Contemporary catheter ablation of complex atrial tachycardias after prior atrial fibrillation ablation: pulsed field vs. radiofrequency current energy ablation guided by high-density mapping

AIMS

Catheter ablation (CA) of post-ablation left atrial tachycardias (LATs) can be challenging. So far, pulsed field ablation (PFA) has not been compared to standard point-by-point radiofrequency current (RFC) energy for LAT ablation. To compare efficacy of PFA vs. RFC in patients undergoing CA for LAT.

METHODS AND RESULTS

Consecutive patients undergoing LAT-CA were prospectively enrolled (09/2021-02/2023). After electro-anatomical high-density mapping, ablation with either a pentaspline PFA catheter or RFC was performed. Patients were matched 1:1. Ablation was performed at the assumed critical isthmus site with additional ablation, if necessary. Right atrial tachycardia (RAT) was ablated with RFC. Acute and chronic success were assessed. Fifty-six patients (n = 28 each group, age 70 ± 9 years, 75% male) were enrolled.A total of 77 AT (n = 67 LAT, n = 10 RAT; 77% macroreentries) occurred with n = 32 LAT in the PFA group and n = 35 LAT in the RFC group. Of all LAT, 94% (PFA group) vs. 91% (RFC group) successfully terminated to sinus rhythm or another AT during ablation (P = 1.0). Procedure times were shorter (PFA: 121 ± 41 vs. RFC: 190 ± 44 min, P < 0.0001) and fluoroscopy times longer in the PFA group (PFA: 15 ± 9 vs. RFC: 11 ± 6 min, P = 0.04). There were no major complications. After one-year follow-up, estimated arrhythmia free survival was 63% (PFA group) and 87% (RFC group), [hazard ratio 2.91 (95% CI: 1.11-7.65), P = 0.0473].

CONCLUSION

Pulsed field ablation of post-ablation LAT using a pentaspline catheter is feasible, safe, and faster but less effective compared to standard RFC ablation after one year of follow-up. Future catheter designs and optimization of the electrical field may further improve practicability and efficacy of PFA for LAT.

Pulsed-field versus cryoballoon ablation for atrial fibrillation-Impact of energy source on sedation and analgesia requirement

INTRODUCTION

Pulsed field ablation (PFA) represents a novel, nonthermal energy modality that can be applied for single-shot pulmonary vein isolation (PVI) in atrial fibrillation (AF). Comparative data with regard to deep sedation to established single-shot modalities such as cryoballoon (CB) ablation are scarce. The aim of this study was to compare a deep sedation protocol in patients receiving PVI with either PFA or CB.

METHODS

Prospective, consecutive AF patients undergoing PVI with a pentaspline PFA catheter were compared to a retrospective CB-PVI cohort of the same timeframe. Study endpoints were the requirements of analgesics, cardiorespiratory stability, and sedation-associated complications.

RESULTS

A total of 100 PVI patients were included (PFA n = 50, CB n = 50, mean age 66 ± 10.6, 61% male patients, 65% paroxysmal AF). Requirement of propofol, midazolam, and sufentanyl was significantly higher in the PFA group compared to CB [propofol 0.14 ± 0.04 mg/kg/min in PFA vs. 0.11 ± 0.04 mg/kg/min in CB (p = .001); midazolam 0.00086 ± 0.0004 mg/kg/min in PFA vs. 0.0006295 ± 0.0003 mg/kg/min in CB (p = .002) and sufentanyl 0.0013 ± 0.0007 µg/kg/min in PFA vs. 0.0008 ± 0.0004 µg/kg/min in CB (p < .0001)]. Sedation-associated complications did not differ between both groups (PFA n = 1/50 mild aspiration pneumonia, CB n = 0/50, p > .99). Nonsedation-associated complications (PFA: n = 2/50, 4%, CB: n = 1/50, 2%, p > .99) and procedure times (PFA 75 ± 31, CB 84 ± 32 min, p = .18) did not differ between groups.

CONCLUSIONS

PFA is associated with higher sedation and especially analgesia requirements. However, the safety of deep sedation does not differ to CB ablation.

Left Atrial Posterior Wall Isolation with Pulsed Field Ablation in Persistent Atrial Fibrillation

BACKGROUND

Left atrial posterior wall isolation (LAPWI) may improve rhythm control in addition to pulmonary vein isolation (PVI) in persistent atrial fibrillation (persAF) patients undergoing catheter ablation (CA). However, LAPWI may be challenging when using thermal energy sources.

OBJECTIVE

This study aimed to investigate the efficacy and safety of LAPWI performed by non-thermal pulsed field ablation (PFA) in CA for persAF.

METHODS

Consecutive persAF patients from two German centers were prospectively enrolled. There were two study cohorts: (1) the LAPWI cohort, which included PFA-guided (re-)PVI with LAPWI for first-time and/or repeat ablation procedures; and (2) a comparative persAF cohort with a PFA PVI-only approach without LAPWI for first-time ablation within the same timeframe. Patients were followed up by routine Holter ECGs.

RESULTS

In total, 79 persistent AF patients were included in the study: 59/79 patients were enrolled in the LAPWI cohort, including 16/59 index (27%) and 43/59 repeat ablation procedures (73%). Sixteen patients (16/79; 21%) were in the PVI-only cohort without LAPWI. Of the patients treated with LAPWI, procedure time and fluoroscopy time was 91 ± 30 min and 15 ± 7 min, respectively. The acute PVI rate was 100% in all first-time ablation patients (32 patients (16 PVI only, 16 PVI plus LAPWI), 196/196 PVs). Of the 43 re-do patients in the LAPWI cohort, re-PVI was necessary in 33% (14/43) of patients (27 PVs; 1.9 PV per-patient); in 67% (29/43), all PVs were isolated, and antral ablation of the PV ostia was performed in 48% (14/29). LAPWI was performed successfully in all 59 (100%) patients of the LAPWI cohort. Two minor complications occurred. No esophageal lesion was detected in the LAPWI cohort (n = 33/59 (56%) patients underwent endoscopy). After 354 ± 197 days of follow-up, freedom from atrial arrhythmias was 79.3% (95-CI: 62-95%) in the complete LAPWI cohort (n = 14/59 (24%) on AAD: class Ic n = 9, class III n = 5). There was no difference regarding acute procedural and clinical outcome compared to the PVI-only cohort.

CONCLUSION

LAPWI guided by PFA is feasible and safe in patients undergoing CA for persAF and shows favorable outcomes. In the context of durable PVI, PFA-guided LAPWI may be an effective adjunctive treatment option.

Pulsed field ablation in patients with complex consecutive atrial tachycardia in conjunction with ultra-high density mapping: Proof of concept

INTRODUCTION

Catheter-ablation (CA) of consecutive left atrial tachycardias (LAT) can be challenging. Pulsed field ablation (PFA) yields a novel nonthermal CA technology for treatment of atrial fibrillation (AF). There is no data regarding PFA of LAT. This study sought to investigate PFA of consecutive LAT following prior CA of AF.

METHODS

Consecutive patients with LAT underwent ultrahigh-density (UHDx) mapping. Subsequent to identification of the AT mechanism, PFA was performed at the assumed critical sites for LAT maintenance. Continuous ablation lines were performed if required and evaluated with pre- and post-PFA HDx-mapping.

RESULTS

Fifteen patients (age 70 ± 10, male 73%) who underwent 3.6 ± 2 prior AF-CA procedures were included. The total mean procedure and fluoroscopy times were 141 ± 43 and 18 ± 10 min, respectively. All 19 of 19 (100%) LAT were successfully ablated with PFA. Two AT located at the right atria required RF-ablation. LAT were identified as localized reentry (n = 1) and macro-reentry LAT (n = 18) and targeted with PFA. All LAT terminated with PFA either to sinus rhythm (9/15) or a secondary AT (6/15 and subsequently to SR); 63% (12/19) terminated with the first PFA-application. All lines (13 roof, 11 anterior, 1 mitral) were blocked. LA-posterior-wall isolation (LAPWI) was successfully achieved when performed (10/10). AF/AT free survival was 80% (12/15) after 153 [88-207] days of follow-up. No procedure-related complications occurred.

CONCLUSION

PFA of consecutive LAT is feasible and safe. Successful creation of ablation lines and LAPWI can be achieved in a short time. PFA may offer the opportunity for effective ablation of atrial arrhythmias beyond AF.

Safety and efficacy of catheter ablation for atrial fibrillation in the very elderly

Background

The incidence and prevalence of atrial fibrillation (AF) increases with age. With an ageing general population, a 2.3-fold rise in AF prevalence is expected. Catheter ablation has emerged as an effective treatment option for rhythm control therapy. However, very elderly patients (≥80 years old) have been excluded in landmark clinical trials. Current data regarding the safety and efficacy of catheter ablation in the very elderly is therefore sparse.

Purpose

Due to the growing demand to manage AF in an increasingly ageing population, we investigated the safety and efficacy of catheter ablation in this particular patient population.

Methods

Patients with symptomatic paroxysmal, persistent and long-standing persistent AF aged ≥80 years undergoing catheter ablation, including first and re-ablation procedures in a single centre, were analysed retrospectively. Catheter ablation involved pulmonary vein isolation (PVI) using radiofrequency, cryoballoon and pulsed field ablation as energy sources. Re-ablation procedures included re-PVI and consecutive atrial tachycardia ablation including atrial lines and/or ablation of complex fractionated atrial electrograms (CFAE) in persistent AF. Endpoints included acute procedural success (complete isolation of pulmonary veins and/or non-inducibility in the case of atrial tachycardia), major complications and early arrhythmia-recurrence.

Results

A total of eighty-eight patients (mean age 83.1±1.9 years, mean CHA2DS2-VASc-Score 4.4±1, mean left ventricular ejection fraction 56.7±7%, direct oral anticoagulation 92.1%, vitamin-K antagonists 7.9%) were included from January 2021 to October 2021. Fifty cases (56.8%) involved PVI as an index procedure (radiofrequency 58%, n=29/50, cryoballoon 36%, n=18/50, pulsed field ablation 6%, n=3/50). Thirty-eight procedures (43.2%) involved re-ablation procedures (Re-PVI 60.5%, n=23/38, linear lesions 65.8%, n=25/38, atrial tachycardia ablation 26.3%, n=10/38 and ablation of CFAE 15.8%, n=6/38). Acute procedural success was achieved in 87/88 patients (98.9%). Major complications included stroke (n=1/88, 1.1%), pericardial tamponade (n=1/88, 1.1%) and bradycardia with subsequent pacemaker implantation (n=3/88, 3.4%). No further major complications were documented. In 13/88 patients (14.8%) early arrhythmia-recurrence occurred (38.5%, n=5/13 after the index procedure and 61.5%, n=8/13 after re-ablation) during the 90-day blanking period.

Conclusions

Catheter ablation for atrial fibrillation in the very elderly shows favourable acute success and low complication rates. Long term success of catheter ablation and superiority to rate control in this patient population is unknown and requires investigation in the future.

Funding Acknowledgement

Type of funding sources: None.