Comparing cryoballoon and contact-force guided radiofrequency ablation in pulmonary vein isolation for atrial fibrillation in patients with hypertrophic cardiomyopathy.

BACKGROUND: Pulmonary vein isolation (PVI) employing cryoballoon (CB) or contact force-guided radiofrequency (CF-RF) catheter ablation has been established as an effective strategy for managing atrial fibrillation (AF). However, its efficacy in hypertrophic cardiomyopathy (HCM) remains to be further explored. METHODS: This retrospective study analyzed 60 consecutive AF patients with HCM (average age 67 ± 10 years; 41 men) who were consecutively admitted to our hospital from January 2014 to December 2022 and underwent initial PVI. RESULTS: The patients were treated with CB (26 patients) or CF-RF (34 patients). Successful PVI was achieved in both groups without significant complications. In the CF-RF group, additional ablations were performed on the cavotricuspid isthmus (14.7% of patients) and the anterior line (2.9%). The CB group benefited from reduced procedural times (93 ± 31 vs. 165 ± 60 min, p < 0.05) and decreased saline irrigation requirements (77.5 ± 31.4 vs. 870 ± 281.9 mL, p < 0.0001). Using a contrast medium was exclusive to the CB group (33.8 ± 4.2 mL). In a 12-month follow-up, the atrial tachyarrhythmia recurrence-free rates in the CB and CF-RF groups were comparable (77% and 76%, respectively; p = 0.63 according to the log-rank test). Notably, pulmonary vein reconnection was prevalent in most (7 out of 8) patients requiring a secondary ablation procedure. CONCLUSION: PVI is feasible as a strategy for AF in patients with HCM employing either CB or CF-RF techniques. While the recurrence-free rates were comparable in both groups, differences were noted in procedure duration, saline usage, and the need for a contrast medium.

Landiolol, an intravenous ß1-selective blocker, is useful for dissociating a fusion of atrial activation via accessory pathway and atrioventricular node.

Introduction: During ventricular pacing, a fusion of atrial activation may occur owing to the simultaneous retrograde conduction of the atrioventricular (AV) node and accessory pathway (AP), potentially leading to an inaccurate mapping of the atrial AP insertion site. Objective: We tested the hypothesis that landiolol, an ultra-short-acting intravenous ß1-blocker, could dissociate a fusion of atrial activation. Methods: We conducted a prospective before-and-after study to investigate the effect of landiolol on retrograde conduction via the AV node and AP. We enrolled 21 consecutive patients with orthodromic AV reciprocating tachycardia who underwent electrophysiological studies at our hospital between January 1, 2018, and August 31, 2020. Results: Six patients exhibited a fusion of atrial activation. After landiolol administration (10 µg/kg/min), the effective refractory period was unchanged in AP (280 [240-290] ms vs. 280 [245-295] ms, p = .91), whereas that of the AV node was prolonged (275 [215-380] ms vs. 332 [278-445] ms, p = .03). The Wenckebach pacing rate via retrograde AV node decreased after landiolol administration (180 [140-200] beats per minute [bpm] vs. 140 [120-180] bpm, p = .02). Thus, landiolol decreased the minimum ventricular pacing rate required to dissociate a fusion of atrial activation (180 [160-200] bpm vs. 140 [128-155] bpm, p = .007). Radiofrequency catheter ablation under landiolol administration successfully eliminated AP in all patients during ventricular pacing without complications or recurrence. Conclusion: Landiolol inhibited the AV node without affecting the AP and helped dissociate a fusion of atrial activation at a lower ventricular pacing rate.

Use of a QDOT MICRO catheter to identify a premature ventricular contraction origin in the right ventricular anterior papillary muscle in a repaired truncus arteriosus.

The ventricular papillary muscles (VPMs) can be a source of premature ventricular contractions (PVCs). Catheter ablation of VPM PVCs is challenging because of the anatomical complexity, such as the apical structures in proximity to the ventricular walls. The QDOT MICRO catheter (Biosense Webster, Diamond Bar, CA, USA) has microelectrodes embedded along the circumference of its distal tip and can provide information on which side of its tip myocardial activation is earlier. This repaired truncus arteriosus case demonstrates the usefulness of the microelectrode recording in identifying a PVC origin in a right VPM apex close to the right ventricular anterior wall.

Registry for Evaluating Healthy Life Expectancy and Long-Term Outcomes after Catheter Ablation of Atrial Fibrillation in the Very Elderly (REHEALTH AF) study: rationale and design of a prospective, multicentre, observational, comparative study.

INTRODUCTION: Data are lacking on the extent to which patients with non-valvular atrial fibrillation (AF) who are aged ≥80 years benefit from ablation treatment. The question pertains especially to patients' postablation quality of life (QoL) and long-term clinical outcomes. METHODS AND ANALYSIS: We are initiating a prospective, registry-based, multicentre observational study that will include patients aged ≥80 years with non-valvular AF who choose to undergo treatment by catheter ablation and, for comparison, such patients who do not choose to undergo ablation (either according to their physician's advice or their own preference). Study subjects are to be enrolled from 52 participant hospitals and three clinics located throughout Japan from 1 June 2022 to 31 December 2023, and each will be followed up for 1 year. The planned sample size is 660, comprising 220 ablation group patients and 440 non-ablation group patients. The primary endpoint will be the composite incidence of stroke/transient ischaemic attack (TIA) or systemic embolism (SE), another cardiovascular event, major bleeding and/or death from any cause. Other clinical events such as postablation AF recurrence, a fall or bone fracture will be recorded. We will collect standard clinical background information plus each patient's Clinical Frailty Scale score, AF-related symptoms, QoL (Five-Level Version of EQ-5D) scores, Mini-Mental State Examination (optional) score and laboratory test results, including measures of nutritional status, on entry into the study and 1 year later, and serial changes in symptoms and QoL will also be secondary endpoints. Propensity score matching will be performed to account for covariates that could affect study results. ETHICS AND DISSEMINATION: The study conforms to the Declaration of Helsinki and the Ethical Guidelines for Clinical Studies issued by the Ministry of Health, Labour and Welfare, Japan. Results of the study will be published in one or more peer-reviewed journals. TRIAL REGISTRATION NUMBER: UMIN000047023.

Initial multicenter clinical experience with the first-generation endoscopic guided laser balloon in Japan.

BACKGROUND: Isolation of the pulmonary veins (PVs) is the golden standard for atrial fibrillation (AF) ablation. To achieve a permanent PV isolation, the endoscopic guided HeartLight laser balloon system was invented. We analyzed the safety and efficacy of this laser balloon system. METHODS AND RESULTS: Three hundred four patients from 21 investigational sites inside Japan were enrolled in this study. One thousand sixty-two out of 1175 PVs (90.4%) were isolated using the HeartLight laser balloon. The isolation rate of the left superior, left inferior, right superior, and right inferior PVs was 87.8%, 91.3%, 91.6%, and 92.1%, respectively. The procedure time, defined as the time from the venous access to taking out the balloon, was 155 ± 39 min. The fluoroscopic time was 44 ± 25 min. The mean follow-up period was 309 ± 125 days. The freedom from AF recurrence at 3 months was 89.0% and at 12 months 82.1%. Adverse events occurred in 22 patients (7.2%) including phrenic nerve injury lasting more than 3 months in 1.6% and strokes in 1.0% of the patients. CONCLUSIONS: This initial experience demonstrated that the laser balloon ablation was feasible for PV isolation in Japanese AF patients.

Effect of Catheter Ablation for Atrial Fibrillation in Heart Failure With Mid-Range or Preserved Ejection Fraction　- Pooled Analysis of the AF Frontier Ablation Registry and Hokuriku-Plus AF Registry.

BACKGROUND: A recent randomized trial demonstrated that catheter ablation for atrial fibrillation (AF) in patients with heart failure with reduced ejection fraction (EF) is associated with a reduction in death or heart failure. However, the effect of catheter ablation for AF in patients with heart failure with mid-range or preserved EF is unclear.Methods and Results: We screened 899 AF patients (72.4% male, mean age 68.4 years) with heart failure and left ventricular EF ≥40% from 2 Japanese multicenter AF registries: the Atrial Fibrillation registry to Follow the long-teRm Outcomes and use of aNTIcoagulants aftER Ablation (AF Frontier Ablation Registry) as the ablation group (525 patients who underwent ablation) and the Hokuriku-Plus AF Registry as the medical therapy group (374 patients who did not undergo ablation). Propensity score matching was performed in these 2 registries to yield 106 matched patient pairs. The primary endpoint was a composite of cardiovascular death and hospitalization for heart failure. At 24.6 months, the ablation group had a significantly lower incidence of the primary endpoint (hazard ratio 0.32; 95% confidence interval 0.13-0.70; P=0.004) than the medical therapy group. CONCLUSIONS: Compared with medical therapy, catheter ablation for AF in patients with heart failure and mid-range or preserved EF was associated with a significantly lower incidence of cardiovascular death or hospitalization for heart failure.

Characterization of the PRAETORIAN score in Japanese patients undergoing subcutaneous implantable cardioverter-defibrillator implantation.

BACKGROUND: The PRAETORIAN score was developed to evaluate the implant position and predict defibrillation success in patients implanted with a subcutaneous implantable cardioverter-defibrillator (S-ICD). However, usefulness of the PRAETORIAN score for Japanese patients is unknown. METHODS: We evaluated usefulness of this score, which was determined by width of sub-coil fat, sub-generator fat, and anterior positioning of the S-ICD generator by post-operative chest X-ray, in consecutive 100 Japanese S-ICD implanted patients [78 men, median age 59 (IQR 46.5-67.0) years, median body mass index (BMI) 24.2 (21.3-27.2) kg/m2]. RESULTS: The median PRAETORIAN score was 30 (30-45) and 93 patients were classified as a low risk of conversion failure. The remaining seven were at an intermediate risk. Almost all patients were classified as an optimal pulse-generator position in the second and third steps of the PRAETORIAN score. The only difference observed was in the width of sub-coil fat in the first step. To further evaluate its significance, patients were divided into the Thicker group (sub-coil fat >1 coil width, n = 19) and the Thinner group (sub-coil fat ≤1 coil width, n = 81). BMI and post-shock impedance were both higher in the Thicker group than in the Thinner group [27.1 (25.6-31.6) versus 23.1 (20.9-25.7) kg/m2, p < 0.001, and 75 (68-88) versus 63 (55-74) Ω, p = 0.003, respectively]. During the median follow-up periods of 888 (523-1418) days, 7 patients experienced appropriate shock therapy for spontaneous ventricular tachyarrhythmias, who were all at a low risk. No conversion failure was observed. Inappropriate shock (IAS) occurred in 11 patients, and there was no difference in IAS rate between the Thicker group (n = 2) and the Thinner group (n = 9) (p = 0.747 by log-rank test). CONCLUSIONS: Most Japanese patients were classified as at low risk of conversion failure. The PRAETORIAN score may be useful for the evaluation of conversion failure in Japanese S-ICD implanted patients.

Event Monitoring and Evaluation by Community Pharmacists in Japan: A Pilot Study on Fenofibrate and Pemafibrate.

BACKGROUND: The Japan Pharmaceutical Association has conducted drug event monitoring to detect drug events related to pemafibrate. As there are a few studies on the safety of pemafibrate in clinical settings, a pilot study evaluating the association between drug use and detected events was performed in Japan. AIMS: In this study, the association between detected events and the use of pemafibrate, utilizing pharmacy records maintained by community pharmacists, was investigated. We identified the newuser cohort using a test and active comparison drug and collected the baseline information. An active comparison group comprising new users was used to assess the events. METHODS: A retrospective cohort study using questionnaires regarding baseline and event data was conducted by community pharmacists belonging to the Japan Pharmaceutical Association. The incidence of event and estimated hazard ratio were calculated using the Cox proportional hazards model that was adjusted for confounding factors, such as age and sex. RESULTS: A total of 1294 patients using pemafibrate and 508 patients using fenofibrate were identified as new drug users. The most reported events involving suspected adverse reactions and add-on drugs were increased blood pressure and lipid-lowering effects with pemafibrate use, and nasopharyngitis, pruritus, dizziness, and lipid-lowering effects with fenofibrate use. No significant differences were found in commonly occurring events, except that an add-on anti-hypertensive drug has been used by pemafibrate users compared to fenofibrate users. CONCLUSION: This study conducted by pharmacists can facilitate the safety assessment of newly marketed drugs, as few drug use investigations with a comparator are carried out by the Japanese authority for pharmaceutical companies. However, further research is required.

Cryoballoon ablation for paroxysmal atrial fibrillation in Japan: 2-year safety and efficacy results from the Cryo AF Global Registry.

PURPOSE: Catheter ablation is a recommended rhythm control therapy after failed or intolerant antiarrhythmic drug (AAD) treatment for patients with atrial fibrillation (AF). This study evaluates clinical performance and safety of pulmonary vein isolation (PVI) using the cryoballoon (Arctic Front Advance) in Japan. METHODS: Cryo AF Global Registry is a prospective, multi-center registry. Patients with paroxysmal AF (PAF) were treated at 10 Japanese hospitals. Efficacy was evaluated by freedom from a ≥ 30-s recurrence of AF/atrial flutter (AFL)/atrial tachycardia (AT), AF-related symptoms, and quality of life using the EQ-5D-3L questionnaire. The safety endpoint was serious device- and procedure-related adverse events. RESULTS: The study included 352 patients with PAF (65 ± 10 years of age, 36% female, 36% without prior failure of AAD). Mean duration since first diagnosis of AF was 3.0 ± 5.5 years. Serious device- and procedure-related adverse event rate was 2.6% (95% CI: 1.2-4.8%). Freedom from AF/AFL/AT was 88.5% (95% CI: 84.7-91.4%) at 12 months and 86.7% (95% CI: 81.1-90.8%) at 24 months. The number of patients with ≥ 1 AF symptom was significantly decreased from 88% at enrollment to 22% (p < 0.01) at 12-month follow-up. General quality of life using EQ-5D did not improve significantly after 12 months in the summary score. However, in the visual analog scale score, there was improvement (5.8 ± 18.4; p < 0.01). CONCLUSIONS: This study demonstrates that cryoablation used for PVI is a safe and effective treatment in real-world use for patients with PAF in Japan.

Contrast injection into the right atrial appendage apex using an external irrigation catheter for focal atrial tachycardia ablation.

Focal atrial tachycardias (ATs) originating from the right atrial appendage (RAA) apex are refractory to catheter ablation and can cause tachycardia-induced cardiomyopathy. After unsuccessful catheter ablation of these ATs, their elimination sometimes requires atrial appendectomy for treatment of tachycardia-induced cardiomyopathy. This case demonstrates that contrast injection into the RAA apex using an external irrigation catheter can facilitate mapping of such ATs and may provide safe and effective ablation of their sources even in the RAA tip.

Impact of sinus rhythm maintenance on major adverse cardiac and cerebrovascular events after catheter ablation of atrial fibrillation: insights from AF frontier ablation registry.

The impact of catheter ablation for atrial fibrillation (AF) on cardiovascular events and mortality is controversial. We investigated the impact of sinus rhythm maintenance on major adverse cardiac and cerebrovascular events after AF ablation from a Japanese multicenter cohort of AF ablation. We investigated 3326 consecutive patients (25.8% female, mean age 63.3 ± 10.3 years) who underwent catheter ablation for AF from the atrial fibrillation registry to follow the long-term outcomes and use of anti coagulants after ablation (AF frontier ablation registry). The primary endpoint was a composite of stroke, transient ischemic attack, cardiovascular events, and all-cause death. During a mean follow-up of 24.0 months, 2339 (70.3%) patients were free from AF after catheter ablation, and the primary composite endpoint occurred in 144 (4.3%) patients. The AF nonrecurrence group had a significantly lower incidence of the primary endpoint (1.8 per 100 person-years) compared with the AF recurrence group (3.0 per 100 person-years, p = 0.003). The multivariate analysis revealed that freedom from AF (hazard ratio 0.61, 95% confidence interval 0.44-0.86, p = 0.005) was independently associated with the incidence of the composite event. In the multicenter cohort of AF ablation, sinus rhythm maintenance after catheter ablation was independently associated with lower rates of major adverse cardiac and cerebrovascular events.

Different Determinants of the Recurrence of Atrial Fibrillation and Adverse Clinical Events in the Mid-Term Period After Atrial Fibrillation Ablation.

BACKGROUND: It is unclear whether there are differences in the clinical factors between atrial fibrillation (AF) recurrence and adverse clinical events (AEs), including stroke/transient ischemic attack (TIA), major bleeding, and death, after AF ablation.Methods and Results:We examined the data from a retrospective multicenter Japanese registry conducted at 24 cardiovascular centers between 2011 and 2017. Of the 3,451 patients (74.1% men; 63.3±10.3 years) who underwent AF ablation, 1,046 (30.3%) had AF recurrence and 224 (6.5%) suffered AEs (51 strokes/TIAs, 71 major bleeding events, and 36 deaths) over a median follow-up of 20.7 months. After multivariate adjustment, female sex, persistent and long-lasting persistent AF (vs. paroxysmal AF), and stepwise increased left atrial diameter (LAd) quartiles were significantly associated with post-ablation recurrences. A multivariate analysis revealed that an age ≥75 years (vs. <65 years), body weight <50 kg, diabetes, vascular disease, left ventricular (LV) ejection fraction <40% (vs. ≥50%), Lad ≥44 mm (vs. <36 mm), and creatinine clearance <50 mL/min were independently associated with AE incidences, but not with recurrences. CONCLUSIONS: This study disclosed different determinants of post-ablation recurrence and AEs. Female sex, persistent AF, and enlarged LAd were determinants of post-ablation recurrence, whereas an old age, comorbidities, and LV and renal dysfunction rather than post-ablation recurrence were AEs determinants. These findings will help determine ablation indications and post-ablation management.