomes. There have been advances in our understanding of treatment of inherited disorders such as catecholaminergic polymorphic ventricular tachycardia. We have gained new insights into the recurrence of ventricular arrhythmias in the setting of various conditions such as myocarditis and inherited cardiomyopathic disorders. Novel computational approaches may help predict occurrence of ventricular arrhythmias and localize arrhythmias to guide ablation. There are further advances in our understanding of noninvasive radiotherapy. We have increased our understanding of the role of His bundle pacing and left bundle branch area pacing to maintain synchronous ventricular activation. There have also been significant advances in the defibrillators, cardiac resynchronization therapy, remote monitoring, and infection prevention. There have been advances in our understanding of the pathways and mechanisms involved in atrial and ventricular arrhythmogenesis.

Successful 4-Year Outcome Following Convergent Ablation for Longstanding Persistent Atrial Fibrillation in an Octogenarian – Novel Therapy for an Old Condition in the Very Elderly

The most common age range for Atrial Fibrillation (AF) prevalence over the coming decades will potentially be in those over 75 years old. However, despite widespread recognition of the strong association between AF burden and age, the elderly are under-represented within trials evaluating invasive rhythm control strategies. We report the outcomes of a gentleman in his late eighties that underwent Convergent hybrid ablation for highly symptomatic and longstanding persistent AF. Now four years later and into his nineties, he remains in sinus rhythm and enjoys good cardiac health without the need for anti-arrhythmic drugs or further intervention. To our knowledge, this case report is the oldest patient to have successfully undergone Convergent ablation with enduring sinus rhythm with long-term follow-up, despite significant risk factors for AF recurrence. As the overall population ages, the emergence of this minimally invasive multidisciplinary ablation technique for AF may offer to similar patients benefits over percutaneous ablation strategies alone.

PO-710-04 CONTEMPORARY PREVALENCE AND PREDICTORS OF INTACT PULMONARY VEIN ISOLATION IN PATIENTS UNDERGOING REPEAT ATRIAL FIBRILLATION ABLATION

Pulmonary vein isolation (PVI) is the primary goal of atrial fibrillation (AF) ablation. Prior studies have noted a 50-95% prevalence of pulmonary vein (PV) reconnection at the time of repeat ablation. However, the prevalence of PV reconnection with contemporary AF ablation techniques, including high frequency jet ventilation, is unknown. Furthermore, there is an incomplete understanding of predictors of intact PVI at the time of repeat ablation. To assess the prevalence of PV reconnection in a contemporary cohort utilizing jet ventilation, contact force catheters, and adenosine testing for dormant conduction, and identify patient characteristics and ablation techniques that predict PVI at time of repeat ablation. We reviewed 615 consecutive radiofrequency AF ablations from 2013-2019 at an academic medical center performed by a single operator. There were 121 unique patients who underwent a de novo AF ablation followed by a repeat AF ablation. We evaluated clinical and previous procedural characteristics to identify predictors of PVI at the time of repeat ablation, using logistic regression models. Of the 121 patients, 42.1% were female, average age was 64.5 years, and BMI 31. At the time of repeat ablation, 57% (n=69) had intact prior PVI. Baseline characteristics of patients with intact PVI and reconnected PVI were similar, including age (64 years and 65 years; p=0.75), left atrial diameter (4.13 cm and 4.39 cm; p=0.09), left ventricular ejection fraction (54.5 % and 55.4%; p = 0.38), and time to first atrial fibrillation recurrence (237 days v. 344 days, p=0.28). The only significant clinical predictor of intact PVI was the pre-procedure diagnosis of atypical atrial flutter (20.3 % v. 3.8%, p=0.02) (Figure 1). In multivariate analysis, prior mitral line ablation (OR 8.93, 95%CI [3.65, 21.87]: p <0.01) and first pass isolation of right pulmonary vein during the index AF ablation (OR 2.59, 95% CI [1.09, 6.12]: p = 0.03) strongly predicted intact PVI at the time of repeat AF ablation. With contemporary techniques, PVI reconnection is seen in 43% of patients at the time of repeat AF ablation. History of atypical flutter, prior mitral line ablation, and first pass isolation of the right PVs were significant predictors for intact PVI.

Safety aspects of very high power very short duration atrial fibrillation ablation using a modified radiofrequency RF-generator: Single-center experience.

High power short duration (HPSD) ablation proved to be an effective and safe ablation technique for atrial fibrillation (AF). In former case series, a significant amount of postablation coagulation at the catheter tip as well as silent cerebral lesions (SCL) in postprocedural cerebral magnetic resonance (cMRI) have been identified in patients undergoing de-novo AF ablations with very high power 90 W short duration (vHPvSD) ablations using the QDot ablation catheter in combination with a novel RF generator (nGEN, Biosense Webster). Therefore, the RF generator software has been recently modified. Consecutive patients undergoing a first AF ablation including pulmonary vein isolation (PVI) with vHPvSD (90 W, with a predefined ablation time of 3 s at posterior left atrium (LA) wall sites and 4 s at other ablation sites) using the QDOT Micro ablation catheter (Biosense Webster) in conjunction with the technically modified nGEN RF generator (software V1c; Biosense Webster) were included. Procedural characteristics including first-pass isolation per pulmonary vein (PV) pair and early reconnection location within the 30-minwaiting period were recorded. In all patients postablation endoscopy to document any thermal esophageal injury (EDEL) and in eligible patients a cMRI to detect silent cerebral events (SCEs)/lesionswere performed. All acute procedure-related complications were recorded during the time until hospital discharge. Furthermore, short-term and midterm success after 3 and 6-12 months of follow-up was investigated. In total, 34 consecutive patients (67 ± 9 years; 62% male; 68% paroxysmal AF) were included. First-pass isolation of all PVs was achieved in 6/34 (18%) patients. First-pass isolation was seen in 37/68 (54%) of PV pairs. Early reconnection occurred in 11 (32%) patients (including reconnections at posterior LA wall sites n = 6 and at nonposterior sites n = 5). No patient had an EDEL (0%). In 6/23 (26%) patients undergoing postablation cerebral MRI SCEs were identified. In six patients, coagulation on the catheter tip was detected at the end of the procedure. No further peri- or postprocedural complications were detected. Early AF recurrence before discharge was seen in 1/34 (3%) of the patients included in this study. Within 3 months 10/34 (29%) revealed AF recurrence during blanking period. After a mean follow-up of 7 months, 31/34 (88%) patients revealed sinus rhythm. AF ablation using 90 W vHPvSD with a specialized ablation catheter in conjunction with a recently modified RF generator was associated with no EDEL in the whole study cohort and 26% SCEs in a subgroup of patients undergoing acute postablation cerebral MRI. Accordingly, to our previously published results, a relevant number of catheter tip coagulations was identified in this patient cohort even after modifications of the RF generator. The vHPvSD ablation technique using the present and the previous generator seems to be associated with a very low rate of esophageal injury. However, the recently revised generator software also produced a relevant number of catheter tip coagulum formation and SCEs.

Single ring isolation for atrial fibrillation ablation: Impact of the learning curve.

Although single ring isolation is an accepted strategy for undertaking pulmonary vein (PV) and posterior wall isolation (PWI) during atrial fibrillation (AF) ablation, the learning curve associated with this technique as well as procedural and clinical success rates have not been widely reported. Prospectively collected data from 250 consecutive patients undergoing de novo AF ablation using single ring isolation. PWI was achieved in 212 patients (84.8%) and PV isolation without PWI was achieved in 37 patients (14.4%). Thirty-one cases (12.4%) demonstrated inferior line sparing where PWI was achieved without a continuous posterior wall inferior line. A learning curve was observed, with higher rates of PWI (98% last 50 vs. 82% first 50 cases, p = .016), higher rates of inferior line sparing (20% last 50 vs. 8% first 50 cases, p = .071) and lower ablation times (43.8 min (interquartile range [IQR]: 34.6-57.0 min) last 50 versus. 96.5 min (IQR: 80.8-115.8 min) first 50 cases; p < .001). Three (1.3%) major procedure-related complications were observed. Twelve-month, single-procedure freedom from atrial arrhythmia without drugs was 70.5% (95% confidence interval [CI]: 61.5%-77.7%) and 60.0% (95% CI: 50.2%-68.4%) for paroxysmal and persistent/longstanding persistent AF. Twelve-month multi-procedure freedom from atrial arrhythmia was 92.2% (95%CI: 85.6%-95.9%) and 85.6% (95%CI: 77.2%-91.0%) for paroxysmal and persistent/longstanding persistent AF. Employing a single ring isolation approach, PWI can be achieved in most cases. There is a substantial learning curve with higher rates of PWI, reduced ablation times, and higher rates of inferior line sparing as procedural experience grows. Long-term freedom from arrhythmia is comparable to other AF ablation techniques.

New technique for atrial fibrillation ablation

Sarah Jane Palmer discusses the latest research in technology.

Concomitant atrial fibrillation ablation in patients undergoing coronary artery bypass and cardiac valve surgery.

Surgical ablation of atrial fibrillation (AF) in conjunction with other cardiac surgery is now a class I guideline recommendation. Multiple studies have demonstrated that the concomitant surgical ablation of AF can be performed safely and effectively during valve and coronary artery bypass grafting (CABG) resulting in a return to sinus rhythm postoperatively and improved long-term results. However, the surgical ablation of AF at the time of other cardiac surgery is performed less often than it should be, especially in patients undergoing CABG and aortic valve surgery. Randomized-controlled trials designed to determine the effect of treating AF concomitantly with other cardiac surgical procedures have lacked long-term follow up, but multiple, large observational studies have demonstrated an improved quality of life, a decrease in long-term strokes, and improved late survival in patients who undergo AF ablation. However, the potential survival benefit of concomitant AF ablation was not addressed by either the Society of Thoracic Surgery or American Association for Thoracic Surgery guideline committees. Left atrial appendage closure is an important part of the surgical ablation of AF as it significantly reduces the long-term risk of stroke following cardiac surgery and improves the success of AF treatment. In this study, we update the electrophysiology and surgical community on the recommended surgical techniques for AF ablation and its effect on perioperative morbidity, perioperative mortality, as well as its long-term effects on stroke, quality of life, and survival.

Ablation Approaches and Imaging Modalities to Lower Risk of Atrioesophageal Injury During Catheter Ablation for Atrial Fibrillation

Atrioesophageal fistula (AEF) is a rare yet catastrophic complication of atrial fibrillation (AF) ablation. Limited data exists on measures to prevent AEF. This review focuses on AF ablation approaches, esophageal protective strategies, and imaging modalities that can be utilized to reduce the risk of AEF. AEF has been reported to occur in less than 0.1% of AF ablation cases. Left untreated, it is associated with 100% mortality. Diagnosing AEF requires a high index of suspicion as symptoms are usually nonspecific. Several AF ablation techniques might reduce the risk of esophageal thermal injury (ETI): high-power short-duration radiofrequency ablation, implementation of time-to-isolation ablation strategy with cryoablation, and electroporation. Various esophageal protective approaches have been investigated. Although luminal esophageal temperature monitoring is widely used, data on its efficacy is conflicting. Esophageal cooling and esophageal deviation strategies have been shown to be effective in reducing the risk of ETI. Late gadolinium enhancement magnetic resonance imaging (LGE-MRI) is a noninvasive imaging modality that seems to have high sensitivity for detecting and quantifying the degree of ETI. Variable approaches have been reported to reduce the risk of esophageal injury. These approaches focus mainly on modulating ablation parameters and esophageal luminal temperature. Imaging modalities such as LGE-MRI can potentially identify early signs of ETI. Electroporation is a promising ablation technique that exhibits high tissue selectivity and can potentially reduce risk of esophageal injury.

Cryoballoon Pulmonary Vein Isolation and Roof and Posterior Wall Debulking Using Navik 3D™: A New Technique for Atrial Fibrillation Ablation.

The success rates of traditional endocardial ablation techniques for managing atrial fibrillation remain modest. Recently, the performance of posterior wall ablation in conjunction with pulmonary vein (PV) isolation (PVI) has been reported to increase the chance of success following endocardial ablation. We report a systematic approach for the isolation of the PVs and ablation of the left atrial roof and posterior wall using a cryoballoon guided by the novel Navik 3D™ mapping system (APN Health LLC, Waukesha, WI, USA) and offer preliminary data including procedure, fluoroscopy, and cryoablation times for review. Patients (n = 52) aged 63 years ± 10 years with paroxysmal (n = 42), persistent (n = 11), or chronic (n = 2) atrial fibrillation underwent cryoballoon ablation for PVI and/or the left atrial roof, posterior wall, anterior ganglion plexi (GP), or mitral isthmus line. Lesions were accurately delivered to the PVs, left atrial roof, posterior wall, anterior GP, or mitral isthmus line as appropriate. Acute PVI was achieved in 98% of all patients, and eight (15%) required direct current cardioversion to restore sinus rhythm at the end of the procedure. The mean ± standard deviation procedure, fluoroscopy, and cryoballoon ablation times were 149 minutes ± 39 minutes, 33 minutes ± 30 minutes, and 41 minutes ± 14 minutes, respectively. The Navik 3D™ mapping system is believed to be the only available mapping system that allows for the visualization and location of the cryoballoon in three dimensions, enabling the operator to deliver contiguous, overlapping lesions on the roof and posterior wall of the left atrium. It also facilitates precise measurement of the distance between the esophageal temperature probe and the cryoballoon, thereby helping to avoid freezing damage to the esophagus.

P1912Incidence of silent cerebral thromboembolism in catheter ablation for atrial fibrillation under the use of DOAC: Comparison of cryoballoon versus radiofrequency ablation system

Abstract Background Silent cerebral thromboembolism (CE) in catheter ablation for atrial fibrillation (AF) is not rare. Prior our study has reported lower incidence of silent CE in AF radiofrequency (RF) ablation using irrigated-tip catheter than conventional 4 or 8mm-tip catheter. In addition, the incidence of silent CE in AF ablation under direct oral anticoagulant (DOAC) was equivalent to continuous therapeutic warfarin. Recently pulmonary vein isolation (PVI) using cryoballoon (CB) has emerged as an alternative technique to RF ablation because some studies suggested that the efficacy for PVI by CB was equivalent to RF. However, incidence of silent CE in CB ablation under the use of DOAC is unknown. Objective We aimed to evaluate the incidence new silent CE in AF ablation using CB system compared with irrigated RF system under the use of DOAC. Methods 322 consecutive patients with paroxysmal or persistent AF (155 using CB system, 167 using RF system) who underwent the first AF ablation were taking DOAC more than one month prior to the procedure. Throughout AF ablation procedure, heparin was administered to maintain activated clotting time (ACT) between 300 and 400 seconds. Head MRI was performed in all patients within 24 hours after the procedure. Results In 14 (9.0%) patients using CB and in 20 (12.0%) patients using RF, head MRI showed new embolic lesions without neurological symptom (P=0.469). Although the amount of heparin during the procedure in group CB was significantly less than in group RF (16134±3125 U vs. 18689±5222 U; P&lt;0.0001), amount of heparin per hour in group CB was more than in group RF (8335±1955 U/h vs. 6143±1918 U/h; P&lt;0.0001) because procedure time in group CB was shorter than in group RF (121.3±34.1 min vs. 189.5±47.4 min; P&lt;0.0001). Mean ACT in both groups was maintained high level (3367±25.3 sec. vs. 338.6±23.5 sec.; P=0.479). In univariate analysis, minimum ACT during procedure, as before puncture of interatrial septum, were significantly correlated with the incidence of silent CE (P=0.027). Conclusions The incidence of silent CE in AF ablation using CB system was lower than RF system, although it was not a significant difference between different ablation techniques for AF. In AF ablation, the use of CB may be preferred rather than RF as ablation system in regard to risk reduction of thromboembolic complications.

Silent cerebral infarcts following pulmonary vein isolation with different atrial fibrillation ablation techniques - incidence and risk factors.

IntroductionSilent cerebral infarcts (SCIs) detected by diffusion-weighted magnetic resonance (DW-MRI) following atrial fibrillation (AF) ablation have been reported, with the incidence of 1–38%. We aimed to compare the incidence of SCIs following AF ablation with four different technologies and analyze the risk factors.Material and methodsA total of 104 patients (mean age: 59.9 ±9.5 years, 68 males) with symptomatic AF, referred for ablation, were included in the study. The AF ablation was performed with irrigated radiofrequency point-by-point technique (RF group) in 24 patients, and with 3 different single-shot techniques: phased-RF (PVAC) in 46, second-generation cryoballoon (CB) in 24 and irrigated multipolar RF catheter (nMARQ) in 10 patients. In all patients DW-MRI was performed pre- and post-procedurally to evaluate the incidence of SCIs. Procedural parameters, complication rate and post-procedural SCI incidence were compared between the groups.ResultsProcedure (167.1 vs. 110.5 vs. 106.0 vs. 141.5 min, p < 0.001), fluoroscopy (22.7 vs. 15.9 vs. 16.3 vs. 15.3 min, p = 0.048) and LA dwell (101.5 vs. 53.9 vs. 56.0 vs. 97.0 min, p < 0.001) times compared respectively between RF, PVAC, CB and nMARQ groups were significantly shorter with single-shot techniques. The number of new-onset SCIs was 4/24 (16.7%) in RF, 7/46 (15.2%) in PVAC, 1/24 (4.2%) in CB and 1/10 (10%) in the nMARQ group. Univariate analysis identified procedure duration (p = 0.02), lower LV ejection fraction (p = 0.03), persistent form of arrhythmia (p = 0.007) and intraprocedural cardioversion (p = 0.002) as risk factors of new-onset SCIs.ConclusionsSilent cerebral infarcts can be detected following AF ablation regardless of the technology used. Prolonged procedure time, lower ejection fraction, persistent form of arrhythmia and intraprocedural cardioversion increase the risk of SCIs.

Management of Atrial Fibrillation in Patients Undergoing Coronary Artery Bypass Grafting: Review of the Literature.

Untreated atrial fibrillation is associated with an increased risk of all-cause mortality and morbidity. Despite the current guidelines recommending surgical ablation of atrial fibrillation at the time of coronary artery bypass surgery, most patients with concomitant atrial fibrillation and coronary artery disease do not receive surgical ablation for their atrial fibrillation. This review reports the efficacy of different surgical ablation techniques used for the treatment of atrial fibrillation during coronary artery bypass. PubMed was systematically searched for studies reporting outcomes of concomitant surgical ablation in coronary artery bypass patients between January 2002 and March 2018. Data were independently extracted and analyzed by two investigators. Twenty-four studies were included. Twelve studies exclusively reported outcomes of surgical ablation in patients undergoing coronary artery bypass, whereas the remaining 12 reported outcomes of concomitant cardiac surgery with subgroup analysis. Only four studies performed the concomitant Cox-Maze procedure. Freedom from atrial tachyarrhythmia was reported as high as 98% at 1 year and 76% at 5 years with Cox-Maze procedure, whereas lesser lesion sets had more variable outcomes, ranging from 35% to 93%. In most studies, the addition of surgical ablation was not associated with increased morbidity and mortality. Although the Cox-Maze procedure had the greatest short- and long-term success rates, most studies comprising the evidence documenting the safety and efficacy of adding surgical ablation were of low or moderate quality. There was a great deal of heterogeneity among study populations, follow-up times, methods, and definition of failure. To establish a consensus regarding a surgical ablation technique for atrial fibrillation in coronary artery bypass population, larger multicenter randomized controlled studies need to be designed.