Importance of non–pulmonary vein triggers ablation to achieve long-term freedom from paroxysmal atrial fibrillation in patients with low ejection fraction

Embryological Classification of Arrhythmogenic Triggers Initiating Atrial Fibrillation

BACKGROUND

Atrial fibrillation (AF) is a prevalent multifactorial arrhythmia associated with specific single-nucleotide polymorphisms (SNPs). Pulmonary vein (PV) isolation is an established treatment for AF; however, recurrence risk remains caused by AF triggers beyond the PVs. Understanding the embryological origins of these triggers could improve treatment outcomes.

OBJECTIVES

This study aimed to investigate the association between embryologically categorized AF triggers, clinical and genetic backgrounds, and postablation prognosis.

METHODS

In cohort 1, comprising 3,067 patients with AF undergoing PV isolation, the clinical characteristics and outcomes were analyzed. Among them, 815 patients underwent genetic analysis using AF-associated SNPs (cohort 2). Patients were delineated based on the developmental origin of the AF triggers: common PV, sinus venosus (SV), and primitive atrium (PA).

RESULTS

SV-origin extra-PV AF triggers occurred in 20.3% (n = 622) of patients, whereas PA-origin triggers occurred in 11.9% (n = 365) of patients in cohort 1. Multivariate analysis of cohort 2 revealed that female sex, lower body mass index, absence of hypertension, rs2634073 near PITX2, and rs6584555 in NEURL1 were associated with SV-AF, whereas nonparoxysmal AF and rs2634073 near PITX2 were predictors of PA-AF. The PA group had a significantly higher arrhythmia recurrence rate after repeated procedures than the common PV (HR: 1.75; 95% CI: 1.34-2.29; P < 0.001) and SV-AF (HR: 1.31; 95% CI: 1.19-1.45; P < 0.001) groups with more de novo AF triggers. However, the incidence of adverse events did not differ significantly among the 3 groups.

CONCLUSIONS

SV-derived AF triggers may have hereditary factors with a favorable postablation prognosis, whereas PA-derived triggers are linked to AF persistence and poor ablation response. Variants near PITX2 may play a pivotal role in extra-PV triggers.

Impact of residual induction number of non-pulmonary vein foci on the 2-year outcomes in patients with paroxysmal atrial fibrillation

BACKGROUND

Residual non-pulmonary vein (PV) foci are significantly associated with atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI). However, we previously reported among patients with non-PV foci induced only once, none experienced AF recurrence. Thus, we aimed to investigate the correlation between the residual induction number of non-PV foci and ablation outcome in paroxysmal AF patients.

METHODS AND RESULTS

We investigated 55 paroxysmal AF patients with residual non-PV foci after PVI and ablation of non-PV-foci. Study patients were classified into the residual one-time induction of non-PV foci (residual OTI-nPVF) group (n = 23) and residual repeatedly induced non-PV foci (residual RI-nPVF) group (n = 32). Furthermore, the residual RI-nPVF group was divided into the low inducibility group (n = 10) and high inducibility group (n = 22) according to the presence or absence of non-PV foci provoked by two sets of drug induction tests (non-PV foci inducibility). In addition, the latter was divided into the ablation group (n = 14) or observation group (n = 8). The 2-year AF recurrence-free rate in the residual RI-nPVF group was significantly lower compared to the residual OTI-nPVF group (53% vs. 90%, p = 0.018). There was no significant difference of the 2-year AF recurrence-free rates in the inducibility of non-PV foci (p = 0.913) and the presence or absence of ablation (p = 0.812) in the residual RI-nPVF group.

CONCLUSIONS

Among paroxysmal AF patients, the presence of residual RI-nPVF was associated with higher AF recurrence compared to residual OTI-nPVF. Furthermore, within residual RI-nPVF subgroup, non-PV foci inducibility or ablation of some residual RI-nPVF did not affect ablation outcome.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society.

A validation study of the accuracy of the atrial pace map assessed with intracardiac pattern matching: Potential utility of non-pulmonary vein mapping

BACKGROUND

Identification of infrequent nonpulmonary vein trigger premature atrial contractions (PACs) is challenging. We hypothesized that pace mapping (PM) assessed by correlation scores calculated by an intracardiac pattern matching (ICPM) module was useful for locating PAC origins, and conducted a validation study to assess the accuracy of ICPM-guided PM.

METHODS

Analyzed were 30 patients with atrial fibrillation. After pulmonary vein isolation, atrial pacing was performed at one or two of four sites on the anterior and posterior aspects of the left atrium (LA, n = 10/10), LA septum (n = 10), and lateral RA (n = 10), which was arbitrarily determined as PAC. The intracardiac activation obtained from each pacing was set as an ICPM reference consisting of six CS unipolar electrograms (CS group) or six CS unipolar electrograms and four RA electrograms (CS-RA group).

RESULTS

The PM was performed at 193 ± 107 sites for each reference pacing site. All reference pacing sites corresponded to sites where the maximal ICPM correlation score was obtained. Sites with a correlation score ≥98% were rarely obtained in the CS-RA than CS group (33% vs. 55%, P = .04), but those ≥95% were similarly obtained between the two groups (93% vs. 88%, P = .71), and those ≥90% were obtained in all. The surface areas with correlation scores ≥98% (0[0,10] vs. 10[0,35] mm2, P = .02), ≥95% (10[10,30] vs. 50[10,180] mm2, P = .002) and ≥90% (60[30,100] vs. 170[100,560] mm2, P = .0002) were smaller in the CS-RA than CS group.

CONCLUSIONS

ICPM-guided PM was useful for identifying the reference pacing sites. Combined use of RA and CS electrograms may improve the mapping quality.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society (HRS), the Asia Pacific HRS, and the Latin American HRS.

2023 Cardiac Society of Australia and New Zealand Expert Position Statement on Catheter and Surgical Ablation for Atrial Fibrillation

Catheter ablation for atrial fibrillation (AF) has increased exponentially in many developed countries, including Australia and New Zealand. This Expert Position Statement on Catheter and Surgical Ablation for Atrial Fibrillation from the Cardiac Society of Australia and New Zealand (CSANZ) recognises healthcare factors, expertise and expenditure relevant to the Australian and New Zealand healthcare environments including considerations of potential implications for First Nations Peoples. The statement is cognisant of international advice but tailored to local conditions and populations, and is intended to be used by electrophysiologists, cardiologists and general physicians across all disciplines caring for patients with AF. They are also intended to provide guidance to healthcare facilities seeking to establish or maintain catheter ablation for AF.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society .

Antithrombotic Therapy for Patients Undergoing Cardiac Electrophysiological and Interventional Procedures: JACC State-of-the-Art Review

Electrophysiological and interventional procedures have been increasingly used to reduce morbidity and mortality in patients experiencing cardiovascular diseases. Although antithrombotic therapies are critical to reduce the risk of stroke or other thromboembolic events, they can nonetheless increase the bleeding hazard. This is even more true in an aging population undergoing cardiac procedures in which the combination of oral anticoagulants and antiplatelet therapies would further increase the hemorrhagic risk. Hence, the timing, dose, and combination of antithrombotic therapies should be carefully chosen in each case. However, the maze of society guidelines and consensus documents published so far have progressively led to a hazier scenario in this setting. Aim of this review is to provide-in a single document-a quick, evidenced-based practical summary of the antithrombotic approaches used in different cardiac electrophysiology and interventional procedures to guide the busy clinician and the cardiac proceduralist in their everyday practice.

Cryoballoon ablation of non-PV triggers in persistent atrial fibrillation

Cryoballoon-based catheter ablation has emerged as an efficacious and safe therapeutic intervention for patients with paroxysmal atrial fibrillation (PAF). PAF is primarily associated with the triggers in the pulmonary vein (PV). However, persistent atrial fibrillation (PeAF) is a complex condition that involves changes in the atrial substrate and the presence of non-PV triggers. Therefore, a comprehensive treatment approach is necessary for patients with PeAF. Utilizing a 3D electroanatomical map, the radiofrequency-based ablation technique adeptly identifies and targets the atrial substrate and non-PV triggers. On the other hand, the cryoballoon-based AF ablation was initially designed for PV isolation. However, its single-shot feature makes it a great choice for electrophysiologists looking to address non-PV triggers. It is possible to target the left atrial appendage (LAA), superior vena cava (SVC), left atrial roof, and posterior wall using the apparatus's unique configuration and ablation abilities. This review focuses on the increasing literature regarding cryoballoon-based methods for non-PV trigger ablation. Specifically, it delves into the technical procedures used to isolate the LAA, SVC, and ablate the left atrial roof and posterior wall.

Comparison of advanced generation cryoballoon ablation and ablation index-guided pulmonary vein isolation with non-pulmonary vein trigger induction test and additional ablation in paroxysmal atrial fibrillation

BACKGROUND

An ablation index (AI)-guided pulmonary vein isolation (PVI) or 2nd generation cryoballoon (CB)-PVI has been shown to reduce the atrial fibrillation (AF) burden by 99% despite the absence of ablation of non-pulmonary vein (PV) triggers in patients with paroxysmal AF. The purpose of this study was to investigate the effects of PVI alone strategy using 2nd generation CB compared with AI-guided PVI with an additional induction test and subsequent AF trigger ablation.

METHODS AND RESULTS

We investigated 223 patients with symptomatic paroxysmal AF who underwent an initial PVI between August 2018 and August 2020. The study patients were divided into 2 groups: CB-PVI without an induction test (CB-PVI alone group, n = 82) and AI-guided PVI with an induction test and subsequent additional ablation of non-PV triggers (AI-PVI plus group, n = 141). In the AI-PVI plus group, a total of 62 non-PV triggers were induced in 38 patients, and non-PV triggers in 22 patients were completely ablated. The procedure time and left atrium dwell time were significantly shorter in the CB-PVI alone group than AI-PVI plus group. There were no significant differences in the incidence of procedural complications between the 2 groups (P = 0.650). The AF free survival rate in the CB-PVI alone group and AI-PVI plus group was 80% vs. 80% at 24 months (P = 0.969).

CONCLUSIONS

An PVI alone strategy using advanced generation CB did not differ in the clinical outcomes compared with an AI-guided PVI strategy with an induction test and subsequent ablation of non-PV triggers in the patients with paroxysmal AF.

Risk factors for atrial arrhythmia recurrence after atrial arrhythmia surgery with pulmonary valve replacement

Objectives

Atrial arrhythmias are a significant cause of late morbidity and mortality in patients after tetralogy of Fallot repair. However, reports on their recurrence following atrial arrhythmia surgery are limited. We aimed to identify the risk factors for atrial arrhythmia recurrence after pulmonary valve replacement (PVR) and arrhythmia surgery.

Methods

We reviewed 74 patients with repaired tetralogy of Fallot who underwent PVR for pulmonary insufficiency at our hospital between 2003 and 2021. Twenty-two patients (mean age, 39 years) underwent PVR and atrial arrhythmia surgery. A modified Cox-maze III was performed in 6 patients with chronic atrial fibrillation, and a right-sided maze was performed in 12 with paroxysmal atrial fibrillation, 3 with atrial flutter, and 1 with atrial tachycardia. Atrial arrhythmia recurrence was defined as any documented sustained atrial tachyarrhythmia requiring intervention. The influence of preoperative parameters on recurrence was assessed with the Cox proportional-hazards model.

Results

The median follow-up period was 9.2 years (interquartile range, 4.5-12.4). Cardiac death and redo-PVR due to prosthetic valve dysfunction were not observed. Eleven patients had atrial arrhythmia recurrence after discharge. Atrial arrhythmia recurrence-free rates were 68% at 5 years and 51% at 10 years after PVR and arrhythmia surgery. Multivariable analysis revealed that right atrial volume index (hazard ratio, 1.04; 95% confidence interval, 1.01-1.08, P = .009) was a significant risk factor for atrial arrhythmia recurrence after arrhythmia surgery and PVR.

Conclusions

Preoperative right atrial volume index was associated with atrial arrhythmia recurrence, which may assist in planning the timing of atrial arrhythmia surgery and PVR.

Catheter Ablation for Atrial Fibrillation in Structural Heart Disease: A Review

Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice. Patients with structural heart disease (SHD) are at an increased risk of developing this arrhythmia and are particularly susceptible to the deleterious hemodynamic effects it carries. In the last two decades, catheter ablation (CA) has emerged as a valuable strategy for rhythm control and is currently part of the standard care for symptomatic relief in patients with AF. Growing evidence suggests that CA of AF may have potential benefits that extend beyond symptoms. In this review, we summarize the current knowledge of this intervention on SHD patients.

Feasibility of Linear Irreversible Electroporation Ablation in the Coronary Sinus

INTRODUCTION

Previous studies demonstrated that the coronary sinus (CS) is an important target for ablation in persistent atrial fibrillation. However, radiofrequency ablation in the CS is associated with coronary vessel damage and tamponade. Animal data suggest irreversible electroporation (IRE) ablation can be a safe ablation modality in vicinity of coronary arteries. We investigated the feasibility of IRE in the CS in a porcine model.

METHODS

Ablation and pacing was performed in the CS in six pigs (weight 60-75 kg) using a modified 9-French steerable linear hexapolar Tip-Versatile Ablation Catheter. Pacing maneuvers were performed from distal to proximal segments of the CS to assess atrial capture thresholds before and after IRE application. IRE ablations were performed with 100 J IRE pulses. After 3-week survival animals were euthanized and histological sections from the CS were analyzed.

RESULTS

A total of 27 IRE applications in six animals were performed. Mean peak voltage was 1509 ± 36 V, with a mean peak current of 22.9 ± 1.0 A. No complications occurred during procedure and 3-week survival. At 30 min post ablation 100% isolation was achieved in all animals. At 3 weeks follow-up pacing thresholds were significant higher as compared to baseline. Histological analysis showed transmural ablation lesions in muscular sleeves surrounding the CS.

CONCLUSION

IRE ablation of the musculature along the CS using a multi-electrode catheter is feasible in a porcine model.

Pulsed-field ablation-based pulmonary vein isolation: acute safety, efficacy and short-term follow-up in a multi-center real world scenario

PURPOSE

Pulsed-field ablation (PFA) is a new energy source to achieve pulmonary vein isolation (PVI) by targeted electroporation of cardiomyocytes. Experimental and controlled clinical trial data suggest good efficacy of PFA-based PVI. We aimed to assess efficacy, safety and follow-up of PFA-based PVI in an early adopter routine care setting.

METHODS

Consecutive patients with symptomatic paroxysmal or persistent atrial fibrillation (AF) underwent PVI using the Farawave® PFA ablation catheter in conjunction with three-dimensional mapping at two German high-volume ablation centers. PVI was achieved by applying 8 PFA applications in each PV.

RESULTS

A total of 138 patients undergoing a first PVI (67 ± 12 years, 66% male, 62% persistent AF) were treated. PVI was achieved in all patients by deploying 4563 applications in 546 PVs (8.4 ± 1.0/PV). Disappearance of PV signals after the first application was demonstrated in 544/546 PVs (99.6%). More than eight PFA applications were performed in 29/546 PVs (6%) following adapted catheter positioning or due to reconnection as assessed during remapping. Mean procedure time was 78 ± 22 min including pre- and post PVI high-density voltage mapping. PFA catheter LA dwell-time was 23 ± 9 min. Total fluoroscopy time and dose area product were 16 ± 7 min and 505 [275;747] cGy*cm². One pericardial tamponade (0.7%), one transient ST-elevation (0.7%) and three groin complications (2.2%) occurred. 1-year follow-up showed freedom of arrhythmia in 90% in patients with paroxysmal AF (n = 47) and 60% in patients with persistent AF (n = 82, p = 0.015).

CONCLUSIONS

PFA-based PVI is acutely highly effective and associated with a beneficial safety and low recurrence rate.

Development and Validation of a Risk Nomogram Model for Predicting Recurrence in Patients with Atrial Fibrillation After Radiofrequency Catheter Ablation

Purpose

This study aimed to develop and validate a risk nomogram model for predicting the risk of atrial fibrillation recurrence after radiofrequency catheter ablation.

Patients and Methods

A retrospective observational study was conducted using data from 485 patients with atrial fibrillation who underwent the first radiofrequency ablation in our hospital from January 2018 to June 2021. All patients were randomized into training cohort (70%; n=340) and validation cohort (30%; n=145). Univariate and multivariate logistic regression analyses were used to identify independent risk factors. The predictive nomogram model was established by using R software. The nomogram was developed and evaluated based on differentiation, calibration, and clinical efficacy by concordance statistic (C-statistic), calibration plots, and decision curve analysis (DCA), respectively.

Results

The nomogram was established by four variables including left atrial diameter (OR 1.057, 95% CI 1.010–1.107, P=0.018), left ventricular ejection fraction (OR 0.943, 95% CI 0.905–0.982, P=0.005), type of atrial fibrillation (OR 2.164, 95% CI: 1.262–3.714), and systemic inflammation score (OR 1.905, 95% CI 1.408–2.577). The C-statistic of the nomogram was 0.741 (95% CI: 0.689–0.794) in the training cohort and 0.750 (95% CI: 0.670–0.831) in the validation cohort. The calibration plots showed good agreement between the predictions and observations in the training and validation cohorts. Decision curve analysis and clinical impact curves indicated the clinical utility of the predictive nomogram.

Conclusion

The nomogram model has good discrimination and accuracy, which can screen high-risk groups intuitively and individually, and has a certain predictive value for atrial fibrillation recurrence in patients after radiofrequency ablation.

Provocation and localization of atrial ectopy in patients with atrial septal defects

Background

Atrial fibrillation (AF) is associated with atrial septal defects (ASDs), but the mechanism of arrhythmia in these patients is poorly understood. We hypothesised that right-sided atrial ectopy may predominate in this cohort. Here, we aimed to localise the origin of spontaneous and provoked atrial ectopy in ASD patients.

Methods

Following invasive calibration of P-wave axes, 24-h Holter monitoring was used to determine the chamber of origin of spontaneous atrial ectopy. Simultaneous electrogram recording from multiple intra-cardiac catheters was used to determine the chamber of origin of isoprenaline-provoked ectopy. Comparison was made to a group of non-congenital heart disease AF patients.

Results

Amongst ASD patients, a right-sided origin for spontaneous atrial ectopy was significantly more prevalent than a left-sided origin (24/30 patients with right-sided ectopy vs. 14/30 with left-sided ectopy, P = 0.015). Amongst AF patients, there was no difference in the prevalence of spontaneous right vs. left-sided ectopy. For isoprenaline-provoked ectopy, there was no significant difference in the proportions of patients with right-sided or left-sided ectopy in either group.

Conclusions

When spontaneous atrial ectopy occurs in ASD patients, it is significantly more prevalent from a right-sided than left-sided origin. Isoprenaline infusion did not reveal the predilection for right-sided ectopy during electrophysiology study.

Outcomes of atrial fibrillation ablation in patients with or without silent pulmonary veins from prior ablation procedure

INTRODUCTION

Pulmonary venous (PV) electrical recovery underlies most arrhythmia recurrences after atrial fibrillation (AF) ablation. Little is known about procedural profiles and outcomes of patients with electrically silent PVs upon redo ablation for AF.

METHODS

In a prospectively maintained registry, we enrolled 838 consecutive patients (2013-2016) undergoing redo ablation procedures. Ablation procedures targeted the PVs, the PV antra, and non-PV sites at operators' discretion. Procedural profiles and clinical outcomes were assessed. The primary outcome was freedom from AF after a 3-month blanking period. The secondary outcome was improvement in quality of life.

RESULTS

Most patients undergoing redo AF ablation (n = 684, 82%) had PV reconnection while the remaining 154 (18%) had electrically silent PVs. Patients with recurrent AF and electrically silent PVs were older (66 vs. 64 years, p = .02), had more prior ablation procedures (median 2 IQR 1-3 vs 1 IQR 1-2 p = .001), were more likely to have non-paroxysmal AF (62% vs. 49%, p = .004) and atrial flutter (48% vs. 29%, p = .001) and had significantly larger left atrial volumes (89 vs. 81 ml, p = .003). Patients with silent PVs underwent a more extensive non-PV ablation strategies with antral extension of prior ablation sets in addition to ablation of the roof, appendage, inferior to the right PVs, peri-mitral flutter lines, cavotricuspid isthmus lines and ablation in the coronary sinus. Upon one year of follow-up, patients with electrically silent PVs were less likely to remain free from recurrent atrial arrhythmias (64% vs. 76%, p = .008). Regardless of PV reconnection status, redo ablation resulted in improvement in quality of life.

CONCLUSION

Rhythm control with extensive ablation allowed maintenance of sinus rhythm in about two thirds of patients with silent PVs during redo AF ablation procedures. Regardless of PV reconnection status, redo ablation resulted in improvement in quality of life. This remains a challenging group of patients, highlighting the need to better understand non-PV mediated AF.

Effect of isolation feasibility of non-pulmonary vein foci on efficacy of ablation for atrial fibrillation: comparison of the isolation and focal ablation methods

PURPOSE

Atrial fibrillation (AF) mainly originates from the pulmonary vein (PV). However, some AF triggers originate from other sites, namely non-PV foci, which are related to recurrence after AF ablation. This study aimed to evaluate the effects of isolation feasibility (isolability) of non-PV foci on the efficacy of AF ablation.

METHODS

Overall, 1855 patients with AF (age, 64.6 ± 10.9 years; 82% paroxysmal) underwent PV isolation, followed by induction and ablation of non-PV foci. Among them, 545 (29%) patients had non-PV foci; these patients were categorized into those with isolable non-PV foci (n = 196, 36%) and those with non-isolable non-PV foci (n = 349, 64%).

RESULTS

During a mean follow-up of 31.2 ± 15.6 months, recurrence was higher in the non-isolable group than in the isolable group (34% vs. 19%, P < 0.01). Kaplan-Meier analyses revealed a significantly better 1-year clinical outcome in the isolable group than in the non-isolable group (88.0% vs. 78.4%, P < 0.001; hazard ratio (HR), 0.56; 95% confidence interval (CI), 0.39-0.81). This outcome was not inferior to that of patients without non-PV foci (88.3% vs. 90.8%, P = 0.81). The non-isolable group showed poorer clinical outcomes than patients without non-PV foci (78.4% vs. 90.8%, P < 0.001; HR, 1.37; 95% CI, 1.22-1.53). Cox regression analysis revealed that isolability (HR, 0.56; 95% CI, 0.36-0.89) and unmappability (HR, 2.89; 95% CI, 1.55-5.37) of non-PV foci were significant predictors of arrhythmia recurrence.

CONCLUSION

The isolability of non-PV foci was a significant factor affecting the achievement of better clinical outcomes following AF ablation in patients with non-PV foci.

Innovations in atrial fibrillation ablation

BACKGROUND

Catheter-based ablation to perform pulmonary vein isolation (PVI) has established itself as a mainstay in the rhythm control strategy of atrial fibrillation. This review article aims to provide an overview of recent advances in atrial fibrillation ablation technology.

METHODS

We reviewed the available literature and clinical trials of innovations in atrial fibrillation ablation technologies including ablation catheter designs, alternative energy sources, esophageal protection methods, electroanatomical mapping, and novel ablation targets.

RESULTS

Innovative radiofrequency (RF) catheter designs maximize energy delivery while avoiding overheating associated with conventional catheters. Single-shot balloon catheters in the form of cryoballoons, radiofrequency, and laser balloons have proven effective at producing pulmonary vein isolation and improving procedural efficiency and reproducibility. Pulsed field ablation (PFA) is a highly anticipated novel nonthermal energy source under development, which demonstrates selective ablation of the myocardium, producing durable lesions while also minimizing collateral damage. Innovative devices for esophageal protection including esophageal deviation and cooling devices have been developed to reduce esophageal complications. Improved electroanatomical mapping systems are being developed to help identify additional non-pulmonary triggers, which may benefit from ablation, especially with persistent atrial fibrillation. Lastly, the vein of Marshall alcohol ablation has been recently studied as an adjunct therapy for improving outcomes with catheter ablation for persistent atrial fibrillation.

CONCLUSIONS

Numerous advances have been made in the field of atrial fibrillation ablation in the past decade. While further long-term data is still needed for these novel technologies, they show potential to improve procedural efficacy and safety.

Evaluation of arrhythmogenic foci using a novel automated detection algorithm and isoproterenol in persistent atrial fibrillation

PURPOSE

The CARTOFINDER mapping system analyzes activation patterns using unipolar potentials during atrial fibrillation (AF), where isoproterenol (ISP) is conventionally used to induce non-pulmonary vein (PV) foci and confirm PV arrhythmogenicity. In 20 patients with persistent AF who underwent ablation at our hospital, arrhythmogenic foci were evaluated using both these methods.

METHODS

Before pulmonary vein isolation (PVI), PV and left atrium (LA) were analyzed during AF using CARTOFINDER, and the isolation line was determined based on the results. After PVI, ISP was loaded after return of sinus rhythm and confirmation of the presence of arrhythmogenic foci. The activation site in LA was ablated at the discretion of the surgeon.

RESULTS

Focal activation sites detected by CARTOFINDER correlated with the arrhythmogenic foci induced by ISP in the PVs. The results also showed that a greater number of focal activation sites in the PVs correlated to an increased response to ISP administration. In one patient, it was observed that the focal activation site identified in the PV also coincided with the site of the origin of automaticity induced by ISP after PVI.

CONCLUSION

CARTOFINDER and ISP both reliably determined the presence of arrhythmogenic foci in PV, in patients with persistent AF. Knowledge of the nature of arrhythmogenic foci in non-PV is considered to be a topic for future studies, and further data collection is required.

Beyond pulmonary vein isolation for persistent atrial fibrillation: sequential high-resolution mapping to guide ablation

Purpose

We aimed to evaluate whether outcomes with ablation in persistent (PsAF) and long-standing persistent (LsPsAF) AF can be improved beyond what can be achieved with pulmonary vein isolation (PVI) alone, using individualized mapping to guide ablation.

Methods

We studied 20 pts (15 M, 68 ± 11y) with PsAF (14) or LsPsAF (6) referred for first-time AF ablation. Following antral PVI, individualized mapping (IM) was performed using a high-density mapping catheter stably and fully deployed for 30 s at each of 23 ± 9 sites per patient. Activation data were reviewed, and an ablation strategy designed to intersect areas of focal and rotational activity. Mean follow-up was 429 ± 131 days. The study population was compared to a matched contemporary control cohort (CC) of 20 consecutive patients undergoing conventional ablation.

Results

Despite the IM group having a higher median comorbidities score, 3.5 vs. 2.5 in the CC group, indicating potentially more complex patients and more advanced substrate, cumulative freedom from AF after a single procedure was achieved in 94% of patients in the IM group vs. 75% in the CC group at 1 year and remained the same in both groups at the conclusion of the study (p = 0.02). There was a similar trend in atrial arrhythmia-free survival between both groups (84% vs. 67% at 1 year) that did not reach statistical significance. The procedure duration was longer in the IM group by a median of 31.5 min (p = 0.004).

Conclusions

Individualized mapping to guide AF ablation appears to achieve significantly greater AF-free survival compared to conventional PVI when applied as a primary ablation treatment. The results of this pilot study need to be confirmed in a larger, randomized trial.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10840-021-01115-7.

Adding six short lines on pulmonary vein isolation circumferences reduces recurrence of paroxysmal atrial fibrillation: Results from a multicenter, single-blind, randomized trial

BACKGROUND

Pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) is associated with a non-negligible long-term recurrence rate.

OBJECTIVES

The purpose of this study was to investigate whether PVI combined with 6 short ablation lines on the PVI circumferences (PVI+6L group) yields higher success rates than PVI alone (PVI group).

METHODS

In this multicenter, single-blind, randomized trial, a total of 390 patients with paroxysmal AF were randomly assigned to the PVI group (n = 193) or the PVI+6L group (n = 197). The primary endpoint was freedom from AF/atrial tachycardia recurrence between 91 and 365 days. Secondary endpoints included AF burden, procedural parameters, and complications.

RESULTS

Freedom from atrial tachyarrhythmia was achieved in 160 of 197 patients (81.2%) in the PVI+6L group and 142 of 193 patients (73.6%) in the PVI group (hazard ratio 0.61; 95% confidence interval 0.39-0.97; P = .040). Mean AF burden tended to be lower in the PVI+6L group compared to the PVI group (1.95% vs 0.53%, P = .097). Procedural and ablation times were slightly longer in the PVI+6L group than in the PVI group (130 ± 25 minutes vs 121 ± 28 minutes; P = .002; and 46 ± 14 minutes vs 41 ± 16 minutes, P = .001, respectively). X-ray exposure was similar (60 ± 54 seconds vs 61 ± 60 seconds; P = .964). Complications occurred in 3 patients (1.6%) in the PVI group and 3 patients (1.5%) in the PVI+6L group.

CONCLUSION

In patients with paroxysmal AF undergoing catheter ablation, adding 6 short ablation lines on the PVI circumferences could reduce the AF recurrence rate.

Outcome of High-power Short-duration Radiofrequency Ablation in Combination with Half-Normal Saline Irrigation for the Treatment of Atrial Fibrillation

BACKGROUND

Data regarding the use of high-power short-duration (HPSD) radiofrequency (RF) in combination with half-normal saline irrigation for catheter irrigation is limited.

OBJECTIVES

This study investigated the safety and efficacy of using HPSD RF ablation in combination with half-normal saline irrigation for the treatment of AF.

METHODS

 One hundred consecutive patients with AF underwent RF ablation using HPSD combined with half-normal saline for catheter irrigation. In addition, the following ablation strategies were used: 1 mm tags for the display of ablation lesions on the mapping system, high-frequency jet ventilation (HFJV), low contact force, pacing after ablation to verify areas of noncapture, atrial/ventricular pacing at 500 to 700 ms to aid in catheter stability, use of two skin electrodes to reduce impedance, and post-ablation adenosine infusion. Power was started at 40-45 W and was modulated manually based on impedance changes.

RESULTS

 The average age of patients was 65.2 years and 70% were male. Forty-seven percent had paroxysmal AF and the average CHA₂ DS₂ -VASc score was 2.1±1.6. The average power and lesion duration were 38.1 ± 3.3 W and 8.1 ± 2.3 seconds, respectively. During a median follow-up period of 321 ± 139 days, 89% of the patients remained free from any atrial arrhythmias after a single RF ablation procedure. No procedure-related death, stroke, pericardial effusion, or atrioesophageal fistula occurred during follow-up.

CONCLUSIONS

 Catheter ablation using HPSD RF lesions in combination with half-normal saline irrigation and is safe and effective, and results in high rate of freedom from AF. This article is protected by copyright. All rights reserved.

Sex Differences in Ablation Strategy, Lesion Sets, and Complications of Catheter Ablation for Atrial Fibrillation: An Analysis From the GWTG-AFIB Registry

BACKGROUND

When presenting for atrial fibrillation (AF) ablation, women, compared with men, tend to have more nonpulmonary vein triggers and advanced atrial disease. Whether this informs differences in AF ablation strategy is not well described. We aimed to characterize ablation strategy and complications by sex, using the Get With The Guidelines-AF registry.

METHODS

From the Get With The Guidelines-AF registry ablation feature, we included patients who underwent initial AF ablation procedure between January 7, 2016, and December 27, 2019. Patients were stratified based on AF type (paroxysmal versus nonparoxysmal) and sex. We compared patient demographics, ablation strategy, and complications by sex.

RESULTS

Among 5356 patients from 31 sites who underwent AF ablation, 1969 were women (36.8%). Women, compared with men, were older (66.8±9.6 versus 63.4±10.6, P<0.0001) and were more likely to have paroxysmal AF (59.4% versus 49.5%, P<0.0001). In women with nonparoxysmal AF, left atrial linear ablation was more frequent (roof line: 53.9% versus 45.3%, P=0.0002; inferior mitral isthmus line: 10.2% versus 7.0%, P=0.01; floor line: 46.1% versus 40.6%, P=0.02) than in men. In multivariable analysis, the association between patient sex and complications from ablation was not statistically significant.

CONCLUSIONS

In this US wide AF ablation quality improvement registry, women with nonparoxysmal AF were more likely to receive adjunctive lesion sets compared with men. These findings suggest that patient sex may inform ablation strategy in ways that may not be strongly supported by evidence and emphasize the need to clarify optimal ablation strategies by sex.

Contrast-enhanced computed tomography for optimizing the outcomes of pulmonary vein isolation with cryoablation -the role of isolation of PVs including carina

Purpose

Compared with conventional pulmonary vein isolation (PVI) with radiofrequency ablation, PVI with cryoballoon is an easier and shorter procedure without reconnection, particularly in the superior pulmonary vein. However, the durability of the cryoballoon may be reduced due to anatomical factors and the position of the pulmonary vein (PV). Further, inadequate isolation of the carina leads to recurrence of atrial fibrillation (AF). We aimed to determine whether using contrast-enhanced computed tomography (CT) for patient selection improves the early success rate and prevents the recurrence of AF in PVI with cryoballoon.

Methods

We evaluated patients who underwent ablation for paroxysmal atrial fibrillation in our hospital between July 2019 and November 2020. After excluding patients with contraindications for cryoablation, 50 patients were selected through visual inspection of the results of preoperative contrast-enhanced CT. A treatment plan was established, and the clinical course and outcomes were followed up.

Results

Of the 200 PVs of the 50 patients, only 8 PVs (4%) were incompletely isolated with a single cryoablation. Six of the eight PVs were successfully isolated with additional cryoablation. Only 2 patients (4%) underwent additional PVI with radiofrequency ablation. Four patients had AF recurrence within a mean follow-up period of 14.3 ± 5.1 months. The rate of sinus rhythm maintenance was 92%. PV reconnection was observed in 2 patients. None of the patients had postoperative atrial flutter.

Conclusions

Selecting patients for cryoablation according to contrast-enhanced CT findings made the procedure easier to perform, leading to improved early success rates and clinical course.

Targeting non-pulmonary vein triggers in persistent atrial fibrillation: results from a prospective, multicentre, observational registry

AIMS

We evaluated the efficacy of an ablation strategy empirically targeting pulmonary veins (PVs) and posterior wall (PW) and the prevalence and clinical impact of extrapulmonary trigger inducibility and ablation in a large cohort of patients with persistent atrial fibrillation (PerAF).

METHODS AND RESULTS

A total of 1803 PerAF patients were prospectively enrolled. All patients underwent pulmonary vein antrum isolation (PVAI) extended to the entire PW. A standardized protocol was performed to confirm persistent PVAI and elicit any triggers originating from non-PV sites. All non-PV triggers initiating sustained atrial tachyarrhythmias were ablated. Ablation of non-PV sites triggering non-sustained runs (<30 s) of atrial tachyarrhythmias or promoting frequent premature atrial complexes (≥10/min) was left to operator's discretion. Overall, 1319 (73.2%) patients had documented triggers from non-PV areas. After 17.4 ± 8.5 months of follow-up, the cumulative freedom from atrial tachyarrhythmias among patients without inducible non-PV triggers (n = 484) was 70.2%. Patients with ablation of induced non-PV triggers had a significantly higher arrhythmia control than those whose triggers were not ablated (67.9% vs. 39.4%, respectively; P < 0.001). After adjusting for clinically relevant variables, patients in whom non-PV triggers were documented but not ablated had an increased risk of arrhythmia relapse (hazard ratio: 2.39; 95% confidence interval: 2.01-2.83; P < 0.001).

CONCLUSION

Pulmonary vein antrum isolation extended to the entire PW might provide acceptable long-term arrhythmia-free survival in PerAF patients without inducible non-PV triggers. In our population of PerAF patients, non-PV triggers could be elicited in ∼70% of PerAF patients and their elimination significantly improved outcomes.

Atrial fibrillation ablation in heart failure: What do we know? What can we do?

Atrial fibrillation (AF) and heart failure with reduced ejection fraction (HFrEF) are two conditions that frequently impact reciprocally on each other. Patients with HFrEF have an increased risk of stroke, hospitalization and mortality after they develop AF and vice versa, AF causing deterioration of the ejection fraction is also associated to increased mortality. Catheter ablation has emerged as an effective alternative to antiarrhythmic drug treatment to maintain sinus rhythm and some randomized trials have shown a potential benefit in terms of mortality and hospitalization. This review discusses the available evidence regarding catheter ablation treatment in this specific patient group.

[Pulmonary vein isolation using radiofrequency ablation]

Catheter ablation represents the primary treatment for most arrhythmias. The effectiveness of catheter ablation for the treatment of atrial fibrillation is superior to drug therapy. Therefore, catheter ablation has been established as an increasingly common procedure in clinical routine. In this context, the electrical isolation of the pulmonary veins (PVI) constitutes the cornerstone of the interventional therapy of paroxysmal and persistent atrial fibrillation. This article describes the procedure of pulmonary vein isolation utilizing radiofrequency point-by-point ablation. It shall be a practical guide for the staff in the electrophysiological laboratory. This article continues a series of manuscripts focusing on interventional electrophysiology topics in the course of EP (electrophysiology) training.This article describes the procedure of pulmonary vein isolation utilizing radiofrequency point-by-point ablation. It shall be a practical guide for the staff in the electrophysiological laboratory. This article continues a series of manuscripts dealing with topics of interventional electrophysiology in the course of EP training.

Prevalence and Predictors of Additional Ablation Beyond Pulmonary Vein Isolation in Patients With Paroxysmal Atrial Fibrillation

Background: Pulmonary vein isolation (PVI) is an effective strategy in the treatment of paroxysmal atrial fibrillation (PAF). Yet, there are limited data on additional ablation beyond PVI. In this study, we sought to assess the prevalence, predictors, and outcomes of additional ablation in PAF patients.

Methods: A total of 537 consecutive patients with PAF were retrospectively evaluated for the index procedure. PVI was successfully conducted in all patients, after which electrophysiological study and drug provocation were performed, and additional ablations were delivered for concomitant arrhythmias, non-PV triggers, and low voltage zone (LVZ). The prevalence, predictors, and outcomes of additional ablation were analyzed.

Results: Among 537 consecutive patients, 372 addition ablations were performed in 241 (44.88%) patients, including 252 (67.74%) concomitant arrhythmias in 198 (36.87%) patients, 56 (15.05%) non-PV triggers in 52 (9.68%) patients and 64 (17.20%) LVZ modification in 47 (8.75%) patients. Lower LVEF (OR = 0.937, p = 0.015), AF episode before procedure (OR = 2.990, p = 0.001), AF episode during procedure (OR = 1.998, p = 0.002) and AF episode induced after PVI (OR = 15.958, p < 0.001) were independent predictors of additional ablation. Single-procedure free from atrial arrhythmias at 58.36 ± 7.12 months post-ablation was 70.48%.

Conclusions: Additional ablations were common in patients with PAF for index procedure. Lower LVEF and AF episodes before, during the procedure, and induced after PVI predicts additional ablation.

Pulsed Field Ablation of Paroxysmal Atrial Fibrillation: 1-Year Outcomes of IMPULSE, PEFCAT, and PEFCAT II

OBJECTIVES

This study sought to determine whether durable pulmonary vein isolation (PVI) using pulsed field ablation (PFA) translates to freedom from atrial fibrillation recurrence without an increase in adverse events.

BACKGROUND

PFA is a nonthermal ablative modality that, in preclinical studies, is able to preferentially ablate myocardial tissue with minimal effect on surrounding tissues. Herein, we present 1-year clinical outcomes of PFA.

METHODS

In 3 multicenter studies (IMPULSE [A Safety and Feasibility Study of the IOWA Approach Endocardial Ablation System to Treat Atrial Fibrillation], PEFCAT [A Safety and Feasibility Study of the FARAPULSE Endocardial Ablation System to Treat Paroxysmal Atrial Fibrillation], and PEFCAT II [Expanded Safety and Feasibility Study of the FARAPULSE Endocardial Multi Ablation System to Treat Paroxysmal Atrial Fibrillation]), paroxysmal atrial fibrillation patients underwent PVI using a basket or flower PFA catheter. Invasive remapping was performed at ∼2 to 3 months, and reconnected PVs were reisolated with PFA or radiofrequency ablation. After a 90-day blanking period, arrhythmia recurrence was assessed over 1-year follow-up.

RESULTS

In 121 patients, acute PVI was achieved in 100% of PVs with PFA alone. PV remapping, performed in 110 patients at 93.0 ± 30.1 days, demonstrated durable PVI in 84.8% of PVs (64.5% of patients), and 96.0% of PVs (84.1% of patients) treated with the optimized biphasic energy PFA waveform. Primary adverse events occurred in 2.5% of patients (2 pericardial effusions or tamponade, 1 hematoma); in addition, there was 1 transient ischemic attack. The 1-year Kaplan-Meier estimates for freedom from any atrial arrhythmia for the entire cohort and for the optimized biphasic energy PFA waveform cohort were 78.5 ± 3.8% and 84.5 ± 5.4%, respectively.

CONCLUSIONS

PVI with a "single-shot" PFA catheter results in excellent PVI durability and acceptable safety with a low 1-year rate of atrial arrhythmia recurrence. These data mitigate concern that the nonthermal ablative mechanism of PFA might mask undiscovered compromises to clinical success. (IMPULSE: A Safety and Feasibility Study of the IOWA Approach Endocardial Ablation System to Treat Atrial Fibrillation, NCT03700385; A Safety and Feasibility Study of the FARAPULSE Endocardial Ablation System to Treat Paroxysmal Atrial Fibrillation, NCT03714178; PEFCAT II Expanded Safety and Feasibility Study of the FARAPULSE Endocardial Multi Ablation System to Treat Paroxysmal Atrial Fibrillation [PEFCAT II], NCT04170608).

Impact of diagnosis-to-ablation time on non-pulmonary vein triggers and ablation outcomes in persistent atrial fibrillation

INTRODUCTION

Non-pulmonary vein (PV) triggers are a major cause of atrial tachyarrhythmia (ATA) recurrence after catheter ablation. However, the effect of the diagnosis-to-ablation time (DAT) on non-PV triggers in persistent atrial fibrillation is unknown.

METHODS AND RESULTS

This observational study evaluated 502 consecutive persistent AF patients who underwent initial ablation. We compared 408 patients whose DAT was <3 years with 94 patients whose DAT was ≥3 years. Following PV and posterior wall isolation, 193 non-PV triggers, including 50 AFs, 30 atrial tachycardias (ATs), and 113 repetitive atrial premature beats, were elicited and ablated in 137 (27%) patients. Specifically, 80 non-PV AF/AT triggers were provoked in 64 (13%) patients, being identified more frequently in the DAT ≥ 3 years group than in the DAT < 3 years group (20% vs. 11%, p = .025) especially with a higher prevalence of coronary sinus/inferior left atrial triggers. During a median follow-up of 770 days, the ATA recurrence-free rate was higher in the DAT < 3 years group than the DAT ≥ 3 years group (79% vs. 53% at 2 years, p < .001). In a multivariate analysis, female sex (odds ratio: 2.70, p = .002) and a longer DAT (odds ratio: 1.13/year, p = .008) were predictors of non-PV AF/AT triggers, and a longer DAT (hazard ratio: 1.12/year, p < .001) and non-PV AT/AF triggers (hazard ratio: 1.79, p = .009) were associated with ATA recurrence.

CONCLUSION

Early ablation after the first diagnosis of persistent AF may reduce emerging non-PV AF/AT triggers and ATA recurrence.

Inducibility of atrial fibrillation after catheter ablation predicts recurrences of atrial fibrillation: a meta-analysis

BACKGROUND

Pulmonary vein isolation (PVI) is a component of standard care for patients with symptomatic atrial fibrillation (AF). Procedural inducibility of AF following PVI has been suggested as predictor of AF recurrence but is discussed controversially. This meta-analysis aimed at evaluating the relevance of electrophysiological inducibility of AF following PVI for future AF recurrences.

METHODS

A literature search of MEDLINE and Web of Science was performed until April 2020. Prospective trials of PVI in patients with AF and post-procedural atrial stimulation to test for inducibility of AF as well as adequate follow-up for AF recurrence (defined as AF >10 s to >10 min at follow-up) were included. Odds ratios (ORs) were analyzed using random-effects models.

RESULTS

A total of 11 trials with 1544 patients (follow-up 7-39 months, age 56 ± 6 years, predominantly male 74 ± 6%) were included. Inducibility of AF post-PVI was predictive for AF recurrence during follow-up (OR 2.08; 95% CI 1.25 to 3.46). Prediction for AF recurrence at follow-up was better for patients with paroxysmal AF (OR 4.06; 95% CI 1.39 to 11.91), stimulation in the CS (OR 2.82, 95% CI 1.17 to 6.79). A trend towards higher ORs was seen without the use of isoproterenol (OR 2.43; 95% CI 1.17 to 5.07), as well as few stimulations during induction and a short definition of AF in meta-regression analyses.

CONCLUSIONS

Electrophysiological inducibility of AF following PVI was predictive for future recurrence of AF, in particular in patients with paroxysmal AF, stimulation in only CS and no use of isoproterenol.

Predictors of recurrent atrial fibrillation following catheter ablation

INTRODUCTION

Atrial fibrillation (AF) is a complex and multi-factorial rhythm disorder. Catheter ablation is widely used for the management of AF. However, it is limited by relapse of the arrhythmia necessitating repeat procedures.

AREAS COVERED

This review aims to discuss the predictors of post-ablation recurrent AF including age, gender, genetic predisposition, AF type and duration, comorbidities, lifestyle factors, echocardiographic parameters of heart chambers, left atrial fibrosis and ablation strategies and targets. An extensive literature search was undertaken on PubMed and Google Scholar to obtain full texts of relevant AF-related articles.

EXPERT OPINION

Maintenance of stable sinus rhythm is the main intended outcome of AF ablation. Therefore, it is very crucial to identify the risk factors that may influence the ablation success. Most of these predictors such as comorbidities, ablation strategy and targets and lifestyle factors are either reversible or modifiable. Thus, not only the awareness of these known risk factors by both patients and their physicians but also future research to identify the unknown predictors are critical to optimize care in this multi-faceted morbidity.

Anatomical insights into posterior wall isolation in patients with atrial fibrillation: A hypothesis to protect the esophagus

INTRODUCTION

Left atrial posterior wall (LAPW) isolation may be performed as an additional atrial fibrillation (AF) ablation strategy based on pulmonary vein isolation. A modified posterior-inferior line (MPL) was proposed for reducing esophageal injury. The aim of this study was to evaluate the anatomical characteristics of the MPL, compared with the conventional posterior line (CPL).

METHODS AND RESULTS

Multidetector computed tomography was performed in 102 consecutive AF patients (male/female = 60/42) preoperative, and the parameters were evaluated as follows: the distance from MPL and CPL to the esophagus, fat pad presence and thickness in the course of MPL and CPL, and the esophageal route below CPL. The average distance from the MPL to the esophagus was longer than from CPL to the esophagus (3.7 ± 1.5 vs. 1.7 ± 0.4 mm, p < .001). Proportion of fat pad was higher in the course of MPL than CPL. The myocardium tissue and fat pad under MPL was thicker than under CPL (2.9 ± 1.1 vs. 1.6 ± 0.3 mm, p < .001; 1.4 ± 0.6 vs. 0.9 ± 0.2 mm, p < .001), respectively. In patients whose esophagus was unconfined in a triangular space at the left inferior pulmonary vein level, the average distance from MPL to esophagus was longer than the confined patients (4.0 ± 1.7 vs. 3.2 ± 1.0 mm, p = .001).

CONCLUSION

The MPL was far away from the esophagus with thicker myocardium tissue and more fat pad than the CPL; thus, MPL could serve as a favorable alternative in linear ablation for LAPW isolation.

PRECAF Randomized Controlled Trial

BACKGROUND

We have previously shown that the presence of dual muscular coronary sinus (CS) to left atrial (LA) connections, coupled with rate-dependent unidirectional block in one limb, is associated with atrial fibrillation (AF) induction. This study sought to examine whether ablation of distal CS to LA connections at a first AF ablation reduces arrhythmia recurrence during follow-up.

METHODS

In this single-center, randomized, controlled trial, 35 consecutive patients with drug-refractory AF undergoing first-time ablation between August 2018 and August 2019, were randomly assigned to (1) standard ablation (pulmonary vein isolation and nonpulmonary vein trigger ablation) versus (2) standard ablation plus elimination of distal CS to LA connections targeting the earliest LA activation during distal CS pacing with a deca-polar catheter placed with its proximal electrode at the ostium. Change of the local CS atrial electrogram and LA activation sequence to early activation of the LA septum or roof during distal CS pacing were the end point for CS-LA connection elimination.

RESULTS

Thirty patients completed 6 months study follow-up (15 patients in each group). Demographic characteristics including age and AF persistence were similar in both groups. After a mean follow-up of 170±22 days, there were 7 atrial arrhythmia recurrences in the standard group and 1 recurrence in the CS-LA connection elimination group (46.7% versus 6.7%, hazard ratio, 0.12, P=0.047).

CONCLUSIONS

Elimination of distal CS to LA connections reduced atrial arrhythmia recurrences compared with standard pulmonary vein isolation and nonpulmonary vein trigger ablation in patients undergoing a first AF ablation procedure in a small randomized study. This strategy warrants further evaluation in a multicenter randomized trial. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03646643.

Higher Pulmonary Arterial Pressure Was Related to Non-Pulmonary Vein Atrial Tachyarrhythmia

Recurrence of atrial tachyarrhythmias (ATA) following catheter ablation for atrial fibrillation (AF) is often associated with the recovery of conduction into previously isolated pulmonary veins (PVs). Little evidence concerning repeat PV isolation (PVI) and non-PV ATA ablation has been reported. This study aimed to explore the clinical outcome of recurrent ATA ablation after PVI and the difference between patients with and without non-PV ATA.A total of 49 patients without structural heart diseases who received catheter ablation for recurrent AF between January 2014 and December 2018 were recruited (prior ablation with PVI only 71.4% and PVI with cavotricuspid isthmus line ablation 28.6%). Patients were divided into two groups according to the presence or absence of non-PV ATA.Most patients (53.1%) experienced very late recurrence with a median duration of 15 months. A total of 15 patients had non-PV ATA and received non-PV ATA ablation whereas 34 patients received only repeat PVI for reconnected PVs. A higher pulmonary arterial systolic pressure (PASP) was associated with non-PV ATA (odds ratio: 1.161; 95% confidence interval: 1.021-1.321; P = 0.023). During 4.7 ± 1 months, 4/15 (26.7%) and 1/34 (2.9%) patients with and without non-PV ATA, respectively, had ATA recurrence (P = 0.011). The cumulative incidence of ATA recurrence after repeat ablation was significantly lower in patients without non-PV ATA (P = 0.013).In our study, a high PASP was associated with non-PV ATA in patients with recurrent AF. Repeat PVI had a high rate of maintenance of sinus rhythm in patients without non-PV ATA.

Association between the locations of non-pulmonary vein triggers and ablation outcomes in repeat procedures after cryoballoon ablation of paroxysmal atrial fibrillation

PURPOSE

We examined the characteristics of non-pulmonary vein (PV) triggers in repeat ablation after cryoballoon ablation for paroxysmal atrial fibrillation (PAF).

METHODS

This study evaluated 119 patients undergoing a second ablation procedure for recurrent atrial tachyarrhythmia (ATA) after cryoballoon PV isolation (CB-PVI) for PAF.

RESULTS

Fifty-three of 119 (45%) patients had PV reconnection. All reconnected PVs were isolated. No non-PV triggers were elicited in 42/119 (35%) patients (NNPV group). In 77/119 (65%) patients, 139 isoproterenol-induced non-PV triggers, including 45 triggers that initiated AF, were identified. Non-PV triggers initiating AF were observed at the superior vena cava (SVC), left atrial posterior wall (LAPW) including the PV antra, interatrial septum, right atrium, left atrial appendage/mitral anulus, and coronary sinus in 14 (12%), 10 (8%), 8 (7%), 7 (6%), 4 (3%), and 2 (2%) patients, respectively. Non-PV triggers originated from only the SVC and/or LAPW including the PV antra, and the SVC and/or LAPW was isolated in 18/119 (15%) patients (SVC/LAPW group). Non-PV triggers originating from other sites were focally ablated in 59/119 (50%) patients (OS group). During a median 461 days of follow-up, 39/42 (93%), 17/18 (94%), and 38/59 (64%) patients in the NNPV, SVC/LAPW, and OS groups, respectively, remained ATA recurrence-free. The recurrence rate was higher in the OS group than in the NNPV (P = 0.005) or SVC/LAPW groups (P = 0.042).

CONCLUSIONS

Over half of patients had non-PV triggers at subsequent ablation after CB-PVI. Non-PV triggers from the SVC/LAPW can be eliminated more successfully than triggers from other sites.

The Clinical Application of the Deep Learning Technique for Predicting Trigger Origins in Patients With Paroxysmal Atrial Fibrillation With Catheter Ablation

Background:

Non–pulmonary vein (NPV) trigger has been reported as an important predictor of recurrence post–atrial fibrillation ablation. Elimination of NPV triggers can reduce the recurrence of postablation atrial fibrillation. Deep learning was applied to preablation pulmonary vein computed tomography geometric slices to create a prediction model for NPV triggers in patients with paroxysmal atrial fibrillation.

Methods:

We retrospectively analyzed 521 patients with paroxysmal atrial fibrillation who underwent catheter ablation of paroxysmal atrial fibrillation. Among them, pulmonary vein computed tomography geometric slices from 358 patients with nonrecurrent atrial fibrillation (1–3 mm interspace per slice, 20–200 slices for each patient, ranging from the upper border of the left atrium to the bottom of the heart, for a total of 23 683 images of slices) were used in the deep learning process, the ResNet34 of the neural network, to create the prediction model of the NPV trigger. There were 298 (83.2%) patients with only pulmonary vein triggers and 60 (16.8%) patients with NPV triggers±pulmonary vein triggers. The patients were randomly assigned to either training, validation, or test groups, and their data were allocated according to those sets. The image datasets were split into training (n=17 340), validation (n=3491), and testing (n=2852) groups, which had completely independent sets of patients.

Results:

The accuracy of prediction in each pulmonary vein computed tomography image for NPV trigger was up to 82.4±2.0%. The sensitivity and specificity were 64.3±5.4% and 88.4±1.9%, respectively. For each patient, the accuracy of prediction for a NPV trigger was 88.6±2.3%. The sensitivity and specificity were 75.0±5.8% and 95.7±1.8%, respectively. The area under the curve for each image and patient were 0.82±0.01 and 0.88±0.07, respectively.

Conclusions:

The deep learning model using preablation pulmonary vein computed tomography can be applied to predict the trigger origins in patients with paroxysmal atrial fibrillation receiving catheter ablation. The application of this model may identify patients with a high risk of NPV trigger before ablation.

Efficacy of isoproterenol in the evaluation of dormant conduction and arrhythmogenic foci identification in atrial fibrillation ablation

Background

Catheter ablation for atrial fibrillation (AF) is an established therapy. However, postoperative recurrence is a serious issue caused by the reconduction of the isolated pulmonary veins (PV) and the onset of non-PV foci. The objectives of this study were to elucidate dormant conduction, confirm PV arrhythmia substrate, induce non-PV foci after PV isolation, and assess the acute efficacy of high dose isoproterenol (ISP) when administered in addition to adenosine.

Methods

The study consisted of 100 patients with drug-refractory AF (paroxysmal and persistent) who underwent ablation therapy (either radio-frequency or cryoballoon ablation) as the first-line of therapy at our hospital. All patients first underwent PV isolation (PVI) and were administered adenosine followed by ISP (6 μg × 5 min). The effects were observed, and the therapeutic strategy was evaluated.

Results

Persistent dormant conduction due to ISP administration was observed in 13 patients. In over half of the patients, arrhythmia substrates were identified in the PV. Ten patients presented with persistent PV firing. The ablation of non-PV foci was additionally performed in 23 patients.

Conclusions

We found that dormant conduction, as a result of ISP administration, is persistent and ISP is useful when performing an ablation. In addition, ISP administration is useful for the identification of PV arrhythmia substrates and induction of non-PV foci. However, the effectiveness of ISP may be partially due to the complementary effect of adenosine, and, therefore, a combination of the two drugs seems preferable.

Beyond Pulmonary Vein Isolation in Nonparoxysmal Atrial Fibrillation: Posterior Wall, Vein of Marshall, Coronary Sinus, Superior Vena Cava, and Left Atrial Appendage

The optimal ablation strategy for non-paroxysmal atrial fibrillation remains controversial. Non-PV triggers have been shown to have a major arrhythmogenic role in these patients. Common sources of non-PV triggers are: posterior wall, left atrial appendage, superior vena cava, coronary sinus, vein of Marshall, interatrial septum, crista terminalis/Eustachian ridge, and mitral and tricuspid valve annuli. These sites are targeted empirically in selected cases or if significant ectopy is noted (with or without a drug challenge), to improve outcomes in patients with non-paroxysmal atrial fibrillation. This article focuses on summarizing the current evidence and the approach to mapping and ablation of these frequent non-PV trigger sites.

Stroke Risk in Patients With Atrial Fibrillation Undergoing Electrical Isolation of the Left Atrial Appendage

BACKGROUND

Loss of contractility leading to stasis of blood flow following left atrial appendage electrical isolation (LAAEI) could lead to thrombus formation.

OBJECTIVES

This study evaluated the incidence of thromboembolic events (TE) in post-LAAEI cases "on" and "off" oral anticoagulation (OAC).

METHODS

A total of 1,854 consecutive post-LAAEI patients with follow-up transesophageal echocardiography (TEE) performed in sinus rhythm at 6 months to assess left atrial appendage (LAA) function were included in this analysis.

RESULTS

The TEE at 6 months revealed preserved LAA velocity, contractility, and consistent A waves in 336 (18%) and abnormal parameters in the remaining 1,518 patients. In the post-ablation period, all 336 patients with preserved LAA function were off OAC. At long-term follow-up, patients with normal LAA function did not experience any stroke events. Of the 1,518 patients with abnormal LAA contractility, 1,086 remained on OAC, and the incidence of stroke/transient ischemic attack (TIA) in this population was 18 of 1,086 (1.7%), whereas the number of TE events in the off-OAC patients (n = 432) was 72 (16.7%); p < 0.001. Of the 90 patients with stroke, 84 received left atrial appendage occlusion (LAAO) devices. At median 12.4 months (interquartile range: 9.8 to 15.3 months) of device implantation, 2 (2.4%) patients were on OAC because of high stroke risk or personal preference, whereas 81 patients discontinued OAC after LAAO device implantation without any TE events.

CONCLUSIONS

LAAEI is associated with a significant risk of stroke that can be effectively reduced by optimal uninterrupted OAC or LAAO devices.

Long-term Outcome of Pulmonary Vein Isolation Versus Amiodarone Therapy in Patients with Coexistent Persistent AF and Congestive Heart Failure

Although pharmacological rhythm control of AF in patients with heart failure with reduced ejection fraction (HFrEF) does not seem to provide any benefit over rate control, catheter ablation of AF has been shown to improve clinical outcomes. These results can be explained with higher success rates of catheter ablation in restoring and maintaining sinus rhythm compared with antiarrhythmic drugs. In addition, pharmacotherapy is not void of side-effects, which are thought to offset its potential antiarrhythmic benefits. Therefore, efforts should be made towards optimisation of ablation techniques for AF in patients with HFrEF.

Cardiac MRI and Fibrosis Quantification

Left atrial fibrosis plays an important role in the pathophysiology of atrial fibrillation. Left atrial ablation is an effective and increasingly used strategy to restore and maintain sinus rhythm in patients with atrial fibrillation. Late gadolinium enhancement (LGE) MRI and custom image analysis software have been used to visualize and quantify preablation atrial fibrosis and postablation scar and new fibrosis formation. This article reviews technical aspects of imaging atrial fibrosis/scar by LGE-MRI; use of atrial fibrosis and scar in predicting outcomes; applications of LGE-MRI to assess ablation lesions and optimize ablation parameters while avoiding collateral damage.