Comparative Data of Procedural and Midterm Outcomes in Patients Who Underwent Percutaneous Left Atrial Appendage Closure Between the WATCHMAN FLX and WATCHMAN 2.5 Devices　- Insight From the OCEAN-LAAC Registry.

BACKGROUND: Limited data are available regarding clinical outcomes after percutaneous left atrial appendage closure using WATCHMAN FLX (WM-FLX) and WATCHMAN-2.5 (WM2.5) devices in Asian patients.Methods and Results: Data of 1,464 consecutive patients (WM-FLX, n=909; WM2.5, n=555) were extracted from a Japanese multicenter registry, and clinical data were compared between the 2 groups. No in-hospital deaths, periprocedural stroke, or device embolization occurred. Procedural success was significantly higher in the WM-FLX than WM2.5 group (95.8% vs. 91.9%; P=0.002) owing to the lower incidence of periprocedural pericardial effusion (0.55% vs. 1.8%; P=0.021). No significant differences in all-cause death, postprocedural stroke, and device-related thrombus were observed between the 2 groups. However, the cumulative bleeding rate at 1 year was substantially lower in the WM-FLX group (7.8% vs. 16.4%; P<0.001). Landmark analysis of bleeding events highlighted lower bleeding rates in the WM-FLX than WM2.5 group within the first 6 months (6.4% vs. 14.8%; P<0.001), with comparable bleeding rates over the 6- to 12-month period (1.5% vs. 3.2%, respectively; P=0.065). CONCLUSIONS: This study demonstrated higher early safety and lower 1-year bleeding rates in the WM-FLX than WM2.5 group. The lower bleeding events with WM-FLX are likely due to multiple factors other than purely difference in devices, such as postprocedural drug regimen.

Posterior wall thickness of the confluent inferior pulmonary veins measured by left atrial intracardiac echocardiography: implications for catheter ablation.

BACKGROUND: Confluent inferior pulmonary veins (CIPV) is a rare anatomical variant. There is few evidence in the literature regarding anatomic landmarks consideration to guide radiofrequency application in avoiding complications in the esophagus in CIPV cases. METHODS: Of 986 consecutive patients undergoing atrial fibrillation (AF) ablation from July 2020 to June 2022, seven (0.7%) had CIPV with a common trunk connecting to the LA diagnosed by 3-dimensional contrast-enhanced computed tomography. Using intracardiac echocardiography (ICE) performed from the left atrium (LA), we measured the posterior wall thickness (PWT) of the CIPV adjacent to the esophagus and compared the measurement with the LA posterior wall thickness (LAPWT) at the left inferior PV level of 25 controls without CIPV. For ablation in CIPV patients, each superior PV was individually isolated, and box isolation of CIPV without ablating the CIPV posterior wall was added (tri-circle ablation technique). RESULTS: The CIPV PWT was 0.7 ± 0.1 mm, while non-CIPV LAPWT was 2.0 ± 0.4 mm (P < 0.001). In the CIPV group, upper and lower portions of the CIPV were both apart from the esophagus (mean distances, 6.7 ± 3.4 mm and 7.9 ± 2.7 mm, respectively). Individual superior PV isolation and box CIPV isolation resulted in complete isolation of all PVs, with no complications. All CIPV patients except one remained AF recurrence-free for 376 ± 52 days. CONCLUSIONS: Although CIPV frequency is low, CIPV PWT is very thin and special care is needed during ablation. A "tri-circle" ablation strategy avoids ablating in the thinnest portion of the posterior wall. Further studies are warranted to assess the safety.

Predictors of pulmonary vein non-reconnection in the second procedure after ablation index-guided pulmonary vein isolation for atrial fibrillation and its impact on the outcome.

INTRODUCTION: Although first-pass isolation (FPI) of the pulmonary vein (PV) has been suggested as a marker for PV isolation (PVI) durability, it has not been confirmed. Non-PV atrial fibrillation (AF) triggers were the main target in patients without PV reconnection in the second ablation procedure, but the outcome was unclear. We aimed to validate FPI as a marker of PVI durability and evaluate the outcome after the second procedure in patients without PV reconnection by comparing it to those with reconnection. METHODS: Among the 2087 patients undergoing the first ablation index-guided radiofrequency AF ablation, 309 with atrial tachyarrhythmias (ATs) recurrence and undergoing the second procedure were studied. Clinical characteristics and outcomes were compared between the patients without PV reconnection (PV non-reconnection group, n = 142) and with reconnection (PV reconnection group, n = 167). RESULTS: FPI in both PV sides in the first ablation procedure was significantly more frequent in the PV non-reconnection group (77.5%) than in the PV reconnection group (45.5%) (p < .001). Multivariate logistic regression analysis revealed that FPI (odds ratio, 3.71 [95% confidence interval, 2.23-6.19], p < .001) was the only predictor of PV non-reconnection. Radiofrequency applications for non-PV AF triggers were more frequently performed in the PV non-reconnection group (40.8% vs. 24.6%, respectively, p < .001). Kaplan-Meier analysis revealed that AT recurrence-free rate was significantly lower in the PV non-reconnection group (1-year recurrence-free rate, 62.7% vs. 75.4%, respectively; p = .01 by log-rank test). CONCLUSION: FPI was the only independent predictor of PV non-reconnection. Despite aggressive ablation for non-PV triggers, AT recurrence was more frequent in patients with PV non-reconnection.

Initial Japanese Multicenter Experience and Age-Related Outcomes Following Left Atrial Appendage Closure: The OCEAN-LAAC Registry.

Background: Limited data are available describing left atrial appendage closure (LAAC) and age-related outcomes in Asians. Objectives: This study summarizes the initial experience with LAAC in Japan and determines age-related clinical outcomes in patients with nonvalvular atrial fibrillation undergoing percutaneous LAAC. Methods: In an ongoing, prospective, investigator-initiated, multicenter, observational registry of patients undergoing LAAC in Japan, we analyzed short-term clinical outcomes in patients with nonvalvular atrial fibrillation who underwent LAAC. Patients were classified into younger, middle-aged, and elderly groups (≤70, 70 to 80, and >80 years of age, respectively) to determine age-related outcomes. Results: Patients (n = 548; mean age, 76.4 ± 8.1 years; male, 70.3%) who underwent LAAC at 19 Japanese centers between September 2019 and June 2021 were enrolled in the study, including 104, 271, and 173 patients in the younger, middle-aged, and elderly groups, respectively. Participants had a high-risk of bleeding and thromboembolism with a mean CHADS2 score of 3.1 ± 1.3, a mean CHA2DS2-VASc score of 4.7 ± 1.5, and a mean HAS-BLED score of 3.2 ± 1.0. Device success rates were 96.5% and anticoagulants discontinuation at the 45-day follow-up was achieved in 89.9%. In-hospital outcomes were not significantly different, but major bleeding events during the 45-day follow-up were significantly higher in the elderly group compared to the other groups (younger vs middle-aged vs elderly, 1.0% vs 3.7% vs 6.9%, respectively; P = 0.047) despite the same postoperative drug regimens. Conclusions: The initial Japanese experience with LAAC demonstrated safety and efficacy; however, perioperative bleeding events were more common in the elderly and postoperative drug regimens must be tailored (OCEAN-LAAC [Optimized Catheter Valvular Intervention-Left Atrial Appendage Closure] registry; UMIN000038498).

Safety and efficacy of ablation index-guided atrial fibrillation ablation in octogenarians.

BACKGROUND: Limited data on the efficacy and safety of atrial fibrillation (AF) ablation using an ablation index (AI) for octogenarians is available. We aimed to compare the efficacy and safety of AI-guided AF ablation between AF patients aged ≥80 years (Group 1) and <80 (Group 2). HYPOTHESIS: We hypothesized that AI-guided AF ablation could complete the procedure with comparable efficiency and safety in patients aged ≥80 years and <80. METHODS: We retrospectively reviewed 2087 AF patients undergoing their first AI-guided AF ablation in our hospital. We compared the atrial tachyarrhythmia (AT) recurrence and procedure-related complication rate between Group 1 (n = 193) and Group 2 (n = 1894). RESULTS: The mean age was 83.0 (interquartile range [IQR] 81.0, 84.0) years in Group 1 and 67.0 (IQR 60.0, 72.0) in Group 2. AF type was significantly different between the two groups: Of Group 1 patients, 120 (62.2%) had paroxysmal AF, 61 (31.6%) persistent AF, and 12 (6.2%) long-standing persistent AF, while of Group 2 patients, 1016 (53.6%) paroxysmal AF, 582 (30.7%) persistent AF, and 296 (15.6%) long-standing persistent AF (p = .001). Unadjusted AT recurrence-free survival curves showed similar AT recurrence-free survival between the two groups (p = .67 by log-rank test). After the adjustment for AF type, the survival curve was similar between them (hazard ratio, 1.24; 95% CI [0.92-1.65]; p = .15, Group 1 vs. Group 2). The rate of procedure-related complications was similar between the two groups (3.1% vs. 3.0%, respectively, p = .83). CONCLUSION: Catheter ablation guided by AI achieved similar AT recurrence and complication rates between elderly AF patients aged ≥80 years and patients <80 years.

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.

Inappropriate sinus tachycardia-induced cardiomyopathy with severe functional mitral regurgitation and successful treatment with ivabradine.

Ivabradine increases stroke volume, but does not have a negative impact on blood pressure (BP). Thus, a patient with low BP can benefit from treatment with ivabradine. A 72-year-old Japanese woman with asthma and chronic bronchitis presented with dyspnea. Her heart rate (HR) was 126 beats per minute and an electrocardiogram showed sinus tachycardia. The chest X-ray showed cardiomegaly and pulmonary congestion. A transthoracic echocardiogram (TTE) showed reduced left ventricular ejection function (LVEF) and severe functional mitral regurgitation (MR). We diagnosed her with inappropriate sinus tachycardia (IST) and heart failure (HF) due to tachycardia-induced cardiomyopathy. After resolving the pulmonary congestion with diuretics, we administered a minimum dose of bisoprolol, which resulted in re-exacerbation of the HF. Because IST was persistent, we initiated treatment with ivabradine. As soon as ivabradine was started, the HR decreased, the BP gradually increased, and HF compensation was achieved. Bisoprolol was continued and losartan was started. In summary, we used ivabradine for a patient with tachycardia, low BP, a low LVEF, and severe MR. By optimizing the medical therapy, exercise tolerance improved and she was discharged. The serum brain natriuretic peptide was significantly reduced and TTE showed an improved LVEF and reduced MR. .

Real-time visualization of the esophagus and left atrial posterior wall by intra-left atrial echocardiography.

PURPOSE: Localization of the esophagus and the left atrium (LA) posterior wall thickness (LAPWT) should be taken into account when delivering radiofrequency energy. To validate the visualization of the esophagus and analyze LAPWT by ICE advanced into the LA in patients with atrial fibrillation (AF) undergoing ablation index (AI)-guided pulmonary vein (PV) isolation. METHODS: In 73 patients (mean age, 68 ± 12; paroxysmal AF in 45), a 3-dimensional (3D) esophagus image was created with CARTO SoundstarⓇ and its location was compared with contrast esophagography saved in Carto UNIVU™. LAPWT adjacent to the esophagus was measured at 4 levels: left superior PV (LSPV), intervenous carina (IC), left inferior PV (LIPV), and LIPV bottom. A target AI value was 260 (25 W power) on the esophagus demonstrated by ICE. RESULTS: All patients had the esophagus posterior to the left PV antrum. Creating a 3D esophagus and measurement of LAPWT with ICE was done without any complications. ICE esophagus image was completely overlapped with contrast esophagography. LAPWT (mm) was 2.8 (interquartile range, 2.5-3.2), 2.2 (1.9-2.5), 1.9 (1.8-2.1), and 2.1 (1.9-2.4) for LSPV, IC, LIPV, and LIPV bottom, respectively, while LA roof thickness was 3.2 (2.9-3.6) (P < 0.0001 by ANOVA). No residual conduction gap on the esophagus after the first circumferential PV isolation was found in 64 of 73 (88%) patients. CONCLUSIONS: ICE inserted into the LA can reliably locate and display the esophagus and its relationship to the LA. LAPWT was the thinnest at the LIPV level. AI-guided ablation targeting at AI value 260 on the esophagus seemed to be effective.

Ablation Index-Guided High-Power Radiofrequency Application Shortens the Procedure Time With Similar Outcomes to Conventional Power Application in Atrial Fibrillation Ablation.

Background: The impact of high-power radiofrequency (RF) application in ablation index (AI)-guided atrial fibrillation (AF) ablation has not been elucidated. Methods and Results: We investigated 1,333 patients undergoing first AF ablation (median age 68 years; interquartile range [IQR] 61-73 years). The first 301 patients underwent AI-guided conventional power RF application (CP group), whereas the following 1,032 patients underwent high-power RF application (HP group). The minimum AI target values were 400, 360, and 260 at the left atrial anterior wall, posterior wall, and esophagus, respectively. RF power in the CP group was 30-40, 20-25, and 20 W at the anterior wall, posterior wall, and esophagus, respectively, compared with 50, 40, and 25, respectively, in the HP group. Procedure time was shorter in the HP than CP group (median 153 [IQR 129-190] vs. 180 (IQR 152-229) min; P<0.0001). The percentage of first-pass pulmonary vein isolation (69% vs. 73%; P=0.07) and all procedure-related complications (2.0% vs. 3.4%; P=0.19) was similar. Kaplan-Meier analysis showed similar recurrence-free survival (RFS) for all AF types. Respective 1-year RFS in the CP and HP groups was 82% and 87% in paroxysmal AF, 78% and 82% in persistent AF, and 59% and 58% in long-standing persistent AF. Conclusions: In AI-guided AF ablation, high-power RF application shortens the procedure time without increasing complications and with similar outcomes.

High-power application is associated with shorter procedure time and higher rate of first-pass pulmonary vein isolation in ablation index-guided atrial fibrillation ablation.

BACKGROUNDS: Ablation index (AI) is useful to complete circumferential pulmonary vein isolation (CPVI) for atrial fibrillation (AF), but the role of radiofrequency power in AI-guided CPVI remains to be elucidated. METHODS: We investigated 60 patients with AF undergoing AI-guided CPVI (mean age, 66 ± 9 years; nonparoxysmal AF in 16). The first 40 patients were randomly assigned to low-power (LP; n = 20) and medium-power (MP; n = 20) groups and the following 20 patients to high-power (HP). In LP, radiofrequency (RF) application was done at 30 W at the anterior and 20 W at the posterior left atrial (LA) wall, while in MP, it was at 40 W at the anterior and 30 W at the posterior LA wall. In HP, 50 W was applied at the anterior, 40 W at posterior LA wall and 30 W on the esophagus. At each ablation point, target AI was 400 at the anterior, 360 at the posterior LA wall, and 260 on the esophagus. RESULTS: The time to complete both-side CPVI was shortest in HP (median, 40 minutes, interquartile range [IQR], 28-63) followed by MP (58 [49-83] minutes, P = .008 vs HP) and LP (84 [72-93] minutes, P = .002 vs MP). Higher RF power application significantly increased first-pass isolation rate (55% in LP, 80% in MP and 85% in HP, P = .002) and decreased LA-PV reconnection rate (10% in LP, 8% in MP, and 0% in HP, P = .03). CONCLUSION: In AI-guided PVI, the HP RF application can shorten the time to complete PVI with a high rate of first-pass isolation and a low rate of LA-PV reconnection.

Safety and Efficacy of Subcutaneous Cardioverter Defibrillator in Patients at High Risk of Sudden Cardiac Death　- Primary Japanese Experience.

BACKGROUND: The entirely subcutaneous implantable cardioverter defibrillator (S-ICD) was introduced as a new alternative to conventional transvenous ICD (TV-ICD) in Japan in February 2016, but its safety and efficacy are unclear.Methods and Results:A total of 60 patients (48 men, median age, 60 years; IQR, 44-67 years; primary prevention, n=24) underwent S-ICD implantation between February 2016 and August 2017. The device pocket was formed in the intermuscular space between the serratus anterior muscle and the latissimus dorsi muscle, and the parasternal S-ICD lead was placed according to pre-implant screening. Defibrillation test was performed in 56 patients (93%). Ventricular fibrillation (VF) was induced in 55 patients and terminated by a single 65-J shock in all patients. The median time to shock therapy was 13.4 s (IQR, 12.1-14.9 s) and the median post-shock impedance of the S-ICD lead was 64 Ω (IQR, 58-77 Ω). There were no operation-related complications or subsequent infectious complications. During follow-up (median, 275 days; IQR, 107-421 days), 1 patient (1.7%) had appropriate shock for VF with successful termination, whereas 5 patients (8.3%) had inappropriate shock due to oversensing of myopotential (n=3) or T-wave (n=1), and detection of supraventricular tachycardia (n=1). CONCLUSIONS: S-ICD is a safe and effective alternative to conventional TV-ICD. The long-term safety and efficacy of the S-ICD need further investigation.

Strategy and Outcome of Catheter Ablation for Persistent Atrial Fibrillation　- Impact of Progress in the Mapping and Ablation Technologies.

Pulmonary vein (PV) antrum isolation (PVAI) is effective in treating paroxysmal atrial fibrillation (AF) but is less so for persistent AF. A recent randomized study on the ablation strategies for persistent AF demonstrated that 2 common atrial substrate modifications, creation of linear lesions in the left atrium and ablation of complex fractionated electrogram sites, in addition to PVAI did not improve the outcome compared with stand-alone PVAI, suggesting the necessity of a more individualized, selective approach to persistent AF. There are emerging technologies, including high-resolution mapping with the use of multi-electrode catheter and auto mapping system and contact force (CF) guide ablation; the former allows rapid and accurate confirmation of the completeness of PVAI, and the latter enhances the achievement of durable ablation lesions more securely. Ablation for fibrotic area(s) has been proposed as a new approach for substrate modification, and high-resolution mapping is useful to define the area with low-voltage electrograms, a surrogate marker for atrial fibrosis. Ablation for non-PV triggers in addition to PVAI improves the outcome of persistent AF. Further, durable isolation of the left atrial posterior wall may reduce AF recurrence. These ablation strategies with concomitant use of the emerging technologies are strongly expected to enhance the effectiveness of catheter ablation for persistent AF.

Impact of left ventricular diastolic dysfunction on outcome of catheter ablation for atrial fibrillation in patients with hypertrophic cardiomyopathy.

BACKGROUND: The relationship between outcome of radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) and the severity of left ventricular (LV) diastolic dysfunction in patients with hypertrophic cardiomyopathy (HCM) remains unknown. METHODS AND RESULTS: Twenty-two HCM patients (12 female, aged 65 ± 11 years) with paroxysmal (n=5; 23%) or persistent (n=17; 77%) AF were enrolled. LV diastolic function was evaluated according to the ratio of the mitral inflow early filling velocity to the velocity of the early medial mitral annular ascent (E/e') measured on pulsed wave and tissue Doppler assessments in all patients. Pulmonary vein isolation was performed in all patients. A second procedure was performed in 3 patients. During a follow-up of 21 ± 12 months, sinus rhythm was maintained in 13 of 22 patients (59%). E/e' was significantly higher in the patients with AF recurrence than in those without (18 ± 7 vs. 11 ± 3; P<0.01). On Kaplan-Meier analysis the prevalence of AF recurrence was significantly higher in patients with E/e' ≥ 15 (n=6) than in those with E/e' <15 (n=16; P<0.01). On multivariate Cox regression analysis the only significant and independent predictor for AF recurrence was E/e' (hazard ratio, 1.16; 95% confidence interval: 1.01-1.37, P=0.03). CONCLUSIONS: LV diastolic dysfunction evaluated using E/e' was associated with difficulty of rhythm control after RFCA in patients with HCM and AF.

D-dimer is helpful for differentiating acute aortic dissection and acute pulmonary embolism from acute myocardial infarction.

INTRODUCTION: Acute aortic dissection (AAD), acute pulmonary embolism (PE) and acute myocardial infarction (AMI) are all emergent diseases with acute chest pain. However, it is sometimes difficult to diagnose these diseases by symptoms, ECG changes and/or cardiac biomarkers, especially immediately after onset. Because these diseases are all thrombogenic diseases, we considered that D-dimer could be helpful to differentiate these diseases. The purpose of this research was to define the D-dimer value for discrimination between AAD, PE and AMI. METHODS: Plasma D-dimer values of a consecutive series of 35 AAD, 22 PE and 206 AMI patients on admission were analyzed retrospectively. RESULTS: The D-dimer values of patients with AAD (32.9 ± 66.7 g/ml, p<0.001) and PE (28.5 ± 23.6 g/ ml, p<0.001) were significantly higher than those of AMI patients (2.1 ± 3.7 g/ml). A cutoff value of 5.0 g/ ml was effective in distinguishing AAD and PE from AMI, with a sensitivity of 68% and a specificity of 90%. CONCLUSIONS: Our study showed the possibility that D-dimer could enable faster diagnosis and treatment of AAD, PE and AMI patients. We expect that the D-dimer test will be used more often for screening patients with possible AAD, PE or AMI in the emergency room. We would recommend contrast computed tomography first, not coronary angiography, in a patient with a D-dimer level higher than 5.0 g/ml using our diagnostic kit.

A case of cardiac sarcoidosis masquerading as arrhythmogenic right ventricular cardiomyopathy awaiting heart transplant.

We report a case of 45-year-old man, who was diagnosed with arrhythmogenic right ventricular cardiomyopathy (ARVC) and presented with right ventricular (RV) enlargement with a global decrease in RV contractility accompanied by impairment of left ventricular function. He was placed on the heart transplant waiting list. Endomyocardial biopsy from RV septal wall did not show any evidence of sarcoidosis or inflammatory change. Four years after he was put on the heart transplant waiting list, a computed tomography chest scan for the purpose of anatomical evaluation for coronary sinus prior to biventricular pacing lead implantation incidentally showed bilateral hilar lymphadenopathy, which suggested the possibility of sarcoidosis. Biopsy of the inguinal lymph node pathologically was consistent with sarcoidosis. The 2[18F]fluoro-2-deoxy-d-glucose positron emission tomography scanning (FDG-PET) demonstrated intense uptake in the myocardium, and the patient was finally diagnosed as having cardiac sarcoidosis. After steroid treatment, the abnormal FDG-PET uptake disappeared. The patient therefore represented a case of cardiac sarcoidosis masquerading as ARVC. It should be recognized that RV involvement is one of the manifestations in cardiac sarcoidosis.