Efficacy and safety in patients treated with a novel radiofrequency balloon: a two centres experience from the AURORA collaboration

Pulmonary vein isolation durability with fluoroscopy or 3D mapping-guided radiofrequency balloon ablation: a mandated remap study

Background

Effective balloon positionnking during pulmonary vein isolation (PVI) with a radiofrequency balloon (RFB) is crucial for optimal energy delivery, maximising lesion formation, and preventing gaps. Traditionally, fluoroscopy is used to guide pulmonary vein (PV) occlusion, however, this method exposes patients to radiation. Recently, RFBs equipped with 3D electroanatomical mapping (EAM) offer an alternative approach, potentially achieving the same results with reduced radiation exposure. Our main aim was to evaluate procedural characteristics, such as acute isolation and time-to-isolation (TTI), when the RFB is positioned based only on fluoroscopy feedback vs. fluoroscopy and a 3D-EAM. The secondary objective was to assess PVI durability through mandated remapping in asymptomatic patients from both groups.

Methods

A total of 60 patients were enrolled and underwent either a fluoroscopy-guided (FLUO, 30 patients) or fluoroscopy + 3D-EAM (3D-MAP, 30 patients) ablation. In each group, 15 patients without any documented recurrence underwent protocol-mandated repeat 3D-EAM six months after the index ablation. Procedural outcomes, lesion metrics, and safety profiles were assessed and compared between groups.

Results

At a median follow-up of 579 days, freedom from any atrial tachyarrhythmias (ATAs) was 89.7% in the FLUO group and 92.3% in the 3D-EAM group (P > 0.05). The latter was associated with significantly reduced fluoroscopy exposure (median 10.5 vs. 7.0 min, P < 0.005). Procedure time and efficacy metrics, including single-shot isolation rates and TTI, were comparable between groups. Durable PVI on a per PV basis was present in 54/60 (90%) vs. 57/60 (94%) of PVs in the FLUO and 3D-EAM groups, respectively (P = 0.9).

Conclusion

Radiofrequency balloon led to a high rate of durable PVI whether its guided by fluoroscopy only or 3D mapping. The latter allowed avoiding dye comsuption and a reduction of fluoroscopic times.

Radiofrequency balloon ablation: 1-year outcomes of the AURORA study

BACKGROUND

A novel irrigated radiofrequency balloon (RFB) for pulmonary vein isolation (PVI) integrated into a 3D mapping platform was recently launched.

METHODS

Patients undergoing a first atrial fibrillation (AF) ablation at two German high-volume EP centers were included into the prospective AURORA registry. All patients underwent clinical follow-up (FU) at 90, 180, and 360 days following ablation including 48-h Holter ECGs.

RESULTS

A total of 99 patients were enrolled (43/99 (43.4%) women, median age 67 years (interquartile range [IQR] 59-74), 43/99 (43.4%) persistent AF (Pers-AF), median left ventricular ejection fraction (LVEF) 60% (IQR 62-55)). Eighty-eight patients completed the follow-up. Acute PVI was achieved in 383/383 (100%) PV. Single-shot PVI was achieved in 211/383 (55.1%) PVs. Primary adverse events occurred in 3% of patients (1 postprocedural pharyngeal bleeding, 1 myocardial infarction, 1 non-cardiovascular death); no pericardial effusion, stroke, or phrenic nerve paralysis was observed. Median ablation and procedure times were 23 (IQR 18-32) and 67 (IQR 57-85) min, respectively. Median dose area product was 761 (IQR 509-1534) mGycm2. AF-free survival after a median FU of 361 (IQR 261-375) days was 78.4% for paroxysmal AF (PAF) and 75.4% for Pers-AF (p value = 0.828). Early recurrence of atrial tachyarrhythmia at the 90-day visit was the only independent predictor for AF recurrence at 1 year upon multiple regression analysis (hazard ratio [HR] 3.198; 95% confidence interval [95% CI] 1.036-10.32, p value = 0.0433).

CONCLUSION

RFB-based PVI is acutely successful, appears safe, and has comparable rhythm outcomes to other single-shot AF ablation tools. A recurrence of AF at 90 days predicts later AF recurrence.

Insights into the prospects of nanobiomaterials in the treatment of cardiac arrhythmia

Cardiac arrhythmia, a disorder of abnormal electrical activity of the heart that disturbs the rhythm of the heart, thereby affecting its normal function, is one of the leading causes of death from heart disease worldwide and causes millions of deaths each year. Currently, treatments for arrhythmia include drug therapy, radiofrequency ablation, cardiovascular implantable electronic devices (CIEDs), including pacemakers, defibrillators, and cardiac resynchronization therapy (CRT). However, these traditional treatments have several limitations, such as the side effects of medication, the risks of device implantation, and the complications of invasive surgery. Nanotechnology and nanomaterials provide safer, effective and crucial treatments to improve the quality of life of patients with cardiac arrhythmia. The large specific surface area, controlled physical and chemical properties, and good biocompatibility of nanobiomaterials make them promising for a wide range of applications, such as cardiovascular drug delivery, tissue engineering, and the diagnosis and therapeutic treatment of diseases. However, issues related to the genotoxicity, cytotoxicity and immunogenicity of nanomaterials remain and require careful consideration. In this review, we first provide a brief overview of cardiac electrophysiology, arrhythmia and current treatments for arrhythmia and discuss the potential applications of nanobiomaterials before focusing on the promising applications of nanobiomaterials in drug delivery and cardiac tissue repair. An in-depth study of the application of nanobiomaterials is expected to provide safer and more effective therapeutic options for patients with cardiac arrhythmia, thereby improving their quality of life.

Shortened radiofrequency delivery time to optimize efficiency and safety of pulmonary vein isolation with the radiofrequency balloon: insights from the COLLABORATE registry

AIMS

Previous clinical studies on pulmonary vein isolation (PVI) with a radiofrequency balloon (RFB) reported safe and effective procedures using conventional ablation settings with 20/60 s RF delivery via posterior/anterior (PST/ANT) electrodes. The latest evidence suggests that reducing the application time to 15 s (s) on the posterior wall when facing the oesophageal region is as effective as applying 20 s. To prospectively assess whether reducing RF time on PST/ANT segments to 15/45 s can ensure sufficient quality of lesion metrics and compare the new shortened ablation settings with the conventional one in terms of safety, and effectiveness at 1-year.

METHODS AND RESULTS

A total of 641 patients from seven European centres were enrolled in a collaborative registry, with 374 in the conventional RF delivery group and 267 in the shortened RF delivery group. Procedural outcomes, lesion metrics, and safety profiles were assessed and compared between the groups. Freedom of any atrial tachycarrythmias at one year was 85.4% and 88.2% in the SHRT and CONV groups, respectively. The shortened RF delivery strategy was associated with significantly shorter procedure times (median 63.5 vs. 96.5 min, P < 0.001) and shortened fluoroscopy exposure (median 10.0 vs. 14.0 min, P < 0.001) compared to conventional delivery. Efficacy metrics, including first-pass isolation rates and time to isolation, were comparable between groups. Shortened RF delivery was associated with a lower incidence of procedural complications (1.4% vs. 5.3%, P = 0.04) and optimized thermal characteristics.

CONCLUSION

Analyses from the COLLABORATE registry demonstrate that shortening RF energy delivery times to 15/45 s (PST/ANT) during PVI with the RFB resulted in comparable freedom from recurrent atrial tachyarrhythmia compared to conventional delivery times with comparable efficiency and safety.

State-of-the-art pulsed field ablation for cardiac arrhythmias: ongoing evolution and future perspective

Pulsed field ablation (PFA) is an innovative approach in the field of cardiac electrophysiology aimed at treating cardiac arrhythmias. Unlike traditional catheter ablation energies, which use radiofrequency or cryothermal energy to create lesions in the heart, PFA utilizes pulsed electric fields to induce irreversible electroporation, leading to targeted tissue destruction. This state-of-the-art review summarizes biophysical principles and clinical applications of PFA, highlighting its potential advantages over conventional ablation methods. Clinical data of contemporary PFA devices are discussed, which combine predictable procedural outcomes and a reduced risk of thermal collateral damage. Overall, these technological developments have propelled the rapid evolution of contemporary PFA catheters, with future advancements potentially impacting patient care.

High efficiency single-catheter workflow for radiofrequency atrial fibrillation ablation in the QDOT catheter era

BACKGROUND

High-power short-duration (HPSD) ablation may improve the consistency and efficiency of pulmonary vein isolation (PVI). The novel QDOT Micro™ catheter (Biosense Webster, Inc.) with temperature feedback and microelectrodes aims to enhance PVI efficiency and safety. This study wants to evaluate the feasibility, safety, and efficiency of a standardized single-catheter workflow for PVI using QDOT (Q-FLOW).

METHODS

The Q-FLOW includes single transeptal access, radiofrequency encircling of the PVs using a power of 50 W in a temperature/flow-controlled mode, and validation of the circles with microelectrodes. A 1:1 propensity-matched cohort of patients treated with conventional power-controlled ablation using a circular mapping catheter (CMC-FLOW) was used to compare procedural and clinical outcomes.

RESULTS

A total of 150 consecutive atrial fibrillation patients (paroxysmal 67%, persistent 33%) were included. First-pass isolation rate was 86%. Procedural time, X-ray time, and dose were significantly lower for the Q-FLOW vs the CMC-FLOW (67.2 ± 17.9 vs 88.3 ± 19.2 min, P < 0.001; 3.0 ± 1.9 vs 5.0 ± 2.4 min, P < 0.001; 4.3 ± 1.9 vs 6.4 ± 2.3 Gycm2, P < 0.001). Complications were numerically but not significantly lower in the Q-FLOW group (2 [1.3%] vs 7 [4.7%], P = 0.091). There was no difference in arrhythmia recurrence at 12 months (atrial arrhythmia-free survival rate, 87.5% vs 84.4%, P = 0.565).

CONCLUSION

A streamlined single-catheter workflow for PVI using QDOT was feasible and safe, resulting in a high rate of first-pass isolation and a low complication rate. The Q-FLOW further improved the efficiency of PVI compared to the standard CMC-FLOW, without difference in the 12-month outcome.

Very high-power short-duration catheter ablation for treatment of cardiac arrhythmias: Insights from the FAST and FURIOUS study series

The QDOT MICRO™ Catheter is a novel open-irrigated contact force-sensing radiofrequency ablation catheter. It offers very high-power short-duration (vHPSD) ablation with 90 W for 4 s to improve safety and efficacy of catheter ablation procedures. Although the QDOT MICRO™ Catheter was mainly designed for pulmonary vein isolation (PVI) its versatility to treat atrial fibrillation (AF) and other types of arrhythmias was recently evaluated by the FAST and FURIOUS study series and other studies and will be presented in this article. Available study and registry data as well as case reports concerning utilization of the QDOT MICRO™ Catheter for the treatment of cardiac arrhythmias including AF, focal and macroreentry atrial tachycardia, typical atrial flutter by cavotricuspid isthmus block, premature ventricular contractions, and accessory pathways were reviewed and summarized. In summary, the QDOT MICRO™ Catheter showed safety and efficacy for PVI and is able to treat also other types of arrhythmias as is was recently evaluated by case reports and the FAST and FURIOUS studies.

Comparison between a Novel Radiofrequency-Balloon and a Standard Cryo-Balloon in Pulmonary Vein Isolation: A Propensity-Score-Matched Analysis

Background/Objectives: Single-shot devices are important tools for efficient pulmonary vein isolation (PVI) in atrial fibrillation (AF). In addition to the standard cryo-balloon (CB) catheter, a novel multi-electrode radiofrequency balloon-catheter (RFB, Heliostar, Biosense Webster, Irvine, CA, USA) with 3D-mapping-integration is available. Currently, there is no evidence allowing for a direct comparison between RFB-PVI and CB-PVI in a matched population. The study aimed to assess the procedural data, safety profiles, and outcomes of RFB-PVI versus CB-PVI. Methods: In this prospective registry study, symptomatic AF patients undergoing first-time PVI from January 2019 to April 2023, using RFB or CB, were included, with patients matched in a 1:2 ratio to reduce potential confounders. Results: The results from 171 consecutive RFB patients and 342 matched CB patients showed comparable recurrence-free survival after 12 months (81.3% RFB vs. 76.8% CB, p = 0.359). The RFB group had a longer procedure duration (88 vs. 73 min, p < 0.001) and longer fluoroscopy time (18.9 vs. 14.5 min, p < 0.001). Conclusions: In conclusion, the novel RFB system enables efficient and safe PVI, which is broadly comparable to the established CB system. However, the 3D-mapping integration in RFB did not reduce fluoroscopy time compared to CB.

Atrial Fibrillation Ablation with a Novel Fully 3D-Mapping-Integrated Multi-Electrode Radiofrequency Balloon Catheter

Pulmonary vein isolation (PVI), as the cornerstone of atrial fibrillation (AF) ablation, has emerged a widely used therapy for patients suffering from AF. To improve PVI efficiency, single-shot catheters (SSCs) have been developed. Regrettably, SSCs are not integrated into 3D-mapping technology. In that regard, a novel radiofrequency balloon catheter (RFBC, Heliostar, Biosense Webster) with full integration into 3D-mapping technology has been developed. The aim of this study was to assess operative and follow-up outcomes of the RFBC in AF patients. In this monocentric prospective registry, patients with a first-time PVI using the RFBC were included. Follow-up visits were scheduled 3, 6, 12 and 24 months after ablation and in case of symptoms. A total of 171 patients (36.8% female) were included, with a mean age of 68.5 ± 10.2 years. Among them, 63 patients (36.8%) presented with persistent AF. Notably, no major periprocedural complications were observed. The mean follow-up period was 287 ± 157 days. In the Kaplan-Meier analysis, the estimated recurrence-free survival after 12 months was 81.8%. Based on our data, PVI with the fully 3D-mapping-integrated RFBC seems to be safe and effective and to have a favorable 12-month outcome in patients with paroxysmal and persistent AF.

Implementation of the multielectrode radiofrequency-balloon in real-world clinical practice-operator learning curve and procedural outcome at a high-volume center

Background

The novel multielectrode radiofrequency (RF) balloon catheter (HELIOSTAR™, Biosense Webster) is a new technology for pulmonary vein isolation (PVI) in atrial fibrillation (AF), combining RF-ablation and 3D-mapping visualization with the concept of a "single-shot"-ablation device. This study evaluates the operator learning curve und procedural outcome during implementation of the multielectrode RF-balloon at a high-volume center.

Methods

The first 40 patients undergoing PVI by multielectrode RF-balloon catheter at Heidelberg University Hospital were included in this prospective study. Procedural outcome was analyzed over the course of increasing experience with the device.

Results

157/157 pulmonary veins (PVs) were successfully isolated with the RF-balloon catheter, in 73.2% by a single RF-application. Median time to isolation (TTI) was 11.0 s (Q1 = 8.0 s; Q3 = 13.8 s). Median procedure time was 62.5 min (Q1 = 50.0 min; Q3 = 70.5 min). LA-dwell time was 28.5 min (Q1 = 23.3 min; Q3 = 36.5 min). Median fluoroscopy duration was 11.6 min (Q1 = 10.1 min; Q3 = 13.7 min). No serious procedure-related complications were observed, apart from one case of unclear, post-procedural acute-on-chronic kidney injury. With increasing operator experience, an additional reduction in procedure duration was observed.

Conclusion

Rapid implementation of a "single shot"-ablation device combining RF-ablation and 3D-mapping can be achieved with high acute procedural efficacy and safety at a high-volume center. Previous experience with "single-shot" ablation devices may be advantageous for time-efficient introduction of the novel RF-balloon catheter into clinical practice.

Clinical Trial Registration

ClinicalTrials.gov; Identifier NCT0560361.

Safety of the Radiofrequency Balloon for Pulmonary Vein Isolation: A Focus on Lesion Metric Analysis of Posterior Electrodes

Previous clinical studies on pulmonary vein isolation (PVI) with radiofrequency balloons (RFB) reported safe and effective procedures for a 20 s RF delivery via posterior electrodes. Recent recommendations from the manufacturer suggest reducing the application time to 15 s on the posterior wall (PW) when facing the esophagus region. Here, we retrospectively assess whether 15 s of RF delivery time on posterior electrodes is safe while still ensuring lesion metrics of sufficient quality. This retrospective study included 133 patients with paroxysmal and persistent atrial fibrillation who underwent PVI using an RFB (Heliostar, Biosense Webster, Inc., Irvine, CA, USA) at two European centers. The ablation protocol was set for an RF duration of 20 s/60 s for the posterior/anterior electrodes. A multielectrode temperature probe was systematically used. In the case of an esophageal temperature rise (ETR) above 42 °C (ETR+), an endoscopic evaluation was performed. All posterior electrode lesion metric dynamics (temperature (T) and impedance (Z)) were collected from the RFB generator and analyzed offline. In total, 2435 posterior electrode applications were analyzed. With an RF delivery of 19.8 (19.7-19.8) s, the median impedance drop was 18.4 (12.2-25.2) Ω, while the temperature rise was 11.1 (7.1-14.9) °C. Accordingly, impedance (84.6 (79.3-90.2) Ω) and temperature plateaus (38 (35.3-41.1) °C) were reached at 13.9 (10.6-16) s and 16.4 (12.6-18.5) s, respectively. Overall, 99.6% and 95.8% of electrodes reached 90% (16.6 Ω) and 95% (17.5 Ω) of their impedance drops within 15 s of RF delivery, while 97.2% and 92.8% achieved 90% (34.2 °C) and 95% (36.1 °C) of their temperature rise to reach the plateaus within 15 s of RF delivery. An ETR >42 °C occurred in 37 (30.1%) patients after 17.7 ± 2.3 s of RF delivery. In the ETR+ group, the impedance drop and temperature rise on the posterior electrodes were higher compared to patients where ETR was <42 °C. Two asymptomatic thermal esophageal injuries were observed. In conclusion, 15 s of RF delivery on the posterior electrodes provides a good balance between safety, with no esophageal temperature rise, and efficacy with high-profile lesion metrics.

Outcomes of pulmonary vein isolation with radiofrequency balloon vs. cryoballoon ablation: a multi-centric study

AIMS

Cryoballoon (CB) ablation is the mainstay of single-shot pulmonary vein isolation (PVI). A radiofrequency balloon (RFB) catheter has recently emerged as an alternative. However, these two technologies have not been compared. This study aims to evaluate the freedom from atrial tachyarrhythmias (ATas) at 1 year: procedural characteristics, efficacy, and safety of the novel RFB compared with CB for PVI in patients with paroxysmal atrial fibrillation (AF).

METHODS AND RESULTS

This prospective multi-centre study included consecutive patients with symptomatic drug-resistant paroxysmal AF who underwent PVI with RFB or CB between July 2021 and January 2022 from three European centres. A total of 375 consecutive patients were included, 125 in the RFB group and 250 in the CB. Both groups had comparable clinical characteristics. At 12.33 ± 4.91 months, ATas-free rates were 83.20% and 82.00% in the RFB and CB groups, respectively (P > 0.05). Compared with the CB group, the RFB group showed a shorter procedure time [59.91 (45.80-77.12) vs. 77.0 (35.13-122.71) min (P < 0.001)], dwell time [19.59 (14.41-30.24) vs. 27.03 (17.11-57.21) min (P = 0.04)], time to isolation, and thermal energy delivery in all pulmonary veins (P < 0.001). First-pass isolation was comparable. No major complications occurred in either group, with no stroke, atrio-oesophageal fistula, or permanent phrenic nerve injury. Transient phrenic nerve palsy occurred more frequently with CB than RFB (7.20% vs. 3.20%; P = 0.02). Oesophageal temperature rise occurred in 21 (16.8%) patients in the RFB group, and gastroscopy showed erythema in two of them with complete recovery after 30 days.

CONCLUSIONS

The RFB appears to have a safety and efficacy profile similar to that of the CB for PVI. Shorter procedural times appear to be driven by shorter left atrial dwell and thermal delivery times.