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.

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).

Intermittent hypoxia by obstructive sleep apnea is significantly associated with electro-anatomical remodeling of the left atrium preceding structural remodeling in patients with atrial fibrillation.

Background: Obstructive sleep apnea (OSA) is one of the risk factors for atrial fibrillation (AF). However, the mechanism underlying the atrial structural and electro-anatomical remodeling by OSA has not yet been clearly elucidated. Methods: This study was conducted in 83 patients who had undergone catheter ablation for AF (49 with OSA and 34 Controls without OSA). The left atrial (LA) maps were created in all the patients using a three-dimensional electro-anatomical mapping system. The LA with a bipolar voltage of <0.5 mV was defined as the low voltage area (LVA); %LVA was defined as the ratio of the LVA to the total surface area of the LA. Results: The LVA and %LVA were significantly greater in the OSA group as compared with the Control group, however, there was no difference in the LA area. The 3 % oxygen desaturation index (ODI) was significantly correlated with the %LVA (r = 0.268, P = 0.014), but not with the LA area. Multiple regression analysis with adjustments identified 3 %ODI ≥30 (3.088, 1.078-8.851, P = 0.036) as being significantly associated with the %LVA. Conclusions: In patients with AF complicated by OSA, significant increase of the LVA, but not of the LA area, was observed. The intermittent hypoxia severity was significantly associated with the LVA. These results suggest that intermittent hypoxia by OSA might be one of the mechanisms of electro-anatomical remodeling of the LA, possibly preceding structural remodeling represented by LA enlargement, in patients with AF.

Adverse events associated with early initiation of Eplerenone in patients hospitalized for acute heart failure.

BACKGROUND: The guidelines recommend the initiation or up-titration of heart failure (HF) treatments following an HF hospitalization; however, concerns about adverse events may limit the use of mineralocorticoid receptor antagonists (MRAs). Patient profiles or disease severity might impact adverse events associated with MRA therapy in acute HF. METHODS: The EARLIER trial included patients with acute HF who were randomized to eplerenone or placebo over 6 months. Adverse events (i.e., worsening renal function [WRF], hyperkalemia, hypotension, and volume depletion/dehydration) were assessed. HF-related outcome included a composite of all-cause mortality, HF re-hospitalization, investigator-reported worsening HF and out-of-hospital diuretic intensification. RESULTS: In 297 patients (mean age: 67 ± 13 years; 73% males), adverse events were observed: 44.4% experienced WRF (>20% drop in estimated glomerular filtration rate[eGFR] and/or investigator-reported WRF), 8.4% had hyperkalemia (potassium >5.5 mmol/L and/or investigator-reported hyperkalemia), 27.9% experienced hypotension (systolic blood pressure[SBP] <90 mmHg and/or investigator-reported hypotension), and 16.8% had investigator-reported volume depletion/dehydration. Eplerenone vs. placebo did not elevate the incidence of these events (all-p-values>0.0 5). Multivariable analyses revealed that, irrespective of treatment allocation, older age (>7 5 years), prevalent diabetes, symptomatic congestion, and microalbuminuria were associated with increased risk of WRF. Baseline eGFR<60 ml/min/1.73m2 and SBP < 90 mmHg predicted hyperkalemia and hypotension, respectively, while older patients were more likely to experience volume depletion/dehydration. However, these patient profiles did not alter the benefit of eplerenone on outcomes (HR [9 5%CI] = 0.53 [0.29 to 0.97], P = 0.04; all-p-for-interaction>0.10). CONCLUSION: Eplerenone did not increase adverse events compared with placebo in acute HF. Importantly, disease severity and comorbidity burden greatly influence adverse events, but not benefit from eplerenone.

Artificial intelligence-derived left ventricular strain in echocardiography in patients treated with chemotherapy.

Global longitudinal strain (GLS) is an echocardiographic measure to detect chemotherapy-related cardiovascular dysfunction. However, its limited availability and the needed expertise may restrict its generalization. Artificial intelligence (AI)-based GLS might overcome these challenges. Our aims are to explore the agreements between AI-based GLS and conventional GLS, and to assess whether the agreements were influenced by expertise levels, cardiac remodeling and cardiovascular diseases/risks. Echocardiographic images in the apical four-chamber view of left ventricle were retrospectively analyzed based on AI-based GLS in patients treated with chemotherapy, and correlation between AI-based GLS (Caas Qardia, Pie Medical Imaging) and conventional GLS (Vivid E9/VividE95, GE Healthcare) were assessed. The agreement between unexperienced physicians ("GLS beginner") and experienced echocardiographer were also assessed. Among 94 patients (mean age 69 ± 12 years, 73% female), mean left ventricular ejection fraction was 64 ± 6%, 14% of patients had left ventricular hypertrophy, and 21% had left atrial enlargement. Mean GLS was - 15.9 ± 3.4% and - 19.0 ± 3.7% for the AI and conventional method, respectively. There was a moderate correlation between these methods (rho = 0.74; p < 0.01), and bias was - 3.1% (95% limits of agreement: -8.1 to 2.0). The reproducibility between GLS beginner and an experienced echocardiographer was numerically better in the AI method than the conventional method (inter-observer agreement = 0.82 vs. 0.68). The agreements were consistent across abnormal cardiac structure and function categories (p-for-interaction > 0.10). In patients treated with chemotherapy. AI-based GLS was moderately correlated with conventional GLS and provided a numerically better reproducibility compared with conventional GLS, regardless of different levels of expertise.

Feasibility of a novel atrial mechanical sensing method for leadless atrioventricular synchronous pacing.

INTRODUCTION: Few studies have demonstrated a high degree of atrioventricular (AV) synchrony with a new leadless pacemaker called Micra AV. Our group previously reported a new and unique sensing method. We believe that this novel sensing method, "Simplified A3 method," might facilitate better AV synchrony than a conventional sensing method in almost all cases with Micra AV implantation. METHODS: We conducted a non-randomized retrospective study comparing the two pacing methods at two centers. From December 1, 2021 to October 31, 2022, Micra AV was implanted for 32 patients at the two centers. Twenty of the 32 patients with sinus rhythm and complete AV block were included in this study. In Group 1, the conventional setting was programmed as follows: auto A3 threshold, auto A3 window-end (WE), and auto A4 threshold turned on during hospitalization. In Group 2, the "Simplified A3 method" was programmed as follows: auto A3 threshold and auto A3WE turned off. Instead, an intentionally prolonged A3WE (850-1000 ms) and low A3 threshold (A3 signal amplitude + 0.5-1.0 m/s2) were programmed. RESULTS: Twenty patients were analyzed. In Group 2, AV synchrony (%AMVp) was significantly higher at the first outpatient clinic (63.0 ± 5.7% vs 81.0 ± 4.2%, p = .03). A3 threshold was significantly lower in Group 2 (5.9 ± 0.7 m/s2, p < .05 vs 2.3 ± 0.5 m/s2, p < .05). CONCLUSION: Our novel sensing method might be a more feasible sensing method for obtaining higher AV synchrony than the conventional algorithm.

A case of cardiac sarcoidosis mimicking acute phase of takotsubo cardiomyopathy evaluated by multimodality cardiac imaging.

The patient was a 68-year-old woman who experienced loss of consciousness owing to a seizure while walking and bruised her face. Twelve­lead electrocardiography displayed a complete atrioventricular block. Transthoracic echocardiography displayed hypokinesis from the middle to apex of the myocardium. Emergency coronary angiography displayed no clear stenosis of the coronary arteries, and left ventriculography displayed takotsubo-like abnormal left ventricular wall motion. 99mTc-sestamibi/123I-beta-methyl iodophenyl pentadecanoic acid dual single-photon emission computed tomography displayed a perfusion/metabolism mismatch in the left apex, anterior segment, and inferior segment of the myocardium in the acute phase, which improved in the chronic phase. Similar mismatch findings were observed in the ventricular septum, which persisted in the chronic phase. Blood biomarkers of sarcoidosis were positive. Myocardial delayed enhancement was observed in the mid layer of the basal septum and inferior wall on cardiac magnetic resonance imaging. Fluorodeoxyglucose-positron emission tomography displayed signal accumulation in the basal septum. The clinical course of the patient suggested the possibility of cardiac sarcoidosis combined with takotsubo cardiomyopathy. This is a valuable case in which changes over time were detected by multimodality cardiac imaging. Learning objective: Cardiac manifestations of both takotsubo cardiomyopathy and sarcoidosis are similar, with both causing abnormal left ventricular wall motion. The co-occurrence of these conditions has been seldomly reported to date. The similarity of the characteristics of each condition poses a challenge in the diagnostic process. The utilization of multimodality cardiac imaging techniques, as demonstrated in the present case, is an effective means of establishing a diagnosis.

Pediatric hypertrophic cardiomyopathy caused by a novel TNNI3 variant.

TNNI3 is a gene that causes hypertrophic cardiomyopathy (HCM). A 14-year-old girl who was diagnosed with nonobstructive HCM presented with cardiopulmonary arrest due to ventricular fibrillation. Genetic testing revealed a novel de novo heterozygous missense variant in TNNI3, NM_000363.5:c.583A>T (p.Ile195Phe), which was determined to be the pathogenic variant. The patient exhibited progressive myocardial fibrosis, left ventricular remodeling, and life-threatening arrhythmias. Genetic testing within families is useful for risk stratification in pediatric HCM patients.

Diagnostic performance of pressure-bounded coronary flow reserve.

Fluid dynamics studies have proposed that coronary flow reserve can be calculated from coronary artery pressure instead of coronary blood flow. We sought to investigate the diagnostic performance of pressure-bounded coronary flow reserve (pb-CFR) compared with CFR measured by conventional thermodilution method (CFRthermo) in the clinical setting. Pressure guidewire was used to measure CFRthermo and fractional flow reserve (FFR) in left anterior descending coronary artery in 62 patients with stable coronary artery disease. Pb-CFR was calculated only with resting distal coronary artery pressure (Pd), resting aortic pressure (Pa) and FFR. Pb-CFR was moderately correlated with CFRthermo (r = 0.54, P < 0.001). Pb-CFR showed a poor agreement with CFRthermo, presenting large values of mean difference and root mean square deviation (1.5 ± 1.4). Pb-CFR < 2.0 predicted CFRthermo < 2.0 with an accuracy of 79%, sensitivity of 83%, specificity of 78%, positive predictive value of 48%, negative predictive value of 95%. The discordance presenting CFRthermo < 2.0 and pb-CFR ≥ 2.0 was associated with diffuse disease (P < 0.001). The discordance presenting CFRthermo ≥ 2 and pb-CFR < 2 was associated with a high FFR (P = 0.002). Pb-CFR showed moderate correlation and poor agreement with CFRthermo. Pb-CFR might be reliable in excluding epicardial coronary artery disease and microcirculatory disorders.

Central Systolic Blood Pressure as a Risk Factor for Accelerated Progression of Arterial Stiffness.

AIMS: In the arterial tree, a pressure gradient of the systolic blood pressure (SBP) is observed from the center to the periphery, with the pressure being higher in the periphery because of pressure wave reflection. However, this gradient is attenuated, with elevation of the central SBP (cSBP), in cases with abnormal pressure wave reflection in the arterial tree. It remains unclear if increase of the cSBP might be an independent risk factor for accelerated progression of arterial stiffness. We conducted this prospective observational study using latent growth curve model (LGCM) analyses to examine if elevated cSBP might be an independent risk factor for accelerated progression of the arterial stiffness in middle-aged Japanese men. METHODS: In this 9-year prospective observational study, we analyzed the data of 3862 middle-aged Japanese men (43±10years old) without cerebrocardiovascular disease at the study baseline who had undergone repeated annual measurements of the brachial-ankle pulse wave velocity (baPWV) and cSBP, as represented by the second peak of the radial pressure waveform (SBP2) in radial pressure waveform analysis. RESULTS: During the follow-up period (6.3±2.5years), significant increases of both the baPWV and SBP2 were observed in all the subjects. Analysis using the LGCM confirmed that the SBP2, a marker of the cSBP (B=0.260, P＜0.001), was a significant determinant of the slope of the annual changes of the baPWV during the study period. CONCLUSIONS: Our finding may appear to confirm elevated cSBP as an independent risk factor for accelerated progression of the arterial stiffness in middle-aged Japanese men.

Second Micra leadless pacemaker implantation by using intracardiac echocardiography.

The strategy after battery depletion was not established in Micra leadless pacemaker system (Micra). There are still some concerns in the 2nd Micra implantation, such as the mechanical interaction between both devices. The position of the 2nd Micra should be placed apart from the 1st Micra. We present a case of 1st Micra battery depletion who successfully underwent the 2nd Micra implantation under the intracardiac echo guidance. In our case, intracardiac echo was a very effective tool for confirming the location of Micra implantation.

Nutritional Status and Sleep Quality Are Associated with Atrial Fibrillation in Patients with Obstructive Sleep Apnea: Results from Tokyo Sleep Heart Study.

The prevalence of obstructive sleep apnea (OSA) in patients with atrial fibrillation (AF) has been observed to be much higher than in control participants without AF. Limited data exist regarding the prevalence of AF in patients with OSA. The clinical characteristics, nutritional status, and sleep parameters associated with AF in patients with OSA remain unclear. In this study, we aimed to determine the prevalence and factors associated with AF in patients with OSA from a large Japanese sleep cohort (Tokyo Sleep Heart Study). This was a single-center explorative cross-sectional study. Between November 2004 and June 2018, we consecutively recruited 2569 patients with OSA who underwent an overnight full polysomnography at our hospital. They were assessed using a 12-lead ECG and echocardiography. The clinical characteristics, sleep parameters, and medical history were also determined. Of the OSA patients, 169 (6.6%) had AF. Compared with the non-AF patients, OSA patients with AF were older and male, and they had higher prevalence of a history of alcohol consumption, hypertension, chronic kidney disease, and undernutrition, as well as a reduced ejection fraction. With regard to the sleep study parameters, OSA patients with AF had reduced slow-wave sleep and sleep efficiency, as well as higher periodic limb movements. There were no significant differences in the apnea-hypopnea index or hypoxia index between the two groups. The logistic regression analysis demonstrated that age (OR = 4.020; 95% CI: 1.895-8.527; p < 0.001), a history of alcohol consumption (OR = 2.718; 95% CI: 1.461-5.057; p = 0.002), a high CONUT score (OR = 2.129; 95% CI: 1.077-4.209; p = 0.030), and reduced slow-wave sleep (OR = 5.361; 95% CI: 1.505-19.104; p = 0.010) were factors significantly related to AF. The prevalence of AF in patients with OSA was 6.6%. Age, a history of alcohol consumption, undernutrition, and reduced sleep quality were independent risk factors for the presence of AF in patients with OSA, regardless of the severity of OSA.

Case report: successful termination of ventricular tachycardia by intrinsic anti-tachycardia pacing beyond conventional anti-tachycardia pacing.

Background: Anti-tachycardia pacing (ATP) is a pain-free alternative to defibrillation shock for monomorphic ventricular tachycardia (VT). Intrinsic ATP (iATP) is a novel algorithm of auto-programmed ATP. However, the advantage of iATP over conventional ATP in clinical cases is still unknown. Case summary: A 49-year-old man with no significant past medical history was transferred to our institution with sudden-onset fatigue from working on a farm. A 12-lead electrocardiogram showed monomorphic sustained wide QRS tachycardia with a right bundle branch block pattern and superior axis deviation with a cycle length (CL) of 300 ms. Sustained monomorphic VT originating from the left ventricle due to underlying vasospastic angina was diagnosed by contrast-enhanced cardiac magnetic resonance imaging, coronary angiography, and the acetylcholine stress test, and implantable cardioverter defibrillator implantation was performed. Nine months later, a clinical VT episode with a CL of 300 ms was observed, which could not be terminated by three sequences of conventional burst pacing. Ventricular tachycardia was finally terminated by a third iATP sequence without any acceleration. Discussion: Although standard burst pacing by conventional ATP reached the VT circuit, it failed to terminate the VT. Using the post-pacing interval, iATP automatically calculated the appropriate number of S1 pulses required to reach the VT circuit. In iATP, the S2 pulses are delivered with a calculated coupling interval based on the estimated effective refractory period during tachycardia. In this case, iATP might have led to less aggressive S1 stimulation, followed by aggressive S2 stimulation, which probably helped terminate the VT without any acceleration.

A case of short-coupled variant of Torsade de Pointes with bystander early repolarization in inferior leads.

The presence of J waves in cases of ventricular fibrillation (VF) is known to be a risk for sudden cardiac death. Recently, the effectiveness of radiofrequency catheter ablation (RFCA) for early repolarization syndrome (ERS) has been reported.The patient is a 30-year-old male with elevated J waves of 0.1 mV in the inferior leads, who had previously developed VF and undergone implantable cardioverter defibrillator (ICD) implantation. Because the VF from short coupled premature ventricular contraction (PVC) was presented, the RFCA of the triggered PVC was attempted. But it was unsuccessful due to no inducibility of the triggered PVC. After that, despite anti-arrythmia drug treatment, appropriate ICD shock for VF was observed. Although we decided to do a second ablation and evaluated epicardial arrhythmia substrate, no specific findings of early repolarization syndrome were found in the electrophysiological study. Finally, we considered that the cause of VF was short-coupled variant of Torsade de Pointes, and PVC ablation was performed. VF has not occurred since. We consider that this is a rare case to evaluate the epicardial arrhythmogenic substrate of J wave. Learning objective: Ablation of the epicardial arrhythmogenic substrate in patients with early repolarization syndrome (ERS) has been shown to be effective, but the relationship between abnormal epicardial potentials and the pathophysiology is unclear. In this case, J-wave and epicardial delayed potentials were not considered to represent obvious arrhythmogenic substrates. Ablation of the triggered premature ventricular contraction may be effective in ERS without apparent abnormal potentials.

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.