The Japanese Catheter Ablation Registry (J-AB): Annual report in 2022.

The Japanese Catheter Ablation (J-AB) registry, started in August 2017, is a voluntary, nationwide, multicenter, prospective, observational registry, performed by the Japanese Heart Rhythm Society (JHRS) in collaboration with the National Cerebral and Cardiovascular Center. From January 2022, the data registration system was changed from Research Electronic Data Capture (REDCap) system to Fountayn system. The purpose of this registry was to collect the details of target arrhythmias, the ablation procedures, including the type of target arrhythmias, outcomes, and acute complications in the real-world settings. During the year of 2022, we have collected a total of 90,042 procedures (mean age of 66.7 years and 65.9% male) from 614 participant hospitals. Detailed data were shown in Figures and Tables.

Global Results of Implantable Loop Recorder for Detection of Atrial Fibrillation After Stroke: Reveal LINQ Registry.

BACKGROUND: We aimed to quantify the incidence of atrial fibrillation (AF) in patients with cryptogenic stroke globally, as well as separately in patients in and outside of Japan, using an implantable loop recorder from a prospective, observational, Reveal LINQ Registry. METHODS AND RESULTS: Patients developing cryptogenic stroke and monitored by implantable loop recorder for searching AF were studied. The primary end point was incidence of AF within 36 months after insertion. Secondary end points were recurrent ischemic stroke/transient ischemic attack and AF-related treatment strategies. A total of 271 patients (61.6±14.3 years, 170 men, 60 from Japan) were enrolled from 12 countries. AF was detected in 28.2% at 36 months. The median time from enrollment to AF detection was 7.9 months. During the first 12 months, the AF detection rate slope was relatively steeper in the Japanese subgroup versus non-Japanese patients. However, by 3 years, the cumulative incidence of AF detection did not differ between groups. Age was the only variable associated with AF detection (hazard ratio, 1.05 [95% CI, 1.02-1.07] per year), trending higher in older age groups. Of the 271 patients, 11 (4.1%) developed recurrent ischemic stroke/transient ischemic attack; AF was detected by implantable loop recorder in only 1 of these patients. Patients with detected AF were more commonly taking oral anticoagulation than those without AF at the last follow-up (64.7% versus 25.3%, P<0.001). CONCLUSIONS: The rate of AF detection was similar to other studies in stroke populations monitored by implantable loop recorders, including CRYSTAL-AF (Cryptogenic Stroke and Underlying Atrial Fibrillation), STROKE-AF (Stroke of Unknown Cause and Underlying Atrial Fibrillation) and PER-DIEM (Post-Embolic Rhythm Detection With Implantable Versus External Monitoring). Patients with detected AF more commonly initiated anticoagulation than those without AF.

Assessment of the safety and efficacy of catheter ablation for atrial fibrillation in very elderly patients: insight from the national prospective registry study.

BACKGROUND AND AIMS: This study evaluated the safety and efficacy of catheter ablation in treating atrial fibrillation (AF) among the elderly population. METHODS: A total of 170 017 AF ablation procedures prospectively enrolled from 482 facilities between 2017 and 2020 were analysed. They were stratified into six age groups, ranging from < 65 to ≥ 85 years, in 5-year increments. A cut-off of 80 years was set for dividing participants into two groups. The primary endpoints included procedure-related complications and 1-year arrhythmia recurrence after a 3-month blanking period. RESULTS: Patients ≥ 80 years constituted 7.2% of procedures in 2017, which significantly increased to 9.6% by 2020 (p < 0.001). This older group predominantly comprised women, with smaller stature and body mass index, a higher prevalence of paroxysmal AF, and a higher rate of initial ablation procedures. The overall complication rate was 2.8%, showing a positive correlation with age (p < 0.001), peaking at 4.3% for patients ≥ 85 years. Older age remained a significant independent risk factor for complications (odds ratio: 1.36 [1.24, 1.49], p < 0.001). Cardiac tamponade, ischemic stroke, and sick sinus syndrome were more common in the elderly. The recurrence rate in the total population was 16.0% and did not differ significantly between age groups (log-rank p = 0.473), remaining consistent even after adjusting for multiple variables. CONCLUSIONS: Although age increases complication risk, recurrence rates remained steady across age groups, suggesting that AF ablation is a reasonable option for elderly individuals, contingent on careful patient selection for safety. (ClinicalTrials.gov: NCT03729232).

Safety, efficacy, and quality of life outcomes of pulsed field ablation in Japanese patients with atrial fibrillation: results from the PULSED AF trial.

BACKGROUND: Pulsed field ablation (PFA), a novel treatment for atrial fibrillation (AF), has yet to be evaluated in a Japanese cohort. METHODS: In this sub-analysis of the PULSED AF trial, 12-month outcomes of paroxysmal AF (PAF) and persistent AF (PsAF) patients treated with PFA in four Japan centers were assessed. After a 90-day blanking period, primary efficacy was determined via freedom from a composite endpoint of acute procedural failure, arrhythmia recurrence, or antiarrhythmic drug escalation over 1 year. Patient improvement was evaluated via two quality of life (QoL) surveys (AFEQT and EQ-5D) at baseline and 12 months. RESULTS: The analysis included 32 patients, 16 PAF and 16 PsAF, with PAF patients averaging 61.1 ± 10.6 years and PsAF patients averaging 62.8 ± 11.5 years of age. Females made up 31% of PAF and 25% of PsAF cohorts. Acute pulmonary vein isolation was achieved in 100% of both cohorts. The primary efficacy success rate at 12 months was 75.0% for PAF and 56.3% for PsAF patients. No primary safety events occurred. The mean AFEQT score significantly increased for both PAF (25.9 points, p < 0.0001) and PsAF (13.2 points, p = 0.0002) patients, while the EQ-5D-5L score improved significantly for PAF (0.12 points, p = 0.048) patients but not for PsAF (0.04 points, p = 0.08) patients. CONCLUSIONS: Similar to outcomes in the global cohort, ablation with the PulseSelect™ PFA catheter was efficient, effective, and safe in a Japanese population, resulting in improved QoL for PAF and PsAF patients. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04198701.

Comprehensive review of pulmonary vein stenosis post-atrial fibrillation ablation: diagnosis, management, and prognosis.

Pulmonary vein stenosis (PVS) can occasionally occur in the follow-up after pulmonary vein isolation (PVI) for atrial fibrillation (AF). During PVI, ablation is performed at the PV ostium or distal part, leading to tissue damage. This damage can result in fibrosis of the necrotic myocardium, proliferation, and thickening of the vascular intima, as well as thrombus formation, further advancing PVS. Mild-to-moderate PVS often remains asymptomatic, but severe PVS can cause symptoms, such as dyspnea, cough, fatigue, decreased exercise tolerance, chest pain, and hemoptysis. These symptoms are due to pulmonary hypertension and pulmonary infarction. Imaging evaluations such as contrast-enhanced computed tomography are essential for diagnosing PVS. Early suspicion and detection are necessary, as underdiagnosis can lead to inappropriate treatment, disease progression, and poor outcomes. The long-term prognosis of PVS remains unclear, particularly regarding the impact of mild-to-moderate PVS over time. PVS treatment focuses on symptom management, with no established definitive solutions. For severe PVS, transcatheter PV angioplasty is performed, though the risk of restenosis remains high. Restenosis and reintervention rates have improved with stent implantation compared with balloon angioplasty. The role of subsequent antiplatelet therapy remains uncertain. Dedicated evaluation is essential for accurate diagnosis and appropriate management to avoid significant long-term impacts on patient outcomes.

Incidence of pulmonary vein stenosis in two types of cryoballoon systems.

Background: Currently, two types of cryoballoon (CB) systems are available for catheter ablation of atrial fibrillation (AF). Since the POLARx (Boston Scientific) is softer during freezing than the Arctic Front Advance Pro (AFA-Pro; Medtronic), it tends to go more deeply into the pulmonary vein (PV), risking PV stenosis. Methods: Ninety-one patients underwent initial CB ablation for paroxysmal AF (AFA-Pro 56; POLARx 35). Twenty-six from each group were extracted using propensity score matching. The PV cross-sectional area (PVA) was measured by tracing the area within the PV plane at 5-mm intervals from the PV ostium in a distal direction for 20 mm or to the bifurcation in each PV. The PVA was compared before and 3 months after ablation. Results: Time to balloon temperatures of -30 and - 40°C was significantly shorter and the nadir temperature was significantly lower with POLARx than with AFA-Pro. In the left inferior (LI) PV and right superior (RS) PV, the freezing balloon position was significantly deeper in POLARx than in AFA-pro. The freezing position in RSPV with mild to moderate narrowing was deeper than those without (10.2 ± 3.3 mm vs. 8.2 ± 1.8 mm, p = .01). In RSPV, the reduction of PVA tended to be greater with the POLARx than with the AFA-Pro (26.1% ± 14.1% vs. 19.9% ± 10.3%, p = .07). Conclusion: There was no significant difference in the incidence of PV stenosis between POLARx and AFA-Pro. However, if POLARx goes deep into the PVs, we will still have to be careful.

A meta-analysis and cost-minimization analysis of cryoballoon ablation versus radiofrequency ablation for paroxysmal atrial fibrillation.

Background: Previous studies have shown inconsistent results in clinical effectiveness between cryoballoon ablation (CBA) and radiofrequency ablation (RFA), and cost assessment between the procedures is important. The aim of this study was to evaluate the clinical effectiveness and cost-effectiveness between the procedures in patients with paroxysmal atrial fibrillation (AF) refractory to antiarrhythmic drug therapy. Methods: A systematic review and meta-analysis were performed. The primary outcome for the meta-analysis was long-term AF recurrence. Following the results of the meta-analysis, the cost-effectiveness of CBA versus RFA in Japan was assessed. Results: The meta-analysis included 12 randomized controlled trials and six propensity-score matching cohort studies. AF recurrence was slightly lower in patients referred for CBA than for RFA, with an integrated risk ratio of 0.93 (95% confidence interval: 0.81-1.07) and an integrated hazard ratio of 0.96 (95% confidence interval: 0.77-1.19), but no significant difference was found. A cost-minimization analysis was conducted to compare the medical costs of CBA versus RFA because there was no significant difference in the risk of AF recurrence between the procedures. The estimated costs for CBA and RFA were JPY 4 858 544 (USD 32 390) and JPY 4 505 255 (USD 30 035), respectively, with cost savings for RFA of JPY 353 289 (USD 2355). Conclusion: Our meta-analysis suggests that CBA provides comparable benefits with regard to AF recurrence compared with RFA, as shown in previous studies. Although the choice of treatment should be based on patient and treatment characteristics, RFA was shown that it might be cost saving as compared to CBA.

The association between hyperuricemia and atrial fibrillation recurrence after catheter ablation.

Background: Hyperuricemia (HU) has been reported to be associated with a high incidence of atrial fibrillation (AF). However, the relationship between HUA and recurrent AF after catheter ablation (CA) is unclear. Methods: Four hundred consecutive AF patients (paroxysmal/persistent AF [PAF/PsAF]: 200/200) who underwent the initial CA were retrospectively enrolled. HU was defined as serum uric acid (SUA) level >7.0 mg/dL. We measured SUA levels 1 day before (pre-CA) and 1 month after CA (post-CA). A second-generation 28 mm cryoballoon was used for pulmonary vein isolation (PVI) for PAF, while PVI plus linear ablation (roof and mitral isthmus lines) by radiofrequency catheter was conducted for PsAF. Results: During 57 ± 24 months of follow-up, AF recurred in 16% and 42% in PAF and PsAF patients (p < .0001). Pre-CA SUA level in PsAF was significantly higher than that in PAF (6.5 ± 1.3 vs. 5.8 ± 1.3 mg/dL, p < .001). SUA level was significantly decreased after CA in both PAF and PsAF (5.8 ± 1.3 vs. 5.6 ± 1.3 mg/dL; p < .01 and 6.5 ± 1.3 vs. 6.1 ± 1.2 mg/dL; p < .0001, respectively). The association between pre-/post-CA HU and recurrent AF was not identified in PAF, while the incidence of post-CA HU was significantly higher in patients with recurrent AF than those without in PsAF (36% vs. 15%, p < .001). In multivariable analysis, longer AF duration and the presence of post-CA HU were identified as independent predictors of AF recurrence in PsAF (OR:1.01, 95%CI:1.003-1.011, p = .0001 and OR:2.77, 95%CI:1.333-5.755, p = .007, respectively). Conclusions: SUA level was significantly higher in PsAF than PAF patients. The presence of post-CA HU was strongly related to AF recurrence in PsAF patients.

Prevalence, timing, and impact of early recurrence of atrial tachyarrhythmias after pulsed field ablation: A secondary analysis of the PULSED AF trial.

BACKGROUND: Early recurrence of atrial tachyarrhythmias (ERAT) within 3 months of thermal ablation for atrial fibrillation (AF) is common and often considered transient. Pulsed field ablation (PFA) is a nonthermal energy source in which ERAT is not well described. OBJECTIVE: The purpose of this study was to analyze ERAT in patients with AF undergoing PFA in the Pulsed Field Ablation to Irreversibly Electroporate Tissue and Treat AF (PULSED AF) trial. METHODS: This analysis included 154 (52.4%) paroxysmal AF and 140 (47.6%) persistent AF who had ≥10 rhythm assessments during the 90-day blanking period. ERAT was defined as any instance of ≥30 seconds of AF, atrial flutter, or atrial tachycardia on transtelephonic monitoring (weekly and symptomatic) or ≥10 seconds on electrocardiography (at 3 months), both within 90 days. Late recurrence of atrial tachyarrhythmias (LRAT) was defined as observed atrial tachyarrhythmias between 90 days and 12 months. RESULTS: The overall prevalence of ERAT was 27.1% in patients with paroxysmal AF and 31.6% in patients with persistent AF. In patients with ERAT, 73% had ERAT onset within the first month of the procedure. The presence of ERAT was associated with LRAT in patients with paroxysmal AF (hazard ratio 6.4; 95% confidence interval 3.6-11.3) and patients with persistent AF (hazard ratio 3.8; 95% confidence interval 2.2-6.6). Yet, in 29.4% of patients with paroxysmal AF and 34.3% of patients with persistent AF with ERAT, LRAT was not observed. LRAT was positively correlated with the number of ERAT observations. CONCLUSION: ERAT after PFA predicted LRAT in patients with paroxysmal and persistent AF. However, the concept of a blanking period after PFA is still valid, as approximately one-third of patients with ERAT did not continue to have LRAT during follow-up and may not need reablation.

Changes in pulmonary vein size and narrowing depend on the cardiac cycle before and after pulmonary vein isolation.

Accurate measurement of the pulmonary vein dimension (PVD) is important for determining stenosis and efficacy following pulmonary vein isolation (PVI). Little is known about the quantitative evaluation of the impact of the cardiac cycle on pulmonary vein (PV) morphology before and after PVI. This study aims to investigate variations in the ostial size of the PV during the cardiac cycle before and after PVI and the effect of the cardiac cycle on PV stenosis and reduction rate using cardiac computed tomography (CT). Sixty-eight patients with atrial fibrillation who underwent cardiac CT before and after PVI at our institution between 23 January 2021 and 5 February 2022 were retrospectively analyzed. The maximum and minimum PVD were measured at each segment before and after the PV. Each PV was evaluated according to the PVD reduction rate (ΔPVD), calculated as follows: (1 - post-PVD/pre-PVD) × 100 (%). The average dimension of all PVs at the end-diastolic frame was significantly reduced compared to that at the end-systolic frame before PVI. The average dimensions of the right superior and right inferior PV at the end-diastolic frame were significantly reduced compared with those at the end-systolic frame following PVI. The average reduction rate of dimension-classified stenosis of PVs, except for the left inferior PV at the end-diastolic frame, was significantly reduced compared with that at the end-systolic frame. The cardiac cycle affects PVD assessment, including PV stenosis, after PVI. PVD measurement is recommended to be unified to the end-systolic frame of the cardiac cycle to avoid underestimating PV stenosis before and after PVI, ensuring appropriate management and follow-up.

A rare case of modified superior vena cava isolation by using the ultra-high-resolution mapping system.

We report a case of atrial fibrillation (AF) recurrence after pulmonary vein isolation, which patient had AF trigger in the superior vena cava (SVC) near the sinus node (SN). The ultra-high-resolution mapping revealed that SN located within the SVC and the atrial activation from the SN to SVC propagated in both septal and lateral direction, then upward with circumventing the spontaneous conduction block identified just above and lateral SN (upper hemisphere). We successfully isolated SVC including the ectopic origin at the same level as the SN by utilizing the spontaneous conduction block line around the SN without any complication.

The Japanese Catheter Ablation Registry (J-AB): Annual report in 2021.

The Japanese Catheter Ablation (J-AB) registry, started in August 2017, is a voluntary, nationwide, multicenter, prospective, observational registry, performed by the Japanese Heart Rhythm Society (JHRS) in collaboration with the National Cerebral and Cardiovascular Center using a Research Electronic Data Capture system. The purpose of this registry is to collect the details of target arrhythmias, the ablation procedures, including the type of target arrhythmias, outcomes, and acute complications in the real-world settings. During the year of 2021, we have collected a total of 89 609 procedures (mean age of 66.1 years and 65.9% male) from 506 participant hospitals. Detailed data are shown in Figures and Tables.

Balloon surface temperature-controlled ablation using a second-generation radiofrequency HotBalloon: an in vivo feasibility study.

AIMS: The first-generation radiofrequency HotBalloon (RHB) is a size-adjustable single-shot device used in atrial fibrillation. The energy output is determined by its central temperature and not by its balloon surface temperature (BST), thus limiting its efficacy and safety. Therefore, a second-generation RHB was developed to monitor BST and enable BST-controlled ablation. This animal study aims to evaluate the accuracy of a newly developed BST-monitoring system and validate the optimal BST for ablation. METHODS AND RESULTS: In Protocol 1, thermocapsules were attached to the superior vena cava (SVC) epicardium. The accuracy of BST monitoring was examined during SVC isolation. In Protocol 2, the efficacy and safety of different BST-controlled ablations were examined. In the acute model, electrophysiological and pathological findings were assessed after energy applications with BST at 51, 54, 57, and 60°C. In the chronic model, the lesion durability and pathological findings were assessed 8 weeks after BST-controlled ablation (57 and 60°C). A significant positive correlation was found between the epicardial temperature and the BST-monitoring value (r = 0.98). In the acute model, all target veins were electrically isolated with BST-controlled ablation at ≥57°C (18/18, 100%). In the chronic model, durable lesions were observed in all veins at 60°C, while 44% of the veins showed reconnection at 57°C. In both pathological analyses, significantly greater lesions were observed at 60°C than at 57°C. There were no significant differences in adverse events between the two groups. CONCLUSION: Balloon surface temperature-controlled ablation at 60°C using the second-generation RHB may be optimal for creating durable lesions without compromising safety.

Idarucizumab for Emergency Reversal of the Anticoagulant Effects of Dabigatran: Final Results of a Japanese Postmarketing Surveillance Study.

INTRODUCTION: Idarucizumab, a monoclonal antibody fragment that rapidly reverses the anticoagulant effects of dabigatran, was approved in Japan in September 2016, at which time an all-case, postmarketing surveillance (PMS) study was initiated to collect data on idarucizumab in Japanese patients. Interim results were published previously, and the final results are reported herein. METHODS: This multicenter, open-label, uncontrolled, non-interventional PMS study was conducted in Japanese patients who received idarucizumab at the approved dose (2 × 2.5 g/50 ml) and had uncontrolled bleeding (group A) or required an emergency procedure (group B). The primary endpoint was the frequency of adverse drug reactions (ADRs). The secondary endpoint was the maximum extent of reversal of the anticoagulant effects of dabigatran, within 4 h of idarucizumab administration, based on activated partial thromboplastin time (aPTT). RESULTS: The final analysis included 804 patients. ADRs during the idarucizumab treatment and post-treatment periods were reported in 17 of 542 patients (3.1%) in group A and 12 of 240 patients (5.0%) in group B. Thrombotic events were reported in 22 patients (4.1%) in group A and 15 patients (6.3%) in group B, and hypersensitivity occurred in four (0.7%) and five patients (2.1%), respectively. Among 793 patients evaluated for effectiveness, 78 in group A and 26 in group B had aPTT data at baseline (immediately before idarucizumab administration) and within 4 h of idarucizumab administration; in these patients, median maximum percentage reversal within 4 h of idarucizumab administration was 100%. CONCLUSIONS: The final analysis from the PMS study confirms previous findings suggesting that idarucizumab can safely and effectively reverse the anticoagulant effects of dabigatran in Japanese patients in clinical practice. The results support the continued use of idarucizumab in Japan. TRIAL REGISTRATION: This study is registered with ClinicalTrials.gov (NCT02946931).

Atrial fibrillation is an irregular heart rhythm (arrhythmia), and the type of atrial fibrillation not caused by a heart valve problem is known as "non-valvular atrial fibrillation" or NVAF. People with NVAF have an increased risk of ischemic stroke, in which a blood clot (thrombus) blocks an artery in the brain. Drugs that inhibit blood clots, known as anticoagulants, are prescribed to people with NVAF to prevent ischemic stroke. Historically, warfarin has been one of the most prescribed anticoagulant drugs. However, a novel anticoagulant drug, known as dabigatran, has clinical advantages over warfarin and is approved in many countries for people with NVAF. People who take anticoagulants may experience life-threatening bleeding or need urgent surgery, and thus rapid and effective reversal of the anticoagulant effects is critical. The drug idarucizumab specifically binds to dabigatran to reverse its anticoagulant effects in people with uncontrolled bleeding or who require an urgent procedure. Idarucizumab was approved for use in Japan in September 2016. In Japan, drug companies are obligated to collect data after a new drug is launched as an approval condition, which is done through a postmarketing surveillance study. Here, we report the final results of a postmarketing surveillance study conducted between September 2016 and November 2020 to evaluate the safety and effectiveness of idarucizumab in Japanese patients receiving dabigatran. The results of our study show that idarucizumab can safely and effectively reverse the anticoagulant effects of dabigatran in Japanese patients, and support the continued use of idarucizumab in Japan in clinical practice.

Pulmonary Vein Stenosis After Catheter Ablation of Atrial Fibrillation Using a Cryoballoon, Hot Balloon, or Laser Balloon.

BACKGROUND: Pulmonary vein stenosis (PVS) after PV isolation (PVI) for atrial fibrillation (AF) is a severe complication that requires angioplasty. This study aimed to compare the reduction of the cross-sectional PV area (PVA) and the incidence of PVS after cryoballoon (CB)-PVI, hot balloon (HB)-PVI, or laser balloon (LB)-PVI.Methods and Results: A total of 320 patients who underwent an initial catheter ablation procedure for AF using a CB, HB, or LB in 2 hospitals were included. They underwent contrast-enhanced multidetector CT before and 3 months after the procedure. In all 4 PVs, the reduction in PVA was more significant in the LB group than in the CB or HB groups, respectively. Moderate (50-75%) and severe (>75%) PVS were observed in 5.3% and 0.5% of the PVs, respectively. Although moderate PVS was more frequently observed in the LB group than in the CB or HB groups (8.2%, 3.8%, and 5.0%; P=0.03), the incidence of severe PVS was similar in the LB, CB, and HB groups (0.3%, 0.5%, and 1.0%; P=0.46). Symptomatic PVS requiring intervention occurred in 1 (0.3%) patient. CONCLUSIONS: Although the reduction in cross-sectional PVA and the incidence of moderate PVS after LB-PVI was more significant than after CB-PVI or HB-PVI, it rarely led to severe PVS. Symptomatic PVS requiring intervention was rare after the balloon ablation of AF.