HotBalloon Pulmonary Vein Isolation Registry Study　- Real-World Efficacy and Safety of HotBalloon Ablation.

BACKGROUND: Radiofrequency hotballoon (RHB) is an ablation device used for atrial fibrillation (AF) treatment. The efficacy and safety of RHB-based pulmonary vein isolation (PVI) in real-world practice are unknown.Methods and Results: A multicenter, prospective registry study (UMIN000029567) enrolled AF patients who underwent RHB-PVI. The primary endpoint was the AF recurrence-free survival rate at 12 months after PVI. Of the 679 patients enrolled, 613 (90.3%; paroxysmal AF, n=370; persistent AF, n=136; long-standing AF, n=107) underwent initial RHB-PVI. Acute isolation using only the RHB was successful for 55.6% of patients and 83.5% of pulmonary veins (PVs). The acute isolation rate was higher for patients with paroxysmal AF and more experienced centers. Antiarrhythmic drugs were prescribed after 3 months for 47.5% of patients. The AF recurrence-free survival rate at 12 months was 83.7%. Procedure-related complications including atrio-esophageal fistula (n=1) and phrenic nerve injury (persistent; n=4, permanent; n=2) were observed in 19 (3.1%) patients. Five (1.7%) of the 302 patients who underwent pre-procedural and post-procedural multidetector computed tomography had severe PV stenosis. CONCLUSIONS: The size-adjustable RHB has been used for the treatment of various AF types. The arrhythmia recurrence-free rate at 12 months, with the use of antiarrhythmic drugs in approximately half of the patients, was acceptable, but the acute isolation rate using the RHB requires further improvement.

Development of a new HotBalloonTM ablation catheter equipped with a balloon surface temperature monitoring sensor for pulmonary vein isolation.

The balloon surface temperature (BST) should be monitored to ensure the success of the ablation procedure using the HotBalloonTM ablation catheter (HBC) in clinical settings. Therefore, we sought to develop a new HBC equipped with a surface temperature monitoring sensor. The BST was evaluated using a pseudo-tissue model and a thermocouple to imitate catheter insertion into the pulmonary vein. Thermo-fluid analysis with computer-aided engineering (CAE) was performed to analyse the temperature distribution in the catheter and the balloon. The CAE analysis reproduced the results from a pseudo-tissue model experiment and demonstrated that some fluid zones inside the catheter shaft had a nearly identical temperature as the BST during the liquid suction period. The pseudo-tissue model experiment confirmed that the temperature was almost the same between the balloon surface and the position of 5 mm inside the catheter shaft from the proximal end of the balloon. A thermocouple placed at 5 mm or 25 mm from the proximal end of the balloon within the catheter shaft showed an equivalent temperature result. This 5-25-mm distance is acceptable to set the BST monitoring sensor inside the catheter shaft, since the sensor can help accurately estimate the BST.

Iatrogenic atrial septal defect after HotBalloon ablation of atrial fibrillation.

HotBalloon-based pulmonary vein isolation (HBPVI) has yielded encouraging clinical results in the treatment of atrial fibrillation (AF). Balloon ablation requires a larger sheath, which raises the concern for a persistent iatrogenic atrial septal defect (iASD). The present study aimed to investigate the incidence, clinical features, and the predictive factors of transthoracic echocardiography (TTE)-detectable iASD after HBPVI. All patients who underwent HBPVI of AF with pre- and post-ablation TTE were retrospectively analyzed. A 17-French steerable deflectable guiding sheath was inserted into the left atrium (LA) after a transseptal puncture, and an 8-French sheath was inserted via a single transseptal hole. In a total of 190 patients, 98 (52%) paroxysmal AF (PAF) and 92 (48%) non-PAF, the iASD was detected in 18 (9.4%) with a mean follow-up period of 12.7 ± 2.5 months after HBPVI. All patients had no clinical symptoms related to iASD. No embolic or heart failure events occurred. In the multivariate analysis, LA volume index and LA procedure time were identified as significant independent predictors of iASD. After HBPVI, TTE-detectable iASD was found in 9.4% of study patients. Larger LA size and longer LA procedure time were predictive factors for the persistence of iASD. All patients with iASD had no clinical symptoms 12 months after HBPVI; however, long-term follow-up may be necessary.

Transition of chemical management in Japan -Shift to self-regulation and measures for small businesses.

Increased variety and use of chemicals and the number of chemical disasters have changed chemical management. Europe and the United States have adopted self-regulation in chemical management; furthermore, countries worldwide must comply with the relevant United Nations recommendations and international standards for chemical management. Japan has experienced numerous pollution incidents and occupational disasters, resulting in the development of laws and regulations on chemical management; however, these policies are inconsistent with international trends. In particular, the shift from a compliance approach to self-regulation and measures for small businesses remain as challenges. This paper discusses the current situation and issues in chemical management in Japan, focusing on international trends.

Pulmonary vein stenosis after HotBalloon pulmonary vein isolation of paroxysmal atrial fibrillation.

HotBalloon-based pulmonary vein isolation (HBPVI) has yielded encouraging clinical results in the treatment of paroxysmal atrial fibrillation (PAF). However, pulmonary vein (PV) stenosis remains a concern. The influence of longer application duration on PV stenosis has not yet been systematically evaluated. All patients who underwent first HBPVI of PAF with pre- and post-ablation computed tomography (CT) were included. We used single-shot technique with application duration of 180 s in the RSPV, 180-240 s in the LSPV, and 120 s in the lower PV procedures. PV stenosis was analyzed using CT and categorized as moderate (50-70%), and severe (> 70%) reduction in PV diameter. We analyzed imaging of the PV anatomy before ablation and during follow-up in 84 patients. Among them, 7 (8.3%) showed moderate stenosis, and 3 (3.6%) had severe stenosis including one total occlusion patient. All severe stenosis and total occlusion occurred in RSPV and LSPV procedures with longer application duration. No severe stenosis nor total PV occlusion occurred in inferior PV procedures with shorter application duration. The incidence of PV stenosis ≥ 50% or total PV occlusion was significantly lower in inferior PV than RSPV and LSPV procedures (0.6%, 6.0%, 8.0%, p = 0.01, respectively). All cases of PV stenosis including total PV occlusion patients were asymptomatic. No intervention for PV stenosis was performed. The risk of PV stenosis in HBPVI was rare in lower PV procedure with shorter application duration. An application duration setting of 120 s in lower PV procedure might be effective to prevent PV stenosis.

Efficacy and Safety of SATAKE HotBalloon® Catheter for Treatment of Paroxysmal Atrial Fibrillation　- A Post-Marketing Surveillance Study.

BACKGROUND: SATAKE HotBalloon®catheter (HBC) is a radiofrequency balloon catheter for the treatment of atrial fibrillation (AF), and was approved for use in Japan to treat drug-resistant paroxysmal AF in 2015. Post-marketing surveillance study was conducted by Toray Industries, Inc. to evaluate the efficacy and safety of HBC treatment in patients with paroxysmal AF in a real-world setting. This study is the first nation-wide survey of HBC treatment for paroxysmal AF in clinical practice in Japan.Methods and Results:This was a single-arm, multicenter observational study with an observation period of 48 weeks after ablation. Pulmonary vein isolation and AF non-recurrence rates were evaluated and adverse events (AEs) were observed at 46 sites in Japan. An AF event was defined as recurrence of AF or re-ablation from 12 to 48 weeks after ablation. The success rate of pulmonary vein isolation was 99.0% (486/491) for patients with AF. The cumulative AF non-recurrence rate was 94.1% at 24 weeks and 87.8% at 48 weeks. AEs were found to occur 21.5% (114/530), and ablation-related AEs were found to occur 2.6% (14/530) during the study period, with the most common being pericardial effusion (0.8%, 4/530). CONCLUSIONS: This study demonstrates the efficacy and safety of HBC ablation in Japanese patients with recurrent symptomatic paroxysmal AF refractory to antiarrhythmic therapy.

Acute efficacy and clinical outcomes using HotBalloon for pulmonary vein isolation in patients with a left common pulmonary vein.

INTRODUCTION: HotBalloon material is compliant and the balloon size can be enlarged by increasing the intraballoon injection volume. HotBalloon-based pulmonary vein isolation (PVI) has demonstrated encouraging clinical results in the treatment of paroxysmal atrial fibrillation (PAF), however, the acute efficacy and clinical outcomes of the HotBalloon-based PVI have never been fully investigated in patients with a left common pulmonary vein (LCPV). METHODS AND RESULTS: One hundred fifty-three PAF patients underwent HotBalloon-based PVI. Three-dimensional computed tomography was performed in all patients before the ablation. An LCPV was observed in 40 (26%) patients. For HotBalloon ablation of an LCPV, in patients with an LCPV of superoinferior diameter <34 mm, the left common ostium was preferably isolated if sufficient occlusion could be achieved. In patients with an LCPV diameter ≥34 mm, left superior and inferior branches of the LCPV were targeted individually. The number of HotBalloon applications in patients with LCPV was significantly smaller than without LCPV (7.3 ± 2.0 vs 8.1 ± 2.1; P = .04). In patients with LCPV diameter <34 mm, 75% of LCPVs successfully achieved full balloon occlusion (50% were isolated by application at the LCPV ostium alone, 25% by application at the LCPV ostium followed by either superior or inferior LCPV branch ablation) and 25% were isolated individually. One year after a single session, the arrhythmia-free rates were similar between patients with and without LCPV (77% vs 74%, log rank, P = .86). CONCLUSIONS: HotBalloon-based PVI delivers long-term favorable success rates with fewer HotBalloon applications in paroxysmal AF patients with an LCPV.

Insights into guidewire related complication during HotBalloon ablation in patients with atrial fibrillation: What should we know?

A 78-year-old woman with drug-resistant persistent atrial fibrillation was referred for catheter ablation by HotBalloon. All pulmonary veins were successfully ablated by the HotBalloon. During the additional roof ablation by the HotBalloon, sudden hemoptysis developed. It was observed that a guidewire advanced far distal to the left superior pulmonary vein (LSPV) branch. The pulmonary vein angiography demonstrated LSPV branch injury. After activated clotting time control, the hemoptysis disappeared spontaneously. The patient was discharged 6 days after the procedure without any sequela.

HotBalloon Ablation of the Pulmonary Veins for Paroxysmal AF: A Multicenter Randomized Trial in Japan.

BACKGROUND: Point-by-point catheter ablation is an established treatment for drug-refractory paroxysmal atrial fibrillation (PAF). However, it is time consuming, requires excellent technique to achieve complete pulmonary vein (PV) isolation, and is associated with severe complications. OBJECTIVES: The purpose of this study was to evaluate the safety and effectiveness of a HotBalloon ablation (HBA) compared with antiarrhythmic drug therapy (ADT) for the treatment of PAF. METHODS: A prospective multicenter randomized controlled study was conducted in Japan. Patients with symptomatic PAF refractory to antiarrhythmic drugs (Class I to IV) were randomized to HBA or ADT at a 2:1 ratio and assessed for effectiveness in a comparable 9-month follow-up period. RESULTS: A total of 100 patients in the HBA group and 43 patients in the ADT group received treatment at 17 sites. HBA procedure produced acute complete PV isolation in 98.0% (392 of 400) of the PVs and in 93.0% (93 of 100) of patients in the HBA group. The chronic success rates after the 9-month effective evaluation period were 59.0% in the HBA group (n = 100) and 4.7% in the ADT group (n = 43; p < 0.001). The incidence of major complications was 11.2% (15 of 134 patients). The incidences of PV stenosis (>70%) and transient phrenic nerve injury were 5.2% and 3.7%, respectively. The mean fluoroscopy time was 49.4 ± 26.6 min (n = 134), and the mean procedure duration was 113.9 ± 31.9 min (n = 133). CONCLUSIONS: This study demonstrates the superiority of HBA compared with ADT for treatment of patients with PAF, and a favorable safety profile.

The feasibility of a Box isolation strategy for non-paroxysmal atrial fibrillation in elderly patients.

BACKGROUND: Catheter ablation of non-paroxysmal atrial fibrillation (non-PAF) is a therapeutic challenge especially in elderly patients. This study describes the feasibility of a posterior left atrium isolation as a substrate modification in addition to pulmonary vein isolation, the so-called Box isolation, for elderly patients with non-PAF. METHODS: Two hundred twenty-nine consecutive patients who underwent Box isolations for drug-refractory non-PAF were divided into two groups according to their age; younger group comprising 175 patients aged <75 years and elderly group comprising 54 patients aged ≥75 years. RESULTS: During 23.7±12.0 months of follow-up, the arrhythmia-free rates after one procedure were 53.1% in younger group versus 48.1% in elderly group (p=0.50). Following the second procedure, all patients had electrical conduction recoveries along the initial Box lesion. However, a complete Box re-isolation was highly established in both age groups (87.1% vs. 92.9%, respectively; p=1.00). Recurrence of macro-reentrant atrial tachycardia was mainly associated with the gaps through the initial Box lesion in both age groups (25.8% vs. 21.4%, p=1.00), but typical cavo-tricuspid isthmus (CTI) dependent atrial flutter was significantly observed in the elderly patients' group only (all events were observed within 6 months after the initial procedure; 3.2% vs. 28.6%, p=0.009). After two procedures, the arrhythmia-free rates increased to 73.1% in younger group versus 66.7% in elderly group (p=0.38). The occurrence rate of procedural-related complications did not differ between the two age groups, and there were no life-threatening complications even in elderly patients. CONCLUSIONS: Box isolation of non-PAF is effective and safe even in elderly patients. A prophylactic CTI ablation combined with Box isolation might be feasible to improve the long-term outcome.

Is It Necessary to Achieve a Complete Box Isolation in the Case of Frequent Esophageal Temperature Rises? Feasibility of Shifting to a Partial Box Isolation Strategy for Patients With Non-Paroxysmal Atrial Fibrillation.

INTRODUCTION: There are some cases with frequent luminal esophageal temperature (LET) rises despite titrating the radiofrequency energy while creating a linear lesion for the Box isolation of atrial fibrillation (AF). Little is known about the feasibility of redesigning the ablation lines for a modified Box isolation strategy to prevent fatal esophageal injury in those cases. METHODS AND RESULTS: Two hundred and seventeen patients who underwent a Box isolation of non-paroxysmal AF were evaluated. We divided them into 2 groups, patients in whom a box lesion set of the entire posterior left atrium had been achieved (complete Box isolation [CBI]; n = 157) and those in whom 2 additional peri-esophageal vertical lines were created at both the right and left ends of the esophagus, and those areas were left with an incomplete isolation when frequent rapid LET rises above 39.0 °C were observed while creating the floor line (partial Box isolation [PBI]; n = 60). During 20.1 ± 13.9 months of follow-up, the arrhythmia-free rates were 54.1% in the CBI group versus 48.3% in the PBI group (P = 0.62). In the second session, a complete Box isolation was highly achieved even in the PBI group (94.3% vs. 83.3%, respectively; P = 0.17) and after 2 procedures, the arrhythmia-free rates increased to 75.2% vs. 68.3%, respectively (P = 0.34). There was no symptomatic esophageal injury in the PBI group. CONCLUSION: In the case of frequent LET rises while creating the linear lesions for the Box isolation strategy for non-paroxysmal AF, shifting to the PBI strategy was feasible.

Long-Term Results of Radiofrequency Hot Balloon Ablation in Patients With Paroxysmal Atrial Fibrillation: Safety and Rhythm Outcomes.

INTRODUCTION: Isolation of pulmonary veins (PVs) and the posterior left atrium (LA) can be safely performed by radiofrequency hot balloon (RHB)-based box isolation. However, data on long-term effects for the treatment of atrial fibrillation (AF) by the use of this method remain limited. METHODS AND RESULTS: We treated 238 patients with paroxysmal AF (194 male; age. 62.6 ± 9.4 years) by RHB ablation. During 6.2-year (75 months) follow-up, 154 (64.7%) patients were free from atrial tachyarrhythmias (ATAs) without antiarrhythmic-drugs (AADs). We performed re-ablation in 69 of 84 patients with ATA recurrence (average 1.3 ± 0.6; median 1, total 91 procedures) using a 3D-mapping system and a conventional catheter. The sites of reconnection were observed at the PV in 61 of 69 (88.4%) patients and at the posterior LA in 58 of 69 (84.1%) patients. Finally, during mean follow-up of 4.6 ± 1.6 years, no-ATA episodes were detected in 201 (84.5%) patients without AADs. Independent predictors of ATA recurrence following a single procedure were heart failure with preserved ejection fraction (HR: 2.67, 95%CI: 1.40-5.10, P = 0.003) and low estimated glomerular filtration rate (HR: 1.81, 95%CI: 1.11-2.93, P = 0.03; cut-off of 62.0 mL/min/1.73 m(2)). During the follow-up period, there were 4 (1.7%) patients with PV stenosis (>70% reduction in PV diameter); however, none of these cases required intervention. Phrenic nerve palsy was detected in 8 patients (3.4%), but resolved during 3 months in all cases. CONCLUSION: RHB ablation can be effective during a long-term follow-up for patients with paroxysmal AF. Safety outcomes were within an acceptable range.

Prevalence of esophageal ulceration after atrial fibrillation ablation with the hot balloon ablation catheter: what is the value of esophageal cooling?

BACKGROUND: Little is known about luminal esophageal temperature (LET) monitoring during catheter ablation for atrial fibrillation (AF) using the radiofrequency hot balloon (RHB) technology. OBJECTIVE: The aim of this study is to investigate the impact of the use of a unique esophageal cooling method during RHB ablation. METHODS AND RESULTS: In this observational study, 318 consecutive patients (231 men; mean age, 63 ± 9 years) with symptomatic, drug-refractory, paroxysmal (n = 183) or persistent (n = 135) AF underwent RHB ablation with LET monitoring followed by a postprocedural, nonsymptom-driven esophageal endoscopy within 3 days of the ablation procedure. The patients have been divided into 3 groups. The first 22 patients treated are in Group A (n = 22) and had only LET monitoring without cooling of the esophagus. In Groups B (n = 128) and C (n = 168), patients had LET monitoring with cooling of the esophagus when the LET exceeded 43 °C and 39 °C, by infusion of cooled saline mixed with Gastrographin or Iopamidol, respectively. Group A had a higher risk of esophageal ulceration among the 3 groups (P < 0.0001). Saline infusion cooling initiated when the LET exceeded 43 °C (Group B) was not as safe as saline infusion cooling initiated when the LET exceeded 39 °C (Group C), demonstrated by the Group C minimum ulceration score and LET measurements while ablating the left superior pulmonary vein (LSPV) and left inferior pulmonary vein (LIPV) (P < 0.0001). CONCLUSION: Cooling the esophagus by a mix of Iopamidol and saline infusion when the LET exceeds 39 °C during RHB ablation may decrease the incidence and severity of esophageal thermal injury.

Feasibility of the radiofrequency hot balloon catheter for isolation of the posterior left atrium and pulmonary veins for the treatment of atrial fibrillation.

BACKGROUND: Atrial fibrillation originates mostly from the pulmonary vein (PV) foci or non-PV foci in the posterior left atrium (LA). The present study was designed to evaluate the feasibility and safety of a novel radiofrequency hot balloon catheter for the treatment of patients with atrial fibrillation by electrically isolating the posterior LA, including all PVs. METHODS AND RESULTS: One hundred consecutive patients with drug-resistant atrial fibrillation (63 paroxysmal, 37 persistent) were enrolled. The isolation of the PVs was performed by wedging the balloon at each PV antrum to create circumferential lesions in each case. Contiguous linear lesions were also created at the roof between the superior PVs and at the bottom of the posterior LA between the inferior PVs by dragging the balloon along the endocardium. Complete elimination of the posterior LA and PV potentials was achieved in all 100 cases, confirmed by either conventional or electro-anatomic mapping system. The total procedure time was 129+/-26 minutes, inclusive of 29.9+/-7.3 minutes of fluoroscopy time. Follow-up during 11.0+/-4.8 months confirmed that 92 patients (60 paroxysmal, 32 persistent) were free from atrial fibrillation without antiarrhythmic drugs, and in the remaining patients except for 2 with LA tachycardia, sinus rhythm was maintained with antiarrhythmic drugs. With precautions of esophageal cooling by irrigation dictated by temperature monitoring and monitoring phrenic nerve pacing, no LA-esophageal fistula or permanent phrenic nerve injury occurred. CONCLUSIONS: This feasibility study supports the safety and efficacy of radiofrequency hot balloon catheter for complete isolation of the posterior LA and PVs.

Usefulness of a new radiofrequency thermal balloon catheter for pulmonary vein isolation: a new device for treatment of atrial fibrillation.

INTRODUCTION: A rapidly firing or triggered ectopic focus located within a pulmonary vein (PV) or close to the PV ostium could induce atrial fibrillation (AF). The aim of this study was to evaluate the efficacy and safety of a radiofrequency thermal balloon catheter for isolation of the PV from the left atrium (LA). METHODS AND RESULTS: Twenty patients with drug-resistant paroxysmal AF were treated by isolating the superior PVs using an RF thermal balloon catheter. Using a transseptal approach, the balloon, which had an inflated diameter 5 to 10 mm larger than that of the PV ostium, was wedged at the LA-PV junction. It was heated by a very-high-frequency current (13.56 MHZ) applied to the coil electrode inside the balloon for 2 to 3 minutes, and the procedure was repeated up to four times. The balloon center temperature was maintained at 60 degrees to 75 degrees C by regulating generator output. Successful PV isolation was achieved in 19 of the 20 left superior PVs and in all 20 of the right superior PVs and was associated with a decrease in amplitude of the ostial potentials. Total procedure time was 1.8 +/- 0.5 hours, which included 22 +/- 7 minutes of fluoroscopy time. After a follow-up period of 8.1 +/- 0.8 months, 17 patients were free from AF, with 10 not taking any antiarrhythmic drugs and 7 taking the same antiarrhythmic agent as before ablation. Electron beam computed tomography revealed no complications, such as PV stenosis at ablation sites. CONCLUSION: The PV and its ostial region can be safely and quickly isolated from the LA by circumferential ablation around the PV ostia using a radiofrequency thermal balloon catheter for treatment of AF.

[Feasibility of combination mapping utilizing a duo-decapolar electrode catheter and the CARTO system for incisional reentrant atrial tachycardia with cycle length alternation: a case report].

A 43-year-old woman had undergone patch closure operation for atrial septal defect 27 years ago. She was referred to our hospital for evaluation of frequent palpitations since 1 year ago. Electrophysiological study was performed with recording of the coronary sinus, His bundle, and low lateral right free wall electrography utilizing a steerable duo-decapolar electrode catheter(Livewire, Daig). Supraventricular tachycardia with cycle length alternation of 300 and 320 msec similar to atrial flutter was reproducibly provoked by burst pacing from the coronary sinus. During the supraventricular tachycardia, abnormal atrial potentials occurred in the low lateral right free wall region with very low amplitude and splitting potentials. The cycle length alternation of the supraventricular tachycardia depended on the occurrence of the splitting potentials, that is, the splitting potentials were present during the supraventricular tachycardia with a long cycle and the splitting potentials were absent during the supraventricular tachycardia with a short cycle. This phenomenon suggested that the splitting potentials resulted from 2:1 functional intra-atrial local conduction block. In addition, during sinus rhythm the abnormal electrograms revealed fractionated activity. Thus, these findings strongly imply that the supraventricular tachycardia is due to a macro-reentrant right atrial tachycardia utilizing an anatomical obstacle caused by the atrial septal defect operation as a central area, namely incisional reentrant atrial tachycardia. Three-dimensional electroanatomical mapping using the CARTO system(Biosense-Webster) was conducted to investigate whether the low lateral right free wall area possessed the critical isthmus essential to the reentry circuit. Electroanatomical mapping revealed that the very low amplitude potentials and the splitting potentials corresponded to the scars and the functional conduction block area detected by mapping using the multipolar catheter, respectively. According to the propagation mapping, the incisional reentrant atrial tachycardia slowly conducted the channel created by multiple neighboring scars clockwise and the alternation of the tachycardia cycle length was dependent on the development of the functional local intra-atrial conduction block within the channel. An approximately 1.5 cm successful linear lesion was created by radiofrequency catheter ablation to transect the isthmus based on the electroanatomical mapping findings. Afterwards, the incisional reentrant atrial tachycardia could not be induced by burst stimuli from the coronary sinus even under administration of isoproterenol. The use of three dimensional electroanatomical mapping(CARTO system) to evaluate the reentry circuit after the detection of abnormal potentials by using multipolar catheter in advance is a very useful method to determine optimal target site of ablation for a patient with incisional reentrant atrial tachycardia.