Mitral valve prolapse: arrhythmic risk during pregnancy and postpartum

BACKGROUND AND AIMS

Arrhythmic mitral valve prolapse (AMVP) is linked to life-threatening ventricular arrhythmias (VAs), and young women are considered at high risk. Cases of AMVP in women with malignant VA during pregnancy have emerged, but the arrhythmic risk during pregnancy is unknown. The authors aimed to describe features of women with high-risk AMVP who developed malignant VA during the perinatal period and to assess if pregnancy and the postpartum period were associated with a higher risk of malignant VA.

METHODS

This retrospective international multi-centre case series included high-risk women with AMVP who experienced malignant VA and at least one pregnancy. Malignant VA included ventricular fibrillation, sustained ventricular tachycardia, or appropriate shock from an implantable cardioverter defibrillator. The authors compared the incidence of malignant VA in non-pregnant periods and perinatal period; the latter defined as occurring during pregnancy and within 6 months after delivery.

RESULTS

The authors included 18 women with AMVP from 11 centres. During 7.5 (interquartile range 5.8-16.6) years of follow-up, 37 malignant VAs occurred, of which 18 were pregnancy related occurring in 13 (72%) unique patients. Pregnancy and 6 months after delivery showed increased incidence rate of malignant VA compared to the non-pregnancy period (univariate incidence rate ratio 2.66, 95% confidence interval 1.23-5.76).

CONCLUSIONS

The perinatal period could impose increased risk of malignant VA in women with high-risk AMVP. The data may provide general guidance for pre-conception counselling and for nuanced shared decision-making between patients and clinicians.

Case Report: Pulsed field ablation for epicardial right-sided accessory pathway

We present a case of a 32-year-old male with a history of palpitations and preexcitation on ECG who underwent altogether four failed catheter ablations using different approaches in the two other electrophysiology centers within two years. ECG showed overt preexcitation with a positive delta wave in lead I and negative in leads V1-V3, suggesting a right free wall accessory pathway. During the electrophysiological study, the accessory pathway was localized on the free lateral wall. However, the electrograms and mapping during atrial and ventricular pacing suggested the presence of true epicardial accessory pathway. Repeated radiofrequency energy delivery with the support of the steerable sheath and excellent contact (as assessed by intracardiac echocardiography) at the earliest ventricular activation was not successful. Therefore, the Farawave catheter (Boston Scientific, Inc) was used, and a flower configuration with the intention to cover the entire atrial attachment of the pathway during ventricular pacing was selected. Application of pulsed field resulted in interruption of accessory pathway conduction. An electrophysiological study one year later confirmed the persistent effect of ablation. This case illustrates the potential utility of pulsed field energy for the ablation of atrial insertion of the accessory pathway with an epicardial course. Such an approach can avoid epicardial mapping and access and may improve the safety of the procedure.

Efficacy and Safety of Stereotactic Radiotherapy in Patients With Recurrent Ventricular Tachycardias: The Czech Experience

BACKGROUND

Stereotactic arrhythmia radiotherapy (STAR) has been proposed recently in patients with refractory ventricular tachycardia (VT).

OBJECTIVES

The purpose of this study was to describe the efficacy and safety of STAR in the Czech Republic.

METHODS

VT patients were recruited in 2 expert centers after at least 1 previously failed catheter ablation (CA). A precise strategy of target volume determination and CA was used in 17 patients treated from December 2018 until June 2022 (EFFICACY cohort). This group, together with an earlier series of 19 patients with less-defined treatment strategies, composed the SAFETY cohort (n = 36). A dose of 25 Gy was delivered.

RESULTS

In the EFFICACY cohort, the burden of implantable cardioverter-defibrillator therapies decreased, and this drop reached significance for direct current shocks (1.9 ± 3.2 vs 0.1 ± 0.2 per month; P = 0.03). Eight patients (47%) underwent repeated CA for recurrences of VT during 13.7 ± 11.6 months. In the SAFETY cohort (32 procedures, follow-up >6 months), 8 patients (25%) presented with a progression of mitral valve regurgitation, and 3 (9%) required intervention (median follow-up of 33.5 months). Two cases of esophagitis (6%) were seen with 1 death caused by the esophago-pericardial fistula (3%). A total of 18 patients (50%) died during the median follow-up of 26.9 months.

CONCLUSIONS

Although STAR may not be very effective in preventing VT recurrences after failed CA in an expert center, it can still modify the arrhythmogenic substrate, and when used with additional CA, reduce the number of implantable cardioverter-defibrillator shocks. Potentially serious sides effects require close follow-up.

First-in-human clinical series of a novel conformable large-lattice pulsed field ablation catheter for pulmonary vein isolation

AIMS

Pulsed field ablation (PFA) has significant advantages over conventional thermal ablation of atrial fibrillation (AF). This first-in-human, single-arm trial to treat paroxysmal AF (PAF) assessed the efficiency, safety, pulmonary vein isolation (PVI) durability and one-year clinical effectiveness of an 8 Fr, large-lattice, conformable single-shot PFA catheter together with a dedicated electroanatomical mapping system.

METHODS AND RESULTS

After rendering the PV anatomy, the PFA catheter delivered monopolar, biphasic pulse trains (5-6 s per application; ∼4 applications per PV). Three waveforms were tested: PULSE1, PULSE2, and PULSE3. Follow-up included ECGs, Holters at 6 and 12 months, and symptomatic and scheduled transtelephonic monitoring. The primary and secondary efficacy endpoints were acute PVI and post-blanking atrial arrhythmia recurrence, respectively. Invasive remapping was conducted ∼75 days post-ablation. At three centres, PVI was performed by five operators in 85 patients using PULSE1 (n = 30), PULSE2 (n = 20), and PULSE3 (n = 35). Acute PVI was achieved in 100% of PVs using 3.9 ± 1.4 PFA applications per PV. Overall procedure, transpired ablation, PFA catheter dwell and fluoroscopy times were 56.5 ± 21.6, 10.0 ± 6.0, 19.1 ± 9.3, and 5.7 ± 3.9 min, respectively. No pre-defined primary safety events occurred. Upon remapping, PVI durability was 90% and 99% on a per-vein basis for the total and PULSE3 cohort, respectively. The Kaplan-Meier estimate of one-year freedom from atrial arrhythmias was 81.8% (95% CI 70.2-89.2%) for the total, and 100% (95% CI 80.6-100%) for the PULSE3 cohort.

CONCLUSION

Pulmonary vein isolation (PVI) utilizing a conformable single-shot PFA catheter to treat PAF was efficient, safe, and effective, with durable lesions demonstrated upon remapping.

Impact of Left Atrial Posterior Wall Ablation During Pulsed-Field Ablation for Persistent Atrial Fibrillation

BACKGROUND

Pulmonary vein isolation (PVI) alone is insufficient to treat many patients with persistent atrial fibrillation (PersAF). Adjunctive left atrial posterior wall (LAPW) ablation with thermal technologies has revealed lack of efficacy, perhaps limited by the difficulty in achieving lesion durability amid concerns of esophageal injury.

OBJECTIVES

This study aims to compare the safety and effectiveness of PVI + LAPW ablation vs PVI in patients with PersAF using pulsed-field ablation (PFA).

METHODS

In a retrospective analysis of the MANIFEST-PF (Multi-National Survey on the Methods, Efficacy, and Safety on the Post-approval Clinical Use of Pulsed Field Ablation) registry, we studied consecutive PersAF patients undergoing post-approval treatment with a pentaspline PFA catheter. The primary effectiveness outcome was freedom from any atrial arrhythmia of ≥30 seconds. Safety outcomes included the composite of acute and chronic major adverse events.

RESULTS

Of the 547 patients with PersAF who underwent PFA, 131 (24%) received adjunctive LAPW ablation. Compared to PVI-alone, patients receiving adjunctive LAPW ablation were younger (65 vs 67 years of age, P = 0.08), had a lower CHA2DS2-VASc score (2.3 ± 1.6 vs 2.6 ± 1.6, P = 0.08), and were more likely to receive electroanatomical mapping (48.1% vs 39.0%, P = 0.07) and intracardiac echocardiography imaging (46.1% vs 17.1%, P < 0.001). The 1-year Kaplan-Meier estimate for freedom from atrial arrhythmias was not statistically different between groups in the full (PVI + LAPW: 66.4%; 95% CI: 57.6%-74.4% vs PVI: 73.1%; 95% CI: 68.5%-77.2%; P = 0.68) and propensity-matched cohorts (PVI + LAPW: 71.7% vs PVI: 68.5%; P = 0.34). There was also no significant difference in major adverse events between the groups (2.2% vs 1.4%, respectively, P = 0.51).

CONCLUSIONS

In patients with PersAF undergoing PFA, as compared to PVI-alone, adjunctive LAPW ablation did not improve freedom from atrial arrhythmia at 12 months.

Clinical Outcomes by Sex After Pulsed Field Ablation of Atrial Fibrillation

Importance

Previous studies evaluating the association of patient sex with clinical outcomes using conventional thermal ablative modalities for atrial fibrillation (AF) such as radiofrequency or cryoablation are controversial due to mixed results. Pulsed field ablation (PFA) is a novel AF ablation energy modality that has demonstrated preferential myocardial tissue ablation with a unique safety profile.

Objective

To compare sex differences in patients undergoing PFA for AF in the Multinational Survey on the Methods, Efficacy, and Safety on the Postapproval Clinical Use of Pulsed Field Ablation (MANIFEST-PF) registry.

Design, Setting, and Participants

This was a retrospective cohort study of MANIFEST-PF registry data, which included consecutive patients undergoing postregulatory approval treatment with PFA to treat AF between March 2021 and May 2022 with a median follow-up of 1 year. MANIFEST-PF is a multinational, retrospectively analyzed, prospectively enrolled patient-level registry including 24 European centers. The study included all consecutive registry patients (age ≥18 years) who underwent first-ever PFA for paroxysmal or persistent AF.

Exposure

PFA was performed on patients with AF. All patients underwent pulmonary vein isolation and additional ablation, which was performed at the discretion of the operator.

Main Outcomes and Measures

The primary effectiveness outcome was freedom from clinically documented atrial arrhythmia for 30 seconds or longer after a 3-month blanking period. The primary safety outcome was the composite of acute (<7 days postprocedure) and chronic (>7 days) major adverse events (MAEs).

Results

Of 1568 patients (mean [SD] age, 64.5 [11.5] years; 1015 male [64.7%]) with AF who underwent PFA, female patients, as compared with male patients, were older (mean [SD] age, 68 [10] years vs 62 [12] years; P < .001), had more paroxysmal AF (70.2% [388 of 553] vs 62.4% [633 of 1015]; P = .002) but had fewer comorbidities such as coronary disease (9% [38 of 553] vs 15.9% [129 of 1015]; P < .001), heart failure (10.5% [58 of 553] vs 16.6% [168 of 1015]; P = .001), and sleep apnea (4.7% [18 of 553] vs 11.7% [84 of 1015]; P < .001). Pulmonary vein isolation was performed in 99.8% of female (552 of 553) and 98.9% of male (1004 of 1015; P = .90) patients. Additional ablation was performed in 22.4% of female (124 of 553) and 23.1% of male (235 of 1015; P = .79) patients. The 1-year Kaplan-Meier estimate for freedom from atrial arrhythmia was similar in male and female patients (79.0%; 95% CI, 76.3%-81.5% vs 76.3%; 95% CI, 72.5%-79.8%; P = .28). There was also no significant difference in acute major AEs between groups (male, 1.5% [16 of 1015] vs female, 2.5% [14 of 553]; P = .19).

Conclusion and Relevance

Results of this cohort study suggest that after PFA for AF, there were no significant sex differences in clinical effectiveness or safety events.

Acute Effect of Atrial Fibrillation on Circulating Natriuretic Peptides: The Influence of Heart Rate, Rhythm Irregularity, and Left Atrial Pressure Overload

Plasma natriuretic peptides (NPs) are increased in patients with atrial fibrillation (AF) compared with the patients with sinus rhythm. This study investigated whether this phenomenon is intrinsic to heart rhythm irregularity and independent of the heart rate and left atrial pressure (LAP) overload. We investigated 46 patients (age: 59 ± 10 years, male gender: 77%) with non-valvular paroxysmal AF who were scheduled for catheter ablation and had documented stable sinus rhythm for at least 18 hours before the procedure. All patients underwent direct measurement of right atrial pressure and LAP, simultaneously with assessment of plasma B-type NP, N-terminal pro-brain NP, and mid-regional pro-atrial NP. The baseline measurement was followed by induction of AF by rapid atrial pacing in the first 24 patients and by regular pacing from the coronary sinus at 100/min (corresponding to the mean heart rate during induced AF) in the latter 22 patients. Hemodynamic assessment and blood sampling were repeated after 20 min of the ongoing AF or fast regular paging. The baseline characteristics and hemodynamic measurements were comparable between study groups; however, patients in the regular atrial pacing group had a higher body mass index and a larger left atrial diameter compared with the induced AF group. Plasma levels of all 3 NPs increased significantly during induced AF but not during fast regular pacing, and the increase of NPs was independent of right atrial pressure and LAP. Baseline concentrations of NPs and heart rhythm irregularity were the only independent predictors of increased NPs.

Decreased Noise and Identification of Very Low Voltage Signals Using a Novel Electrophysiology Recording System

Aims

The interpretation of intracardiac electrograms recorded from conventional electrophysiology recording systems is frequently impacted by powerline (50/60 Hz) noise and distortion due to notch filtering. This study compares unipolar electrograms recorded simultaneously from a conventional electrophysiology recording system and one of two 3D mapping systems (control system) with those from a novel system (ECGenius, CathVision ApS) designed to reduce noise without the need for conventional filtering.

Methods

Unipolar electrograms were recorded simultaneously from nine consecutive patients undergoing catheter ablation for AF (five patients), atrioventricular nodal re-entrant tachycardia (three patients), or ventricular tachycardia (one patient) over the course of 1 week in 2020.

Results

The noise spectral power of the novel system (49-51 Hz) was 6.1 ± 6.2 times lower than that of the control system. Saturation artefact following pacing (duration 97 ± 85 ms) occurred in eight control recordings and no novel system recordings (p<0.001). High frequency, low amplitude signals and fractionated electrograms apparent on unfiltered novel system unipolar recordings were not present on control recordings. Control system notch filtering obscured His bundle electrograms observable without such filtering using the novel system and induced electrogram distortion that was not present on novel system recordings. Signal saturation occurred in five of seven control system recordings but none of the novel system recordings.

Conclusion

In this study, novel system recordings exhibited less noise and fewer signal artefacts than the conventional control system and did not require notch filtering that distorted electrograms on control recordings. The novel recording system provided superior electrogram data not apparent with conventional systems.

Nonprocedural bleeding after left atrial appendage closure versus direct oral anticoagulants: A subanalysis of the randomized PRAGUE-17 trial

INTRODUCTION

Observational studies have shown low bleeding rates in patients with atrial fibrillation (AF) treated by left atrial appendage closure (LAAC); however, data from randomized studies are lacking. This study compared bleeding events among patients with AF treated by LAAC and nonvitamin K anticoagulants (NOAC).

METHODS

The Prague-17 trial was a prospective, multicenter, randomized trial that compared LAAC to NOAC in high-risk AF patients. The primary endpoint was a composite of a cardioembolic event, cardiovascular death, and major and clinically relevant nonmajor bleeding (CRNMB) defined according to the International Society on Thrombosis and Hemostasis (ISTH).

RESULTS

The trial enrolled 402 patients (201 per arm), and the median follow-up was 3.5 (IQR 2.6-4.2) years. Bleeding occurred in 24 patients (29 events) and 32 patients (40 events) in the LAAC and NOAC groups, respectively. Six of the LAAC bleeding events were procedure/device-related. In the primary intention-to-treat analysis, LAAC was associated with similar rates of ISTH major or CRNMB (sHR 0.75, 95% CI 0.44-1.27, p = 0.28), but with a reduction in nonprocedural major or CRNMB (sHR 0.55, 95% CI 0.31-0.97, p = 0.039). This reduction for nonprocedural bleeding with LAAC was mainly driven by a reduced rate of CRNMB (sHR for major bleeding 0.69, 95% CI 0.34-1.39, p = .30; sHR for CRNMB 0.43, 95% CI 0.18-1.03, p = 0.059). History of bleeding was a predictor of bleeding during follow-up. Gastrointestinal bleeding was the most common bleeding site in both groups.

CONCLUSION

During the 4-year follow-up, LAAC was associated with less nonprocedural bleeding. The reduction is mainly driven by a decrease in CRNMB.

A Focal Ablation Catheter Toggling Between Radiofrequency and Pulsed Field Energy to Treat Atrial Fibrillation

BACKGROUND

Because of its safety, "single-shot" pulsed field ablation (PFA) catheters have been developed for pulmonary vein isolation (PVI). However, most atrial fibrillation (AF) ablation procedures are performed with focal catheters to permit flexibility of lesion sets beyond PVI.

OBJECTIVES

This study sought to determine the safety and efficacy of a focal ablation catheter able to toggle between radiofrequency ablation (RFA) or PFA to treat paroxysmal or persistent AF.

METHODS

In a first-in-human study, a focal 9-mm lattice tip catheter was used for PFA posteriorly and either irrigated RFA (RF/PF) or PFA (PF/PF) anteriorly. Protocol-driven remapping was at ∼3 months postablation. The remapping data prompted PFA waveform evolution: PULSE1 (n = 76), PULSE2 (n = 47), and the optimized PULSE3 (n = 55).

RESULTS

The study included 178 patients (paroxysmal/persistent AF = 70/108). Linear lesions, either PFA or RFA, included 78 mitral, 121 cavotricuspid isthmus, and 130 left atrial roof lines. All lesion sets (100%) were acutely successful. Invasive remapping of 122 patients revealed improvement of PVI durability with waveform evolution: PULSE1: 51%; PULSE2: 87%; and PULSE3: 97%. After 348 ± 652 days of follow-up, the 1-year Kaplan-Meier estimates for freedom from atrial arrhythmias were 78.3% ± 5.0% and 77.9% ± 4.1% for paroxysmal and persistent AF, respectively, and 84.8% ± 4.9% for the subset of persistent AF patients receiving the PULSE3 waveform. There was 1 primary adverse event-inflammatory pericardial effusion not requiring intervention.

CONCLUSIONS

AF ablation with a focal RF/PF catheter allows efficient procedures, chronic lesion durability, and good freedom from atrial arrhythmias-for both paroxysmal and persistent AF. (Safety and Performance Assessment of the Sphere-9 Catheter and the Affera Mapping and RF/PF Ablation System to Treat Atrial Fibrillation; NCT04141007 and NCT04194307).

Safety and Effectiveness of Pulsed Field Ablation to Treat Atrial Fibrillation: One-Year Outcomes From the MANIFEST-PF Registry

BACKGROUND

Pulsed field ablation is a novel nonthermal cardiac ablation modality using ultra-rapid electrical pulses to cause cell death by a mechanism of irreversible electroporation. Unlike the traditional ablation energy sources, pulsed field ablation has demonstrated significant preferentiality to myocardial tissue ablation, and thus avoids certain thermally mediated complications. However, its safety and effectiveness remain unknown in usual clinical care.

METHODS

MANIFEST-PF (Multi-National Survey on the Methods, Efficacy, and Safety on the Post-Approval Clinical Use of Pulsed Field Ablation) is a retrospective, multinational, patient-level registry wherein patients at each center were prospectively included in their respective center registries. The registry included all patients undergoing postapproval treatment with a multielectrode 5-spline pulsed field ablation catheter to treat atrial fibrillation (AF) between March 1, 2021, and May 30, 2022. The primary effectiveness outcome was freedom from clinical documented atrial arrhythmia (AF/atrial flutter/atrial tachycardia) of ≥30 seconds on the basis of electrocardiographic data after a 3-month blanking period (on or off antiarrhythmic drugs). Safety outcomes included the composite of acute (<7 days postprocedure) and latent (>7 days) major adverse events.

RESULTS

At 24 European centers (77 operators) pulsed field ablation was performed in 1568 patients with AF: age 64.5±11.5 years, female 35%, paroxysmal/persistent AF 65%/32%, CHA₂DS₂-VASc 2.2±1.6, median left ventricular ejection fraction 60%, and left atrial diameter 42 mm. Pulmonary vein isolation was achieved in 99.2% of patients. After a median (interquartile range) follow-up of 367 (289-421) days, the 1-year Kaplan-Meier estimate for freedom from atrial arrhythmia was 78.1% (95% CI, 76.0%-80.0%); clinical effectiveness was more common in patients with paroxysmal AF versus persistent AF (81.6% versus 71.5%; P=0.001). Acute major adverse events occurred in 1.9% of patients.

CONCLUSIONS

In this large observational registry of the postapproval clinical use of pulsed field technology to treat AF, catheter ablation using pulsed field energy was clinically effective in 78% of patients with AF.

STereotactic Arrhythmia Radioablation (STAR): the Standardized Treatment and Outcome Platform for Stereotactic Therapy Of Re-entrant tachycardia by a Multidisciplinary consortium (STOPSTORM.eu) and review of current patterns of STAR practice in Europe

The EU Horizon 2020 Framework-funded Standardized Treatment and Outcome Platform for Stereotactic Therapy Of Re-entrant tachycardia by a Multidisciplinary (STOPSTORM) consortium has been established as a large research network for investigating STereotactic Arrhythmia Radioablation (STAR) for ventricular tachycardia (VT). The aim is to provide a pooled treatment database to evaluate patterns of practice and outcomes of STAR and finally to harmonize STAR within Europe. The consortium comprises 31 clinical and research institutions. The project is divided into nine work packages (WPs): (i) observational cohort; (ii) standardization and harmonization of target delineation; (iii) harmonized prospective cohort; (iv) quality assurance (QA); (v) analysis and evaluation; (vi, ix) ethics and regulations; and (vii, viii) project coordination and dissemination. To provide a review of current clinical STAR practice in Europe, a comprehensive questionnaire was performed at project start. The STOPSTORM Institutions' experience in VT catheter ablation (83% ≥ 20 ann.) and stereotactic body radiotherapy (59% > 200 ann.) was adequate, and 84 STAR treatments were performed until project launch, while 8/22 centres already recruited VT patients in national clinical trials. The majority currently base their target definition on mapping during VT (96%) and/or pace mapping (75%), reduced voltage areas (63%), or late ventricular potentials (75%) during sinus rhythm. The majority currently apply a single-fraction dose of 25 Gy while planning techniques and dose prescription methods vary greatly. The current clinical STAR practice in the STOPSTORM consortium highlights potential areas of optimization and harmonization for substrate mapping, target delineation, motion management, dosimetry, and QA, which will be addressed in the various WPs.

Electrocardiographic findings in patients with arrhythmogenic cardiomyopathy and right bundle branch block ventricular tachycardia

AIMS

Little is known about patients with right bundle branch block (RBBB)-ventricular tachycardia (VT) and arrhythmogenic cardiomyopathy (ACM). Our aims were: (i) to describe electrocardiogram (ECG) characteristics of sinus rhythm (SR) and VT; (ii) to correlate SR with RBBB-VT ECGs; and (iii) to compare VT ECGs with electro-anatomic mapping (EAM) data.

METHODS AND RESULTS

From the European Survey on ACM, 70 patients with spontaneous RBBB-VT were included. Putative left ventricular (LV) sites of origin (SOOs) were estimated with a VT-axis-derived methodology and confirmed by EAM data when available.  Overall, 49 (70%) patients met definite Task Force Criteria. Low QRS voltage predominated in lateral leads (n = 37, 55%), but QRS fragmentation was more frequent in inferior leads (n = 15, 23%). T-wave inversion (TWI) was equally frequent in inferior (n = 28, 42%) and lateral (n = 27, 40%) leads. TWI in inferior leads was associated with reduced LV ejection fraction (LVEF; 46 ± 10 vs. 53 ± 8, P = 0.02). Regarding SOOs, the inferior wall harboured 31 (46%) SOOs, followed by the lateral wall (n = 17, 25%), the anterior wall (n = 15, 22%), and the septum (n = 4, 6%). EAM data were available for 16 patients and showed good concordance with the putative SOOs. In all patients with superior-axis RBBB-VT who underwent endo-epicardial VT activation mapping, VT originated from the LV.

CONCLUSIONS

In patients with ACM and RBBB-VT, RBBB-VTs originated mainly from the inferior and lateral LV walls. SR depolarization and repolarization abnormalities were frequent and associated with underlying variants.

Inflammation and fibrosis characterize different stages of myocardial remodeling in patients after stereotactic body radiotherapy of ventricular myocardium for recurrent ventricular tachycardia

We performed a histological and immunohistochemical analysis of myocardia from 3 patients who underwent radiosurgery and died for various reasons 3 months to 9 months after radiotherapy. In Case 1 (death 3 months after radiotherapy) we observed a sharp transition between relatively intact and irradiated regions. In the myolytic foci, only scattered cardiomyocytes were left and the area was infiltrated by immune cells. Using immunohistochemistry we detected numerous inflammatory cells including CD68+/CD11c+ macrophages, CD4+ and CD8+ T-lymphocytes and some scattered CD20+ B-lymphocytes. Mast cells were diminished in contrast to viable myocardium. In Case 2 and Case 3 (death 6 and 9 months after radiotherapy, respectively) we found mostly fibrosis, infiltration by adipose tissue and foci of calcification. Inflammatory infiltrates were less pronounced. Our observations are in accordance with animal experimental studies and confirm a progress from myolysis to fibrosis. In addition, we demonstrate a role of pro-inflammatory macrophages in the earlier stages of myocardial remodeling after stereotactic radioablation for ventricular tachycardia.

The hemodynamic effect of simulated atrial fibrillation on left ventricular function

INTRODUCTION

Atrial fibrillation (AF) is the most common sustained arrhythmia in humans. The onset of the arrhythmia can significantly impair cardiac function. This hemodynamic deterioration has been explained by several mechanisms such as the loss of atrial contraction, shortening of ventricular filling, or heart rhythm irregularity. This study sought to evaluate the relative hemodynamic contribution of each of these components during in vivo simulated human AF.

METHODS

Twelve patients undergoing catheter ablation for paroxysmal AF were paced simultaneously from the proximal coronary sinus and the His bundle region according to prescribed sequences of irregular R-R intervals with the average rate of 90 and 130 bpm, which were extracted from the database of digital ECG recordings of AF from other patients. The simulated AF was compared to regular atrial pacing with spontaneous atrioventricular conduction and regular simultaneous atrioventricular pacing at the same heart rate. Beat-by-beat left atrial and left ventricular pressures, including LV dP/dT and Tau index were assessed by direct invasive measurement; beat-by-beat stroke volume and cardiac output (index) were assessed by simultaneous pulse-wave doppler intracardiac echocardiography.

RESULTS

Simulated AF led to significant impairment of left ventricular systolic and diastolic function. Both loss of atrial contraction and heart rate irregularity significantly contributed to hemodynamic impairment. This effect was pronounced with increasing heart rate.

CONCLUSION

Our findings strengthen the rationale for therapeutic strategies aiming at rhythm control and heart rate regularization in patients with AF.

Cardioneuroablation focused on the atrioventricular node: a comparison of right and left atrial approach

Background

Radiofrequency catheter ablation of posteromedial left ganglionated plexus is a critical step to eliminate the vagal input to the atrioventricular node (AVN) for the treatment of symptomatic episodes of functional AV block. This ganglionated plexus can be effectively targeted from the coronary sinus (CS) or from the endocardial aspect of the right (RA) and left (LA) atria.

Purpose

We investigated the effect of ablation at individual sites on the suppression of parasympathetic modulation of AVN.

Methods

The study included 20 patients (age: 42±13 years, 45% males) who underwent cardioneuroablation in general anesthesia. Posteromedial left ganglionated plexus was ablated from [1] the CS (proximal 2-cm segment), [2] the RA aspect (between the fossa ovalis and inferior vena cava), and [3] the LA aspect (middle bottom part adjacent to inferior rim of fossa ovalis). Patients were randomly (1:1) assigned to CS-to-RA or RA-to-CS ablation order. LA ablation was always the last step. The response to extracardiac vagus nerve stimulation (ECVS; 50 Hz, 0.05 ms, 1 V/kg [&lt;70V], 5 s) while atrial pacing (100 bpm) was recorded at baseline and after each ablation step. The number of non-AV-conducted beats during the ECVS was considered a measure of AV nodal denervation. Both right and left vagus nerves were sequentially stimulated and the stronger response of the AV node was taken into account.

Results

Temporal development of outcome measure with the progression of ablation is shown in Figure 1. CS ablation resulted in much stronger AV nodal denervation compared to RA ablation (P=0.02). However, RA ablation still provided some effect on top of CS ablation. The combination of CS + RA ablation resulted in complete AVN denervation in 8 (40%) patients. Subsequent LA ablation increased the number of denervated patients to 14 (70%). Two more patients were subsequently denervated by ablation elsewhere. In four patients, AVN denervation was not achieved but their responsiveness to ECVS was significantly suppressed compared to the baseline.

Conclusions

All ablation clusters targeting posteromedial ganglionated plexus convey complementary effects. Biatrial cardioneuroablation seems essential for efficacious suppression of parasympathetic modulation of AVN.

Funding Acknowledgement

Type of funding sources: None.

Importance of bilateral vagus nerve stimulation for effective atrioventricular node denervation during cardioneuroablation

Background

The progression of parasympathetic denervation of the atrioventricular node (AVN) during cardioneuroablation (CNA) can be evaluated by extracardiac vagal stimulation (ECVS). The right vagus nerve is usually used for stimulation (R-ECVS) because the right jugular vein is easily accessible. However, the AVN node is predominantly under the control of the left vagus nerve.

Purpose

To highlight the importance of left vagus stimulation (L-ECVS) for effective AVN denervation.

Methods

Both R-ECVS and L-ECVS (frequency: 50 Hz; pulse width: 0.05 ms; output 1 V / 1 kg; max. 70 V, duration 5 s) was attempted in 80 patients (age: 41±12 years, 45% men) undergoing CNA with stepwise strategy consisting of ablation of right anterior ganglionated plexus (RAGP) followed by ablation of posteromedial left ganglionated plexus (PMLGP). The study objective was the AVN response to L-ECVS (evaluated as the max. R-R interval during stimulation train) at the point when AVN non-reactivity to R-ECVS was achieved.

Results

A total of 59 patients were suitable for the analysis. Of the remaining 21 patients, left (n=14) or right (n=2) jugular veins were not accessible, AVN non-reactivity to L-ECVS was achieved before non-reactivity to R-ECVS (n=4), or AVN denervation was not achieved at all (n=1). At baseline, the AVN response was identical for R-ECVS (max. R-R median: 6.9 s, interquartile range [IQR]: 5.7–8.2 s) and L-ECVS (median: 7.1 s, IQR: 6.0–8.3 s), P=0.44. AVN non-reactivity to R-ECVS was present already at baseline (n=2); was achieved after ablation of RAGP (n=14), after ablation PMLGP (n=38), or after extensive ablation (n=5). At the point of AVN non-reactivity to R-ECVS, the response of AVN to L-ECVS was as follows: none (n=25), 2: 1 AV block (n=13) or complete AV block (n=21). The corresponding median of max. R-R interval was: 1.2 s, IQR: 0.6–4.8 s distributed as shown in Figure 1.

Conclusions

In 34/59 (58%) patients, significant AVN response to L-ECVS persists after reaching AVN non-reactivity to R-ECVS. Stimulation of both vagal nerves tightens the procedural endpoint and may increase the clinical efficacy of CNA, especially in patients with dominant AVN disorder.

Funding Acknowledgement

Type of funding sources: None.

Bipolar ablation of refractory ventricular arrhythmias using a novel dedicated adapter. A multicenter study

Background

Bipolar ablation (BA) recently emerged as an alternative for treatment of ventricular tachycardia (VT) and premature ventricular contractions (PVC) refractory to a classic unipolar ablation (UA). Data on the use of available BA systems is lacking.

Purpose

To determine feasibility, safety and efficacy of a novel BA adapter in consecutive patients with refractory VT/PVC undergoing repeat ablations.

Methods

The study group consisted of consecutive patients with VT/PVC after failure of at least one standard UA who underwent redo procedures performed with a support of BA at six European centers. A second ablation catheter was connected in the position of a return electrode using a novel BA adapter.

Results

Between March 2021 and March 2022 a total number of 19 patients after failed ablation attempts underwent redo procedure using a novel BA adapter (17 males, age 61±11, number of prior ablation attempts 2,5±1,6; range 1–7). The main indication for redo ablation was recurrence of frequent PVC (n=10), VT (n=8) or electrical storm (n=1). Fifteen patients underwent combined UA+BA procedure during redo ablation, whereas 4 remaining patients underwent BA only. Two patients required epicardial access. Mean procedural time was 157±77 minutes. The mean BA time was 367±245s (power 32±9W) and mean UA time was 349±290s (power 43±6W). Apart from 1 anticipated AV block there were no major complications. Minor complications included char formation at 8mm tip electrode and steam pop without sequalae in one VT patient. BA+UA led to acute elimination of clinical PVC/VT in 18 patients. In the remaining 1 patient no effect on clinical VT during UA+BA was observed. The follow up lasted 4±3 months. Six (75%) VT patients remained arrhythmia-free and significant PVC burden reduction was achieved in nine (90%) PVC patients during follow-up. One patient treated for electrical storm experienced a single VT episode after 11 months. One patient after initially failed UA+BA underwent successful bipolar reablation after 2 months.

Conclusions

Bipolar ablation of refractory ventricular arrhythmias using a novel dedicated adapter is feasible, seems safe and effective. These encouraging preliminary results need to be confirmed in properly designed prospective trials.

Funding Acknowledgement

Type of funding sources: None.

Acute and Long-Term Scar Characterization of Venous Ethanol Ablation in the Left Ventricular Summit

BACKGROUND

Venous ethanol ablation (VEA) can be effective for ventricular arrhythmias from the left ventricular summit (LVS); however, there are concerns about excessive ablation by VEA.

OBJECTIVES

The purpose of this study was to delineate and quantify the location, extent, and evolution of ablated tissue after VEA as an intramural ablation technique in the LVS.

METHODS

VEA was performed in 59 patients with LVS ventricular arrhythmias. Targeted intramural veins were selected by electrograms from a 2F octapolar catheter or by guide-wire unipolar signals. Median ethanol delivered was 4 mL (IQR: 4-7 mL). Ablated areas were estimated intraprocedurally as increased echogenicity on intracardiac echocardiography (ICE) and incorporated into 3-dimensional maps. In 44 patients, late gadolinium enhancement cardiac magnetic resonance (CMR) imaged VEA scar and its evolution.

RESULTS

ICE-demonstrated increased intramural echogenicity (median volume of 2 mL; IQR: 1.7-4.3) at the targeted region of the 3-dimensional maps. Post-ethanol CMR showed intramural scar of 2.5 mL (IQR: 2.1-3.5 mL). Early (within 48 hours after VEA) CMR showed microvascular obstruction (MVO) in 30 of 31 patients. Follow-up CMR after a median of 51 (IQR: 41-170) days showed evolution of MVO to scar. ICE echogenicity and CMR scar volumes correlated with each other and with ethanol volume. Ventricular function and interventricular septum remained intact.

CONCLUSIONS

VEA leads to intramural ablation that can be tracked intraprocedurally by ICE and creates regions of MVO that are chronically replaced by myocardial scar. VEA scar volume does not compromise septal integrity or ventricular function.

Autonomic Changes Are More Durable After Radiofrequency Than Pulsed Electric Field Pulmonary Vein Ablation

BACKGROUND

Pulmonary vein isolation (PVI) by radiofrequency (RF) energy is associated with a collateral ganglionated plexi ablation. Pulsed electric field (PEF) is a nonthermal energy source that preferentially affects the myocardial cells and spares neural tissue.

OBJECTIVES

This study investigated whether PVI by a PEF compared with RF energy will result in less prominent alteration of the cardiac autonomic nervous system.

METHODS

A total of 31 patients with atrial fibrillation underwent PVI using a novel lattice-tip catheter and PEF energy (n = 18) or a conventional irrigated-tip catheter and RF energy (n = 13). The response of the sinoatrial node and atrioventricular node to extracardiac high-frequency, high-output, right vagal nerve stimulation was evaluated at baseline and during and at the end of the ablation procedure. Substantial reduction in responsiveness was arbitrarily defined as stimulation-inducible pause <1.5 seconds.

RESULTS

Reduced response of the sinoatrial node was documented in 13 of 13 (100%) and 6 of 18 (33%) patients (P = 0.0001) in RF and PEF groups, respectively. Reduced response of the atrioventricular node was found in 10 of 11 (93%) and 6 of 18 (33%) patients (P = 0.002) in RF and PEF groups, respectively. The major effects were observed predominantly during ablation around the right pulmonary veins. Early recovery of ganglionated plexi function was noticed only in the PEF ablation group. RF ablation resulted in higher acceleration of the sinus rhythm compared with PEF ablation (20 ± 13 beats/min vs 12 ± 10 beats/min; P = 0.04).

CONCLUSIONS

PEF compared with RF energy used for PVI induces significantly weaker and less durable suppression of cardiac autonomic regulations.

POS0512 ANTI-CITRULLINATED PROTEIN ANTIBODY SEROSTATUS DETERMINES 2-YEAR RETENTION OF IV AND SC ABATACEPT IN PATIENTS WITH RA IN A REAL-WORLD SETTING

Background

A treat-to-target approach for RA management is recommended.1,2 However, up to half of patients discontinue DMARD treatment within 18 months.2 Predictive biomarkers, such as anti-citrullinated protein antibodies (ACPAs) and RF, may be useful to stratify patients to the most appropriate treatment. ACTION (AbataCepT In rOutiNe clinical practice; NCT02109666) and ASCORE (Abatacept SubCutaneOus in Routine Clinical PracticE; NCT02090556) were 2-year, international, observational, prospective, multicenter studies of IV and SC abatacept, respectively, for the treatment of RA in routine clinical practice.3,4 Higher retention has been previously reported in patients with double ACPA/RF seropositive RA compared with double ACPA/RF seronegative RA.3,4

Objectives

To assess the independent effect of ACPA or RF single seropositivity on abatacept retention in patients with RA receiving abatacept in a post hoc analysis of ACTION and ASCORE.

Methods

This post hoc analysis included patients aged ≥ 18 years, with active moderate-to-severe RA (ACR/EULAR 2010 criteria) who initiated IV (body weight–adjusted dosing) or SC (125 mg once weekly) abatacept.3,4 Patients were stratified by baseline ACPA/RF status: ACPA+/RF− (ACPA+ only), ACPA/RF double positive (+/+), ACPA−/RF+ (RF+ only), and ACPA/RF double negative (−/−). Abatacept retention rate at 2 years was estimated by Kaplan–Meier (KM) analysis.

Results

Patients with ACPA/RF serostatus data from the ACTION and ASCORE studies (N = 1679 and N = 1748, respectively) were evaluated. Baseline demographic and disease characteristics were similar across studies and serostatus groups (Table 1). In patients with ACPA+ only RA, abatacept retention rates were similar to the +/+ group and greater than the RF+ only and −/− groups (Figure 1). In ASCORE (Figure 1A), retention rates were significantly higher in ACPA+ only and +/+ groups when compared with the −/− group. In contrast, retention rates for patients with RF+ only RA were not significantly different vs −/− patients. Results were similar in ACTION, although the higher retention in the ACPA+ group did not reach statistical significance (Figure 1B).

Table 1.

Baseline demographics and disease characteristics by ACPA/RF status for the ASCORE and ACTION studies

ASCORE+/+RF+ onlyACPA+ only−/−(n = 1079)(n = 142)(n = 184)(n = 343)Age, years57.1 (12.8)58.2 (11.8)57.4 (13.5)57.8 (13.9)DAS28 (CRP)4.7 (1.2)4.6 (1.1)4.4 (1.0)4.8 (1.2)CDAI26.6 (12.5)25.8 (12.0)23.6 (10.9)28.2 (13.2)SDAI28.1 (13.0)27.2 (12.4)24.4 (10.8)29.7 (13.9)ACTION+/+RF+ onlyACPA+ only−/−(n = 1028)(n = 161)(n = 98)(n = 392)Age, years58.2 (12.0)58.4 (13.4)58.5 (14.0)57.0 (13.3)DAS28 (CRP)4.9 (1.1)5.0 (1.1)4.9 (1.0)5.0 (1.1)CDAI28.7 (12.2)29.2 (12.4)28.7 (11.5)30.1 (12.9)SDAI30.4 (13.1)31.2 (13.4)29.8 (11.5)31.7 (13.4)

Data are mean (SD). Patients with missing data for baseline ACPA/RF status are excluded.

Conclusion

In this post hoc analysis of the real-world ACTION and ASCORE studies, ACPA positivity was associated with an increased likelihood of retention over 2 years. Patients with ACPA+ only RA were equally as likely to be retained on abatacept as patients with ACPA/RF double positivity. In contrast, patients with RF+ only RA were less likely to be retained on abatacept over 2 years. These findings suggest that ACPA positivity played a more important role than RF positivity in abatacept retention. The higher retention seen in patients with ACPA+ only vs RF+ only disease demonstrates the key role of ACPA in RA and supports the importance of precision medicine in treating patients.

References

[1]Fraenkel L, et al. Arthritis Care Res (Hoboken) 2021;73:924–39.

[2]Smolen JS, et al. Ann Rheum Dis 2020;79:685–99.

[3]Alten R, et al. Clin Rheumatol 2019;38:1413–24.

[4]Alten R, et al. Ann Rheum Dis 2021;80(suppl 1):OP0180.

Acknowledgements

This study was sponsored by Bristol Myers Squibb. Medical writing and editorial assistance was provided by Fiona Boswell, PhD, of Caudex, and was funded by Bristol Myers Squibb. Study management provided by Syneos (CRO).

Disclosure of Interests

Rieke Alten Speakers bureau: AbbVie, Bristol Myers Squibb, Celltrion, Galapagos, Gilead, Janssen, Lilly, Novartis, Pfizer, Roche, Paid instructor for: AbbVie, Bristol Myers Squibb, Celltrion, Galapagos, Gilead, Janssen, Lilly, Novartis, Pfizer, Roche, Consultant of: AbbVie, Bristol Myers Squibb, Celltrion, Galapagos, Gilead, Janssen, Lilly, Novartis, Pfizer, Roche, Grant/research support from: AbbVie, Bristol Myers Squibb, Celltrion, Galapagos, Gilead, Janssen, Lilly, Novartis, Pfizer, Roche, Christiane Rauch Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Melanie Chartier Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, M.T. Nurmohamed Speakers bureau: AbbVie, Bristol Myers Squibb, Eli Lilly, Janssen, Pfizer, Consultant of: AbbVie, Bristol Myers Squibb, Eli Lilly, Janssen, Pfizer, Grant/research support from: AbbVie, Amgen, Bristol Myers Squibb, Eli Lilly, Galapagos, Janssen, MSD, Pfizer, Sean Connolly Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Maya H Buch Speakers bureau: AbbVie, Consultant of: AbbVie, Galapagos, Gilead, Pfizer, Grant/research support from: Gilead, Pfizer, UCB, Peter Peichl Speakers bureau: GlaxoSmithKline, Janssen, Xavier Mariette Consultant of: Bristol Myers Squibb, Galapagos, GlaxoSmithKline, Janssen, Novartis, Pfizer, Sanofi, UCB, Yusuf Patel: None declared, Sara Marsal Speakers bureau: Bristol Myers Squibb, Lilly, MSD, Novartis - Sandoz, Pfizer, Roche, Consultant of: AbbVie, Galapagos, Pfizer, Sanofi; IMIDomics (executive role), Grant/research support from: AbbVie, Bristol Myers Squibb, Galapagos, Janssen, Lilly, MSD, Novartis - Sandoz, Pfizer, Roche, Sanofi, UCB, Roberto Caporali Speakers bureau: AbbVie, Amgen, Bristol Myers Squibb, Celltrion, Fresenius-Kabi, Galapagos, Janssen, Lilly, MSD, Novartis, Pfizer, Roche, Sandoz, UCB, Consultant of: AbbVie, Amgen, Bristol Myers Squibb, Celltrion, Galapagos, Janssen, Lilly, MSD, Novartis, Pfizer, Sandoz, UCB, Hedley Griffiths Consultant of: Amgen, Raimón Sanmartí Speakers bureau: AbbVie, Bristol Myers Squibb, Lilly, MSD, Pfizer, Roche, Sanofi, Grant/research support from: AbbVie, Bristol Myers Squibb, MSD, Pfizer, Roche, Bettina Bannert Speakers bureau: Novartis Pharma Schweiz AG, Yedid Elbez Consultant of: Bristol Myers Squibb, Employee of: Signifience, Karissa Lozenski Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb.

POS0107 ACPA POSITIVITY DETERMINES REMISSION IN PATIENTS WITH RA TREATED WITH IV AND SC ABATACEPT: A POST HOC ANALYSIS OF THE REAL-WORLD OBSERVATIONAL ACTION AND ASCORE STUDIES

Background

The goal of treatment for RA is achieving low disease activity and/or remission1,2; however, disease course and management can be complicated by additional factors that may be influenced by serostatus. Anti-citrullinated protein antibodies (ACPAs) and RF contribute to a more severe RA disease pattern3 and may be useful in predicting response to treatment.4 ACTION (AbataCepT In rOutiNe clinical practice; NCT02109666) and ASCORE (Abatacept SubCutaneOus in Routine Clinical PracticE; NCT02090556) were 2-year, international, observational, prospective, multicenter studies of IV and SC abatacept, respectively, for the treatment of RA in routine clinical practice.4,5 Previous analyses have shown that ACPA/RF double-positive serostatus was associated with better treatment outcomes compared with ACPA/RF double-negative serostatus.4–6

Objectives

To assess the independent effect of ACPA or RF single seropositivity among patients with RA on achieving remission after treatment with abatacept for 2 years, and to compare outcomes among patients with single versus double serostatus.

Methods

This post hoc analysis included patients from ACTION and ASCORE who initiated IV (body weight–adjusted dosing) or SC abatacept (125 mg once weekly), respectively. Patients were stratified by baseline ACPA/RF status: ACPA+/RF− (ACPA+ only), ACPA/RF double positive (+/+), ACPA−/RF+ (RF+ only), and ACPA/RF double negative (−/−). DAS28 (CRP) and CDAI remission rates (defined as < 2.6 and 0–2.8, respectively) at 2 years for patients who were ACPA+ or RF+ only at baseline were assessed and compared with those who were +/+ and −/−. Patients with missing baseline ACPA/RF status were excluded. Last observation carried forward efficacy analyses were used to impute missing values.

Results

This analysis included 1679 patients from ACTION (ACPA+ only, n = 98; +/+, n = 1028; RF+ only, n = 161; and −/−, n = 392) and 1748 patients from ASCORE (ACPA+ only, n = 184; +/+, n = 1079; RF+ only, n = 142; and −/−, n = 343). Across studies and serogroups, baseline demographics and disease characteristics were similar (data not shown). In both ACTION and ASCORE, a higher proportion of patients who were only ACPA+ achieved DAS28 (CRP) and CDAI remission at 2 years compared with patients who were only RF+ (Figure 1). Additionally, a similar proportion of patients who were only ACPA+ achieved DAS28 (CRP) and CDAI remission at 2 years compared with patients who were +/+. In contrast, a lower proportion of patients who were only RF+ achieved DAS28 (CRP) and CDAI remission at 2 years compared with patients who were +/+.

Conclusion

In this post hoc analysis of real-world data from ACTION and ASCORE, ACPA positivity was associated with an increased likelihood of achieving DAS28 (CRP) and CDAI remission at 2 years. Patients who were ACPA+ only were as likely to achieve remission as +/+ patients, suggesting that RF serostatus had less influence than ACPA serostatus on remission status at 2 years. In line with this, patients who were RF+ only were less likely to achieve remission at 2 years. This is the first large, real-world study to show that ACPA positivity plays a more important role than RF positivity in achieving remission whilst on abatacept. These results highlight the importance of assessing baseline ACPA status when considering treatment options for patients with RA.

References

[1]Smolen JS, et al. Ann Rheum Dis 2020;79:685–99.

[2]Fraenkel L, et al. Arthritis Care Res (Hoboken) 2021;73:924–39.

[3]Katchamart, W, et al. Rheumatol Int 2015;35:1693–9.

[4]Alten R, et al. Ann Rheum Dis 2021;80(suppl 1):OP0180.

[5]Alten R, et al. Clin Rheumatol 2019;38:1413–24.

[6]Alten R, et al. RMD Open 2017;3:e000345.

Acknowledgements

This study was sponsored by Bristol Myers Squibb. Medical writing and editorial assistance was provided by Rachel Rankin, PhD, of Caudex, and was funded by Bristol Myers Squibb. Study management provided by Syneos (CRO).

Disclosure of Interests

Rieke Alten Speakers bureau: AbbVie, Bristol Myers Squibb, Celltrion, Galapagos, Gilead, Janssen, Lilly, Novartis, Pfizer, Roche, Paid instructor for: AbbVie, Bristol Myers Squibb, Celltrion, Galapagos, Gilead, Janssen, Lilly, Novartis, Pfizer, Roche, Consultant of: AbbVie, Bristol Myers Squibb, Celltrion, Galapagos, Gilead, Janssen, Lilly, Novartis, Pfizer, Roche, Grant/research support from: AbbVie, Bristol Myers Squibb, Celltrion, Galapagos, Gilead, Janssen, Lilly, Novartis, Pfizer, Roche, Christiane Rauch Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Melanie Chartier Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, M.T. Nurmohamed Speakers bureau: AbbVie, Bristol Myers Squibb, Eli Lilly, Janssen, Pfizer, Consultant of: AbbVie, Bristol Myers Squibb, Eli Lilly, Janssen, Pfizer, Grant/research support from: AbbVie, Amgen, Bristol Myers Squibb, Eli Lilly, Galapagos, Janssen, MSD, Pfizer, Sean Connolly Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Maya H Buch Speakers bureau: AbbVie, Consultant of: AbbVie, Galapagos, Gilead, Pfizer, Grant/research support from: Gilead, Pfizer, UCB, Peter Peichl Speakers bureau: Janssen, GlaxoSmithKline, Xavier Mariette Consultant of: Bristol Myers Squibb, Galapagos, GlaxoSmithKline, Janssen, Novartis, Pfizer, Sanofi, UCB, Yusuf Patel: None declared, Sara Marsal Speakers bureau: Bristol Myers Squibb, Lilly, MSD, Novartis - Sandoz, Pfizer, Roche, Consultant of: AbbVie, Galapagos, Pfizer, Sanofi; IMIDomics (executive role), Grant/research support from: AbbVie, Bristol Myers Squibb, Galapagos, Janssen, Lilly, MSD, Novartis - Sandoz, Pfizer, Roche, Sanofi, UCB, Roberto Caporali Speakers bureau: AbbVie, Amgen, Bristol Myers Squibb, Celltrion, Fresenius-Kabi, Galapagos, Janssen, Lilly, MSD, Novartis, Pfizer, Roche, Sandoz, UCB, Consultant of: AbbVie, Amgen, Bristol Myers Squibb, Celltrion, Galapagos, Janssen, Lilly, MSD, Novartis, Pfizer, Sandoz, UCB, Hedley Griffiths Consultant of: Amgen, Raimón Sanmartí Speakers bureau: AbbVie, Bristol Myers Squibb, Lilly, MSD, Pfizer, Roche, Sanofi, Grant/research support from: AbbVie, Bristol Myers Squibb, MSD, Pfizer, Roche, Bettina Bannert: None declared, Yedid Elbez Consultant of: Bristol Myers Squibb, Employee of: Signifience, Karissa Lozenski Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb

Multi-national survey on the methods, efficacy, and safety on the post-approval clinical use of pulsed field ablation (MANIFEST-PF)

AIMS

Pulsed field ablation (PFA) is a novel atrial fibrillation (AF) ablation modality that has demonstrated preferential tissue ablation, including no oesophageal damage, in first-in-human clinical trials. In the MANIFEST-PF survey, we investigated the 'real world' performance of the only approved PFA catheter, including acute effectiveness and safety-in particular, rare oesophageal effects and other unforeseen PFA-related complications.

METHODS AND RESULTS

This retrospective survey included all 24 clinical centres using the pentaspline PFA catheter after regulatory approval. Institution-level data were obtained on patient characteristics, procedure parameters, acute efficacy, and adverse events. With an average of 73 patients treated per centre (range 7-291), full cohort included 1758 patients: mean age 61.6 years (range 19-92), female 34%, first-time ablation 94%, paroxysmal/persistent AF 58/35%. Most procedures employed deep sedation without intubation (82.1%), and 15.1% were discharged same day. Pulmonary vein isolation (PVI) was successful in 99.9% (range 98.9-100%). Procedure time was 65 min (38-215). There were no oesophageal complications or phrenic nerve injuries persisting past hospital discharge. Major complications (1.6%) were pericardial tamponade (0.97%) and stroke (0.4%); one stroke resulted in death (0.06%). Minor complications (3.9%) were primarily vascular (3.3%), but also included transient phrenic nerve paresis (0.46%), and TIA (0.11%). Rare complications included coronary artery spasm, haemoptysis, and dry cough persistent for 6 weeks (0.06% each).

CONCLUSION

In a large cohort of unselected patients, PFA was efficacious for PVI, and expressed a safety profile consistent with preferential tissue ablation. However, the frequency of 'generic' catheter complications (tamponade, stroke) underscores the need for improvement.

Cardioneuroablation in patients with a prior pacemaker implant

Funding Acknowledgements

Type of funding sources: None.

Background

Cardioneuroablation (CNA) is an alternative therapeutic method for patients with functional bradyarrhythmias, who are otherwise candidates for permanent pacing. In a specific clinical scenario, CNA can also be a treatment option for patients with already implanted pacemakers.

Purpose

We investigated whether CNA could substitute permanent pacing in selected patients in whom pacemaker is associated with complications, technical failures, or decreased quality of life.

Methods

Among 160 patients who underwent CNA by radiofrequency energy between 2014 and 2022, there were 13 patients (8%) with a pacemaker in whom CNA was indicated as a "substitute" treatment. The reasons were as follows: lead failure (n = 6), recurrent decubitus of the device pocket (n = 1), infective endocarditis (n = 1), recurrent syncope even after pacemaker implantation (n = 1) and discomfort associated with the implanted device (n = 4). In 4 patients, the pacemaker was explanted shortly before CNA because of serious complications. Biatrial CNA was guided anatomically with the use of a 3D mapping system and intracardiac echocardiography. Empirical sites of ganglionated plexi were targeted. The procedural endpoint was unresponsiveness of sinus and AV nodes to extracardiac vagal nerve stimulation.

Results

Patients (n = 13, 77% male, age: 41 ± 12 years) had a pacemaker implanted 11 ± 7 years ago. They responded to atropine (2 mg IV) administration by accelerating the sinus rhythm by 55 ± 33%. CNA was technically successful and uncomplicated in all of them. During the follow-up of 29 ± 16 months (range 6 - 56 months), 2 patients (15%) had a recurrence of syncope. In both, the syncope was reproduced by tilt testing and classified as a pure vasodepressor event. In the remaining patients, the follow-up was uneventful. Elective explantation of the pacing system has so far been performed in 3 of 9 patients, while this is planned in others after reaching a sufficient length of post-procedural follow-up.

Conclusions

CNA is an effective and safe method, which is not only an alternative to the pacemaker implant but can also be used in patients with functional bradyarrhythmias, and previously implanted pacemakers who experience significant adverse events associated with the pacing system.

Heart rate acceleration during cardioneuroablation is a weak predictor of significantly reduced parasympathetic modulation of sinus node

Funding Acknowledgements

Type of funding sources: None.

Introduction

Ablation of superior parasympathetic ganglia is associated with acceleration of sinus rhythm (SR). This has been considered a favorable sign during cardioneuroablation (CNA) for the treatment of functional bradyarrhythmias.

Aim

We studied whether the relative increase in SR frequency (DeltaSR) during CNA is a reliable predictor of significantly reduced parasympathetic modulation of the sinus node (SAN).

Methods

In patients undergoing CNA under general anesthesia, the gradual reduction in parasympathetic modulation of SAN during the procedure was assessed by extracardiac right vagal nerve stimulation (ECVS). The response to ECVS was quantified by the ratio of the maximum P-P interval (induced by ECVS) and the baseline SR cycle length (MaxPPratio). The ECVS was performed repeatedly after partial ablation steps, and therefore several pairs of DeltaSR and MaxPPratio values were obtained in the course of the single procedure. A MaxPPratio &lt;1.5 was arbitrarily chosen as the criterion of significant attenuation of vagally induced responses. The optimum dichotomy of Delta-SR for the prediction of the MaxPPratio &lt;1.5 was found according to the criterion of the minimum distance of the ROC curve from the point (0; 1).

Results

The study included 64 patients (mean age: 42 ± 16 years, 48% men). A total of 188 intraprocedural pairs of DeltaSR and MaxPPratio (2.9 ± 2.1 pairs per procedure) covering the wide distribution of their values (19 ± 14 bpm for DeltaSR and 2.9 ± 2.8 for MaxPPratio) were obtained. One half of ECVS tests (51%) met the criterion of MaxPPratio &lt;1.5. In the analysis of receiver operating characteristic, DeltaSR as a predictor of significantly reduced parasympathetic modulation of SAN showed an area under the curve (AUC) of 0.69 with 95% confidence interval (CI) of 0.62 - 0.77 (Figure). The optimum cut-off (DeltaSR ≥20 bpm) had a sensitivity (SENS), specificity (SPEC), positive (PPV), and negative predictive value (NPV) of 61%, 78%, 75%, and 66%, respectively.

Conclusion

Acceleration of SR during CNA is not a relevant surrogate of significantly reduced parasympathetic modulation of SAN. Elimination or significant suppression of responses of SAN to ECVS serves as an excellent procedural endpoint that might contribute to the favorable clinical outcome of the CNA.

Acute change of cardiac autonomic regulations after thermal and non-thermal pulmonary vein ablation

Funding Acknowledgements

Type of funding sources: None.

Background

Pulmonary vein isolation (PVI) by thermal energy (radiofrequency energy or cryoenergy) results in collateral ganglionic plexi ablation. On the contrary, pulsed electric field (PEF) energy presumably spares neural tissue.

Purpose

We investigated and compared the effect of PVI on parasympathetic input into the sinus node (SAN) and AV node (AVN) when four different ablation strategies were used.

Methods

A study enrolled 49 patients who underwent PVI in general anesthesia (age: 57 ± 13 years, 71% males). In 17 patients, point-by-point radiofrequency energy delivery by the irritated-tip catheter was used for ablation while 7 patients were ablated using a second-generation cryoballoon catheter. In 7 patients, PEF energy was delivered using a single-shot Farawave catheter while 18 patients were ablated using Sphere9 lattice-tip catheter (Affera, Inc.); both subgroups with manufacturer-specific PEF settings. Before and after PVI, the responsiveness of the SAN and AVN was assessed by extracardiac vagal nerve stimulation (ECVS) via a diagnostic catheter in the right internal jugular vein. Five-second stimulation trains were delivered with a frequency of 50 Hz, pulse width of 0.05 ms, and output of 1 V/kg (&lt;70V) both in sinus rhythm and during atrial pacing. Substantial reduction of response to ECVS was arbitrarily defined as a maximum induced pause of &lt;1.5 seconds.

Results

At baseline, physiological response to ECVS (long sinus arrest and/or AV block) was demonstrated. After PVI, a substantial reduction of SAN response was observed in 21/24 (88%) patients after thermal PVI and 7/25 (25%) patients after non-thermal PVI (P = 0.0001). Similarly, a substantial reduction of AVN response was observed in 21/24 (88%) patients after thermal PVI and 9/25 (36%) patients after non-thermal PVI (P = 0.0003). The Figure shows on the continuous scale the post-PVI pauses in sinus rhythm (maximum P-P interval) and atrial pacing (maximum R-R interval) induced by ECVS.

Conclusion

Vagal responses of SAN and AVN are preserved in most AF patients after non-thermal PVI. This contrasts with the much stronger effect of thermal PVI. Whether this may influence the clinical outcome of AF ablation procedures remains to be investigated in future studies.

Stereotactic body radiotherapy for refractory ventricular tachycardia: the overall czech experience

Funding Acknowledgements

Type of funding sources: None.

Background

Catheter ablation (CA) is a well-established treatment strategy for the management of drug-refractory ventricular tachycardia (VT) in patients with structural heart disease. Stereotactic body radiotherapy (SBRT) was proposed recently as a treatment option for cases of failed CA.

Purpose

This study reports overall experience with the SBRT from two Czech centers.

Methods

Since 2014, we enrolled consecutive patients who underwent at least one prior CA for recurrent scar-related VT and had subsequent VT recurrences due to inaccessible substrate. Single-session SBRT for VT was performed without the use of general anesthesia or sedation. A dose of 25 Gy was delivered.

Results

The study investigated 33 patients (3 women) with a mean age of 66 ± 9 years. Underlying heart disease was ischemic (58%) and nonischemic (39%) cardiomyopathy; one patient had large cardiac fibroma. The mean left ventricular ejection fraction was 31 ± 8%. Seventy-six percent of patients were on amiodarone. Before SBRT, they underwent a median of 2 (IQR: 1-3; range: 1-5) CA that included epicardial access in 42% of patients.

Following SBRT with a planned target volume of 42.6 ± 22.8 ml, the immediate effect was not observed in any patient, VT burden gradually decreased over weeks or months.

Seventeen (52%) patients died (2 of them suddenly) during the mean follow up of 29 ± 23 months mainly due to the progression of heart failure (Figure 1). One patient died due to bleeding associated with esophagopericardial fistula that developed 9 months after SBRT.

Overall, the number of DC shocks after a single procedure decreased significantly from 0.9 ± 1.9 per month in the period of 6 months before SBRT to 0.1 ± 0.3 per month in the period of 6-12 months after SBRT (P=0.008, Figure 2). However, 14 patients (42%) had to undergo additional CA due to VT recurrences at a mean interval of 13 ± 14 months after SBRT. Three patients underwent repeated SBRT (after 3, 29, and 38 months), which was successful in 2 of them.

Conclusions

SBRT in patients with refractory VT is feasible but the long-term mortality after the procedure is high and reflects mainly the severity of the underlying disease. The treatment effect of SBRT is delayed and additional CA is often necessary for VT suppression. At present, SBRT should be offered as only a bailout procedure for otherwise intractable VT.

Ultrasound-guided femoral venipuncture for catheter ablation of atrial fibrillation: clinical benefit

Funding Acknowledgements

Type of funding sources: None.

Background

The most frequent complications of catheter ablation for atrial fibrillation (AF) are related to vascular access.

Purpose

Vascular complication rates of ultrasound-guided venipuncture (USGV) were analyzed and compared to historical controls (CTRL) with an anatomical landmark-guided approach.

Methods

The study cohort included 4646 consecutive patients (2330 and 2316 patients in USGV and CTRL groups, respectively). Clinical characteristics were as follows: age of 61±10 years, 67% males, 66% paroxysmal AF, CHA2DS2-VASc score of 2.0±1.4, 27% reablation, and procedure time of 208±69 min. Both femoral veins were cannulated with 2 and 2 sheaths (7, 11, and 2x 8.5 French) in the majority (&gt;95%) of procedures. Major complications were defined as those requiring intervention (surgery, thrombin injection, or transfusion), or hematoma/bleeding with hemoglobin drop &gt;30g/l, or condition prolonging hospitalization and/or resulting in re-hospitalization. They were extracted from the institutional tracking system for complications of invasive procedures and by a review of medical reports within the first 3 months of follow-up.

Results

There were 32 (1.38%) vs. 62 (2.66%) major complications related to vascular access in USGV and CTRL groups, respectively (Yates corrected Chi-square P=0.003), i.e. relative reduction of -48% in the USGV group. Surgical intervention was needed in 6 (0.26%) vs. 18 (0.77%) patients, respectively (Fisher exact test P=0.02), i.e. relative reduction of -64% in the USGV group. The differences remained significant after adjustment for baseline clinical characteristics. Multivariate analysis revealed that USGV strategy (P=0.0005), male gender (P=0.003), and less advanced age (P=0.0002) were significantly associated with lower complication rates.

Conclusions

USGV was associated with a statistically significant reduction of major vascular complications after catheter ablation for AF. This strategy also decreased the need for surgical correction of vascular complications. Ultrasound guidance can be recommended to improve the safety of femoral venous access.

Anatomically-guided cardioneuroablation for recurrent neurally mediated syncope

Funding Acknowledgements

Type of funding sources: None.

Background

Cardioneuroablation (CNA) has been proposed as a new therapeutic approach in selected patients with recurrent neurally mediated syncope and documented cardioinhibitory component.

Purpose

We report on procedural data and clinical outcomes of consecutive patients who underwent anatomically-guided CNA at our center in the period of 2014 - 2021.

Methods

A study investigated 145 otherwise healthy patients (age: 40 ± 14 years, 56% males) with recurrent reflex syncope and the physiological result of the atropine test. Biatrial radiofrequency (RF) ablation was performed under general anesthesia by irrigated-tip catheter at empirical sites of ganglionated plexi (GP) with the navigation by CARTO-3 system and intracardiac echocardiography. Anterior right GP and posteromedial left GP were always targeted to modulate the innervation of both sinoatrial (SAN) and atrioventricular (AVN) nodes, irrespective of clinical manifestation of the disease. The loss of responsiveness of both nodes to extracardiac vagus nerve stimulation was the procedural endpoint. Right vagus or bilateral vagus nerve stimulation was used in 86% and 54% of procedures, respectively.

Results

Enrolled patients had documented cardioinhibitory disorder of SAN (59%), AVN (30%), or both nodes (11%). CNA (duration: 157 ± 31 min; RF time: 15 ± 6 min; radiation dose: 84 ± 135 µGy.m²) resulted in sinus rate acceleration by 28 ± 12 bpm, shortening of AH interval by 15 ± 31 ms, an increase of Wenckebach point by 28 ± 33 bpm, shortening of AVN effective refractory period by 110 ± 115 ms, and sinus node recovery time by 508 ± 666 ms. During a median follow up of 26 (IQR: 12-39) months, CNA was repeated in 9 patients and is scheduled in 3 other (total 8%). Pacemaker was implanted only in 4 (3%) patients after single (n = 2) or repeated CNA (n = 2). Corresponding Kaplan-Meier curves are provided in the Figure. Any-syncope-free survival is comparable to that reported in active arms of historical and recent pacemaker studies.

Conclusions

CNA is a reasonably effective treatment option for patients with functional cardioinhibitory syncope. CNA can be performed by anatomically-guided ablation at empirical GP sites. Our study corroborates the clinical utility of CNA as a viable alternative to pacemaker implant in selected patients.

Case Report: Repeated Stereotactic Radiotherapy of Recurrent Ventricular Tachycardia: Reasons, Feasibility, and Safety

Stereotactic body radiotherapy (SBRT) has been reported as an attractive option for cases of failed catheter ablation of ventricular tachycardia (VT) in structural heart disease. However, even this strategy can fail for various reasons. For the first time, this case series describes three re-do cases of SBRT which were indicated for three different reasons. The purpose in the first case was the inaccuracy of the determination of the treatment volume by indirect comparison of the electroanatomical map and CT scan. A newly developed strategy of co-registration of both images allowed precise targeting of the substrate. In this case, the second treatment volume overlapped by 60% with the first one. The second reason for the re-do of SBRT was an unusual character of the substrate–large cardiac fibroma associated with different morphologies of VT from two locations around the tumor. The planned treatment volumes did not overlap. The third reason for repeated SBRT was the large intramural substrate in the setting of advanced heart failure. The first treatment volume targeted arrhythmias originating in the basal inferoseptal region, while the second SBRT was focused on adjacent basal septum without significant overlapping. Our observations suggested that SBRT for VT could be safely repeated in case of later arrhythmia recurrences (i.e., after at least 6 weeks). No acute toxicity was observed and in two cases, no side effects were observed during 32 and 22 months, respectively. To avoid re-do SBRT due to inaccurate targeting, the precise and reproducible strategy of substrate identification and co-registration with CT image should be used.

Management of ventricular arrhythmias in heart failure: Current perspectives

Congestive heart failure (HF) is a progressive affliction defined as the inability of the heart to sufficiently maintain blood flow. Ventricular arrhythmias (VAs) are common in patients with HF, and conversely, advanced HF promotes the risk of VAs. Management of VA in HF requires a systematic, multimodality approach that comprises optimization of medical therapy and use of implantable cardioverter-defibrillator and/or device combined with cardiac resynchronization therapy. Catheter ablation is one of the most important strategies with the potential to abolish or decrease the number of recurrences of VA in this population. It can be a curative strategy in arrhythmia-induced cardiomyopathy and may even save lives in cases of an electrical storm. Additionally, modulation of the autonomic nervous system and stereotactic radiotherapy have been introduced as novel methods to control refractory VAs. In patients with end-stage HF and refractory VAs, an institution of the mechanical circulatory support device and cardiac transplant may be considered. This review aims to provide an overview of current evidence regarding management strategies of VAs in HF with an emphasis on interventional treatment.

Acute efficacy of contiguous versus temporally discontiguous point-by-point radiofrequency pulmonary vein isolation in patients with paroxysmal atrial fibrillation: a randomized study

PURPOSE

Durable pulmonary vein (PV) isolation (PVI) determines the clinical success of catheter ablation for atrial fibrillation. In this randomized study, we investigated whether the temporally discontiguous deployment of ablation lesions adversely affected the acute efficacy of PVI.

METHODS

Thirty-six consecutive patients with drug-refractory paroxysmal atrial fibrillation (aged 59 ± 11, 58% males) were randomized 1:1 to either discontiguous (D-PVI) or contiguous (C-PVI) encircling radiofrequency (RF) lesions around ipsilateral PVs. A contact force-sensing catheter was used targeting a final interlesion distance < 6 mm and the ablation index of 400-450 (anterior wall) and 300-350 (posterior wall). The study endpoint was defined as failure of first-pass PVI or acute PV reconnection during a waiting time (> 30 min) followed by adenosine challenge.

RESULTS

The total RF time, number of RF lesions, and mean interlesion distance were comparable in both groups. Total endpoint rates were 1/36 (3%) in the D-PVI vs 4/36 (11%) in the C-PVI groups; P = 0.34 for superiority, P = 0.008 for non-inferiority. Adenosine-induced reconnection of right PVs was the only endpoint in the D-PVI group. In the C-PVI group, first-pass PVI failed in 2 right PVs and spontaneous reconnection occurred in 2 other circles (left and right PVs).

CONCLUSION

Temporally discontiguous deployment of RF lesions is not associated with lower procedural PVI efficacy when strict criteria for interlesion distance and ablation index are applied. The development of local edema around each ablation site does not prevent effective RF lesion formation at adjacent positions.

TRIAL REGISTRATION

clinicaltrials.gov (NCT03332862).

Temperature-Controlled Catheter Ablation for Paroxysmal Atrial Fibrillation: the QDOT-MICRO Workflow Sttudy

Background

A novel QDOT MICRO (Biosense Webster, Inc., Irvine, CA) catheter with optimized temperature control and microelectrodes was designed to incorporate real-time temperature sensing with contact force detection and microelectrodes to streamline ablation workflow. The QDOT-MICRO feasibility study evaluated the workflow, performance, and safety of temperature-controlled catheter ablation in patients with symptomatic paroxysmal atrial fibrillation with conventional ablation setting.

Methods

This was a non-randomized, single-arm, first-in-human study. The primary outcome was pulmonary vein isolation (PVI), confirmed by entrance block after adenosine and/or isoproterenol challenge. Safety outcomes included incidences of early-onset primary adverse events (AEs) and serious adverse device effects (SADEs). Device performance was evaluated via physician survey.

Results

All evaluated patients (n = 42) displayed 100% PVI. Two primary AEs (4.8%) were reported: 1 pericarditis and 1 vascular pseudoaneurysm. An additional SADE of localized infection was reported in 1 patient. No stroke, patient deaths, or other unanticipated AEs were reported. Average power delivered was 32.1±4.1 W, with a mean temperature of 40.8°C±1.6°C. Mean procedure (including 20-minute wait), fluoroscopy, and radiofrequency application times were 129.8, 6.7, and 34.0 minutes, respectively. On device performance, physicians reported overall satisfactory performance with the new catheter, with highest scores for satisfaction and usefulness of the temperature indicator.

Conclusions

Initial clinical experience with the novel catheter showed 100% acute PVI success and acceptable safety and device performance in temperature-controlled ablation mode. There were no deaths, stroke, or unanticipated AEs. Fluoroscopy and procedural times were short and similar or better than reported for prior generation catheters.

HeartMate 3: new challenges in ventricular tachycardia ablation

AIM

To describe clinical characteristics, procedural details, specific challenges, and outcomes in patients with HeartMate3™ (HM3), a left ventricular assist device system with a magnetically levitated pump, undergoing ventricular tachycardia ablation (VTA).

METHODS AND RESULTS

Data were collected from patients with an HM3 system who underwent VTA in seven tertiary centres. Data included baseline patient characteristics, procedural data, mortality, and arrhythmia-free survival. The study cohort included 19 patients with cardiomyopathy presenting with ventricular tachycardia (VT) (53% with VT storm). Ventricular tachycardias were induced in 89% of patients and a total of 41 VTs were observed. Severe electromagnetic interference was present on the surface electrocardiogram. Hence, VT localization required analysis of intra-cardiac signals or the use of filter in the 40-20 Hz range. The large house pump HM3 design obscured the cannula inflow and therefore multi imaging modalities were necessary to avoid catheter entrapment in the cannula. A total of 32 VTs were mapped and were successfully ablated (31% to the anterior wall, 38% to the septum and only 9% to the inflow cannula region). Non-inducibility of any VT was reached in 11 patients (58%). Over a follow-up of 429 (interquartile range 101-692) days, 5 (26%) patients underwent a redo VT ablation due to recurrent VTA and 2 (11%) patients died.

CONCLUSIONS

Ventricular tachycardia ablation in patients with HM3 is feasible and safe when done in the appropriate setup. Long-term arrhythmia-free survival is acceptable but not well predicted by non-inducibility at the end of the procedure.

Left Atrial Appendage Closure versus Non-Warfarin Oral Anticoagulation in Atrial Fibrillation: 4-Year Outcomes of PRAGUE-17

BACKGROUND

The PRAGUE-17 trial demonstrated that left atrial appendage closure (LAAC) was non-inferior to non-warfarin oral anticoagulants (NOAC) for preventing major neurological, cardiovascular or bleeding events in high-risk patients with atrial fibrillation (AF).

OBJECTIVE

To assess the pre-specified long-term (4-year) outcomes in PRAGUE-17.

METHODS

PRAGUE-17 was a randomized non-inferiority trial comparing percutaneous LAAC (Watchman or Amulet) with NOACs (95% apixaban) in non-valvular AF patients with a history of cardioembolism, clinically-relevant bleeding, or both CHA₂DS₂-VASc > 3 and HASBLED > 2. The primary endpoint was a composite of cardioembolic events (stroke, transient ischemic attack, or systemic embolism), cardiovascular death, clinically-relevant bleeding, or procedure/device-related complications (LAAC group only). The primary analysis was modified intention-to-treat (mITT).

RESULTS

We randomized 402 AF patients (201 per group, age 73.3±7.0 years, 65.7% male, CHA₂DS₂-VASc 4.7+1.5, HASBLED 3.1+0.9). After 3.5 years median follow-up (1,354 patients-years), LAAC was non-inferior to NOAC for the primary endpoint by mITT (subdistribution hazard ratio[sHR] 0.81, 95% CI 0.56-1.18; p=0.27; p for non-inferiority=0.006). For the components of the composite endpoint, the corresponding sHRs (and 95% CIs) were 0.68 (0.39-1.20; p=0.19) for cardiovascular death, 1.14 (0.56-2.30; p=0.72) for all-stroke/TIA, 0.75 (0.44-1.27; p=0.28) for clinically-relevant bleeding, and 0.55 (0.31-0.97; p=0.039) for non-procedural clinically-relevant bleeding. The primary endpoint outcomes were similar in the per-protocol [sHR 0.80 (95% CI 0.54-1.18), p=0.25] and on-treatment [sHR 0.82 (95% CI 0.56-1.20), p=0.30] analyses.

CONCLUSION

In long-term follow-up of PRAGUE-17, LAAC remains non-inferior to NOACs for preventing major cardiovascular, neurological or bleeding events. Furthermore, non-procedural bleeding was significantly reduced with LAAC.

Mutation in a non-desmosomal gene is associated with poor outcome of endo-epicardial ventricular tachycardia ablation in patients with nonischaemic cardiomyopathy

Background

Nonischaemic cardiomyopathy (NICM) represents a heterogenic disorder with a variable arrhythmogenic substrate. Its location is often epicardial and catheter ablation in this location proved to be an effective therapeutic modality in NICM patients with recurrent ventricular tachycardias (VTs).

Purpose

To determine the impact of the type of genetic mutation on the long-term outcome of endo-epicardial ablation in patients with NICM.

Methods

We investigated 82 patients (age 47±15 years, 10 women) with NICM who underwent endo-epicardial ablation for frequent VTs. Of them, 59% had a history of failed endocardial ablation. Patients had a left ventricular ejection fraction of 44±14% and all were implanted with cardioverter-defibrillator. One hundred candidate genes were examined using the new generation sequencing technique.

Results

Mutation in genes coding desmosomal complex (genes: PKP2, DSC, DSP, and DSG) was found in 30% of patients (“desmosomal” group). In 23% of patients, other gene mutations (genes: LMNA/C, MYH7, DES, TTN, RYR2, TPM1, MYPN, FLNC, and SCN5A) were detected (“non-desmosomal” group). In 46% of subjects no pathogenic mutation could be identified (“none” group). During a mean follow up of 34±33 months, patients in the “non-desmosomal” group were at significantly higher risk of VT recurrence and death/heart transplant compared to patients in the “desmosomal” group (Figure 1).

Conclusion

Potentially pathogenic mutation can be detected in about half of patients with NICM undergoing endo-epicardial VT ablation. Most commonly, mutations can be found in genes coding desmosomal complex and the endo-epicardial ablation is then associated with a satisfactory low VT recurrence rate and excellent survival in the long-term. On the other hand, patients with a mutation in non-desmosomal genes have poor outcomes despite endo-epicardial ablation.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Supported by Ministry of Health of the Czech Republic, grant nr. NV18-02-00237 Figure 1

Temporary prolongation of corrected QT interval after cardioneuroablation for functional bradyarrhythmias

Background

There are controversial reports on QT interval response to ganglionic plexi ablation that are selectively targeted during cardioneuroablation (CNA) or occurs as collateral lesion during left atrial ablation procedures. Both shortening or prolongation of the heart-rate corrected QT interval (QTc) with therapeutic or safety implications were described.

Purpose

In this retrospective study, we investigated longitudinal changes of QTc after CNA.

Methods

The study included 108 patients (age: 39±12 years, 60% males) who underwent biatrial cardioneuroablation (radiofrequency time: 15.5±6.7 min) for symptomatic functional bradyarrhythmias. Surface ECG examinations were performed on the day before the CNA (N=108), 1 hour after the CNA (N=106), on the 1st post-ablation day (N=50), at the 3-month (N=99), and 1-year (N=63) follow-up visits. Automated measurements of QT interval were employed for the analysis. Four formulas (Bazett, Framingham, Fridericia, and Hodges) were used for the correction of QT interval to instant heart rate.

Results

QTc significantly prolonged immediately after the CNA with rapid return to baseline values (Figure and Table). This was particularly valid for QT correction by Framingham formula (and similarly for Fridericia and Hodges formulas). The QTc by Bazett formula, which is known to overestimate QT at higher heart rates, returned to baseline more slowly and incompletely. Several mechanisms may contribute to observed QTc dynamics: (1) direct effect of autonomic denervation with recovery phenomenon; (2) QT hysteresis with an extremely long time constant; or (3) artifact due to suboptimum QT correction to a substantial change of heart rate.

Conclusions

The study suggests that CNA produces acute prolongation of QTc interval with rapid decay and virtual normalization in 3 months. CNA in otherwise healthy subjects is not likely associated with substantial long-term risk of long-QT-associated arrhythmias. In the same way, we cannot confirm earlier observations of clinically significant QTc shortening effect of ganglionated plexi ablation.

Funding Acknowledgement

Type of funding sources: None. Figure 1Table 1

Acute change in parasympathetic cardiac innervation after pulmonary vein isolation by pulse-field and radiofrequency energy

Background

In patients with atrial fibrillation (AF), pulmonary vein isolation (PVI) by radiofrequency (RF) energy is associated with a significant change of cardiac autonomic regulations due to collateral ganglionic plexi ablation. Pulse-field (PF) ablation energy presumably spares neural tissue.

Purpose

We compared the effect of PVI by PF and RF energy on cardiac autonomic function.

Methods

A study enrolled 23 patients who underwent PVI in general anaesthesia. In 12 patients, a novel lattice-tip catheter and PF energy were used for ablation while 11 patients were ablated using a conventional irrigated-tip catheter and RF energy. The response of the sinus node (SAN) and atrioventricular node (AVN) to extracardiac high-frequency vagal stimulation (ECVS) was tested before and after PVI (via right internal jugular vein; stimulation frequency of 50 Hz; pulse width of 0.05 ms; output of 1 V/kg (&lt;70V); train duration of 5 s).

Results

At baseline, physiological massive response to ECVS (sinus arrest and/or AV block) was demonstrated in the majority of patients. After PVI, complete loss of autonomic response of the SAN in 11/11 (100%) and 3/12 (25%) patients (p=0.003), and the AVN in 9/11 (82%) and 3/12 (25%) patients (p=0.01) was observed in RF and PF groups, respectively. The figure shows the maximum duration of the pause in sinus rhythm (maximum P-P interval) and AVN block (maximum R-R interval during atrial pacing) induced by ECVS after PVI.

Conclusion

Cardiac vagal response is preserved in a considerable proportion of AF patients after PF ablation which is in contrast with a significantly stronger effect of RF energy. This may influence the clinical outcome of AF ablation procedures.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Institute for Clinical and Experimental Medicine, Prague

Anatomical variants of the cavotricuspid isthmus in patients undergoing catheter ablation for atrial flutter and/or atrial fibrillation

Background

We evaluated the differences in the anatomy of the cavotricuspid isthmus (CTI) by assessing image loops provided by intracardiac echocardiography (ICE) in patients who underwent ablation for atrial flutter and/or atrial fibrillation.

Purpose

CTI is an essential component of the reentrant circle in isthmus–dependent atrial flutter (CTI-AFL) and a target for catheter ablation. In some patients, CTI anatomy may be responsible for a difficult procedure. The aim of this study is to describe in details the anatomical variants of this structure.

Methods

We included a group of 138 patients, who underwent cardiac ablation for atrial flutter and/or atrial fibrillation between August 2020 and January 2021. Intracardiac echocardiography was employed during the intervention to evaluate the morphology of CTI. Analysis was focused on size, shape, presence of sub-eustachian pouch (excavation more than 5 mm) or presence of prominent Eustachian ridge (ER, embryologic remnant of the valve of the IVC) and mobility of the structure.

Results

The length of CTI measured during ventricular systole averaged at 38,4mm (min 22,5mm, max 60mm). The most frequent pattern was a flat CTI without sub-eustachian excavation or with excavation less than 5mm (71 patients; 51.4%). A pouch (excavation more than 5mm) was observed in 41 pts (29.7%), where the deepest pouch reached 10,5mm. Prominent ER was present in 58 pts (42%). The remaining 26 of CTIs (18.8%) were classified in the “unclassifiable” category with deviations from common anatomic variants - substantial convexity, pronounced trabeculation of isthmus or double pouch. We observed 14 CTIs (10.1%), where the structure was partially or in full extent detached from the diaphragm, sliding during cardiac contractions. In addition to the described morphology, Chiari's network was observed in 18 pts (13%).

In reference to mobility, 53 pts (38.4%) presented with hypermobile CTI with a difference in size of more than 1/3 between the diastole and systole.

Moreover, we looked into differences of CTI related to BMI, left atrial volume index (LAVi) and ejection fraction of the left ventricle. A positive correlation was found between LVEF and mobility of CTI. Hypermobile CTI was present in 42.2% of pts with normal LVEF compared to only 18.9% of pts with reduced EF (EF less than 50%). Similar results were observed in pts with non-dilated LA, where hypermobile CTI was present in 51.9% of pts compared to only 35.1% of pts with dilated LA with LAVi &gt;28 ml/m2 (see table below).

Conclusions

We observed a substantial differences in the anatomy of the CTI, which could play an important role in catheter ablation of this structure. Besides the prominent ER, significant sub-eustachian pouch and hypermobility appear to be variants predisposing to difficult ablation.

Funding Acknowledgement

Type of funding sources: None. CTI variants related to EFLV, BMI, LAViCTI detached from the diaphragm

Radiation-Induced Changes in Ventricular Myocardium After Stereotactic Body Radiotherapy for Recurrent Ventricular Tachycardia

Stereotactic body radiotherapy (SBRT) has been suggested as a promising therapeutic alternative in cases of failed catheter ablation for recurrent ventricular tachycardias (VTs) in patients with structural heart disease. This case series is the first postmortem immunohistochemical analysis of morphologic changes in the myocardium early and late after SBRT. The present findings are in line with experimental observations on apoptosis followed by fibrosis. This may explain why the effect of SBRT on VT is not predominantly immediate. Together with observation of early recurrences after SBRT for VT, these data suggest that this strategy may have rather delayed antiarrhythmic effects.