Results of ICE-Guided Isolation of the Superior Vena Cava With Pulsed Field Ablation

Ensuring catheter-tissue contact with intra-cardiac echocardiography during pulsed-field ablation improves procedure outcome in patients with atrial fibrillation

BACKGROUND

Catheter-tissue contact is critical in creating durable lesions during pulsed-field ablation (PFA) of atrial fibrillation (AF).

OBJECTIVE

We aimed to compare the reconnection rate of previously ablated targets utilizing PFA with vs without intracardiac echocardiography (ICE)-guidance for confirmation of tissue contact.

METHODS

This multicenter prospective study included consecutive paroxysmal and persistent AF patients undergoing their first procedure using the PFA system. Patients were classified as ICE-group if ICE was used for assessment of catheter-tissue-contact (n=310) or Fluoro-group: fluoroscopy-guided ablation (n=286). All patients received isolation of PVs (PVI); left atrial posterior wall (LAPW) was done in most at the index procedure. Further ablations were performed only in the presence of spontaneous triggers or documentation that those triggers were responsible for arrhythmia either spontaneously or after isoproterenol challenge.

RESULTS

Baseline characteristics were comparable between the groups. At the end of the follow-up, arrhythmia recurrence was noted in 39 (12.6%) and 64 (22.3%) patients in the ICE and fluoro-group respectively (p=0.002). All 39 patients in the ICE-group and 54 (84%) patients in the fluoro-group received repeat ablation. At the redo procedure, reconnection of previously ablated structures was detected in 4/39 (10.3%) and 32/54 (59.2%) patients in the ICE and fluoro-group respectively (p<0.001). 'Fluoroscopy-guided' ablation was found to be an independent predictor of reconnection (OR = 8.548 95% CI 3.224 - 22.667; p- value = <0.001) as well as recurrence (OR: 1.221, 95% CI 1.001 - 1.971, p=0.021).

CONCLUSION

ICE-guided PFA with confirmed catheter-tissue contact was associated with better success rate and significantly lower reconnection rate in AF patients.

Nonlinear Relationship Between Left Atrial Volume Measured by Computed Tomography and Recurrent Atrial Arrhythmias in Patients Undergoing Catheter Ablation for Atrial Fibrillation

BACKGROUND

Left atrial remodeling is commonly believed to contribute to the recurrence of atrial arrhythmias following catheter ablation for atrial fibrillation (AF). However, the relationship between left atrial volume (LAV) assessed via left atrial computed tomography (LACT) and AF recurrence remains insufficiently explored.

AIM

This study aimed to examine the association between LAV measured by LACT and the recurrence of AF.

METHODS

In this cohort study, 532 consecutive AF patients undergoing their first catheter ablation at Fuwai Hospital were enrolled. The primary outcome was the recurrence of atrial arrhythmias after a 90-day blanking period following the ablation procedure. Semi-automated software (Materialize Mimics) was utilized to analyze LACT data and estimate left atrial size.

RESULTS

After a median follow-up duration of 16.7 months, 189 patients experienced AF recurrence. Multivariate Cox regression revealed a significant positive association between LAV and recurrence risk (hazard ratio, 1.36; 95% confidence interval, 1.11-1.66, p = 0.003). Restrictive cubic spline analysis uncovered a U-shaped nonlinear association between LAV and AF recurrence, with an inflection point identified at 99.3 mL (P for nonlinear < 0.001, P for overall < 0.001). Kaplan-Meier survival analysis demonstrated significantly lower freedom from atrial arrhythmias in the 1st and 4th quartile compared to the 2nd quartile (Log-rank, p < 0.001).

CONCLUSION

In AF patients undergoing initial catheter ablation, LAV was found to have a positive relationship with the risk of recurrent atrial arrhythmias, exhibiting a U-shaped nonlinear pattern. Both excessively high and low LAV levels were associated with an elevated risk of AF recurrence.

Intracardiac Echo Versus Fluoroscopic Guidance for Pulsed Field Ablation: Single-Center Real-Life Study

Background: Pulsed field ablation (PFA) is a novel non-thermal modality for catheter ablation (CA) in atrial fibrillation (AF) and has been replacing traditional thermal modalities. There have been studies in the past comparing fluoroscopic (FL) versus intracardiac echocardiogram (ICE) guidance for thermal ablation modalities. However, there have not been studies that compare outcomes for PFA performed under ICE versus FL guidance. Methods: This study was designed in a longitudinal cross-sectional format. A total of 196 patients who underwent PFA for AF at Prisma Health Richland were selected for the retrospective analysis. Patients were divided into two groups: those who underwent PFA under FL guidance (103 patients) versus ICE guidance (93 patients). The recurrence of atrial arrhythmias in the six-month follow-up period was studied. Multivariate regression analysis was performed to assess the difference in the association of either modality with recurrence of atrial arrhythmias. Bayesian non-inferiority models were used to analyze the non-inferiority between the modalities. Results: A total of 31 patients (30.1%) in the fluoro group had documented atrial arrhythmias in the six months following ablation. While 23 patients (24.7%) in the ICE group had documented atrial arrhythmias in the six-month follow-up period. The recurrence of AF was noted in 22.3% (22 patients) in the fluoro group and 14% (13 patients) in the ICE group. After running the multivariate regression analysis models, PFA under fluoroscopic guidance did not differ from ICE guidance, in terms of the recurrent atrial arrhythmias in the six-month follow-up (Adjusted Odds Ratio: 0.964; 95% CI: 0.336-2.772). The fluoro and ICE groups also did not differ in terms of six-month atrial fibrillation recurrence (Adjusted Odds Ratio: 2.43; 95% CI: 0.649-9.19). Non-inferiority analysis with Bayesian model was carried out, comparing the fluoro group and the ICE group in terms of freedom from arrhythmias in the six-month follow-up, and no inferiority was proved (95% confidence interval: -0.18-0.053), with a 61.03% chance of ICE-guided PFA being superior to fluoro guidance in terms of recurrence free interval, but statistical significance was not reached. Conclusions: Mean fluoroscopic time in the FL guidance group was 15.9 min, while no radiation exposure was documented in the ICE group. CA performed under FL versus ICE guidance did not differ statistically in terms of six-month recurrence of atrial arrhythmias in general and AF in particular.

The Growing Role of Intracardiac Echo in Congenital Heart Disease Interventions

Advancements in congenital heart disease (CHD) care have significantly improved survival, leading to a growing population of adults with congenital heart disease (ACHDs). Many of these patients require ongoing interventions for residual defects, conduit or valve dysfunction, and arrhythmia management, often performed using transcatheter techniques. Imaging plays a critical role in ensuring procedural success and safety. Intracardiac echocardiography (ICE) has emerged as an essential imaging modality in ACHD interventions. With continuous technological advancements, ICE offers several advantages over transesophageal echocardiography (TEE) and transthoracic echocardiography (TTE), including superior visualization, real-time guidance, and the ability to avoid general anesthesia. These benefits have made ICE the preferred imaging tool for many transcatheter procedures. This review explores the expanding role of ICE in ACHD interventions, highlighting its applications in structural and electrophysiological procedures. By enhancing procedural precision and reducing complications, ICE is transforming the management of ACHD patients, optimizing outcomes, and improving long-term care for this complex and growing population.

Left Atrial Substrate Modification for Long-Standing Persistent Atrial Fibrillation and Left Atrial Macro- or Micro-Reentrant Tachycardia Using a Single-Shot Pulsed Field Ablation System-A Case Series

Background: Pulsed field ablation [PFA] is a novel ablation technique for pulmonary vein isolation [PVI] in patients with paroxysmal and persistent atrial fibrillation. However, data for the efficacy and safety of PFA for left atrial substrate modification using a single shot PFA system, in patients with long-standing persistent atrial fibrillation [AF] and left atrial macro- as well as micro-reentrant atrial tachycardia [LAMRT], are scarce. Here, we provide a small, single-center case series regarding the efficacy and safety of left atrial substrate modification using a single-shot PFA system. Methods: Nine patients with long-standing persistent AF and LAMRT underwent redo-PVI and left atrial substrate modification using a single-shot PFA system. Patients were subsequently followed up for 1 year. Results: The median age was 64 years [IQR 55.5-75], with 44% of the participants being female. The median time since the first diagnosis of AF was 7 years [IQR 4-15.5]. After re-PVI, posterior wall isolation was performed in five patients, roof isolation in six patients, and anterior wall ablation between the superior mitral annulus and the right superior pulmonary vein [RSPV] in five patients. In two patients, cavotricuspid isthmus ablation was additionally performed to treat typical atrial flutter. The acute procedural success rate was 100%, with all LAMRTs and typical flutters successfully terminating by ablation. At 1-year follow-up, four patients [44%] experienced a recurrence of any atrial arrhythmia. Median time to recurrence was 164 days [138-212.8]. Importantly, no acute or chronic complications were observed. Conclusions: In this small, single-center case series, left atrial substrate modification for long-standing persistent AF and AT using a single-shot PFA system was safe and showed an excellent acute success rate.