Preoperative Prediction of Shock Impedance for Subcutaneous Implantable Cardioverter Defibrillator Using Chest Computed Tomography.

BACKGROUND: High shock impedance is associated with conversion failure among patients with subcutaneous implantable cardioverter defibrillators (S-ICD). Currently, there is no preoperative assessment method for predicting high shock impedance. This study examined the efficacy of chest computed tomography (CT) as a preoperative evaluation tool to assess the shock impedance of S-ICDs.Methods and Results: The amount of adipose tissue adjacent to the device and anteroposterior diameter at the basal heart region were measured preoperatively using chest CT. We examined the correlation between these measurements and shock impedance at the conversion test. We enrolled 43 patients with S-ICDs (mean [±SD] age 54±15 years; body mass index 23±4 kg/m2; PRAETORIAN score 30-270 points; amount of adipose tissue 1,250±716 cm3), who underwent intraoperative conversion tests by inducing ventricular fibrillation, which was terminated with a 65-J shock. A sufficient concordance correlation coefficient was observed between the shock impedance and the amount of adipose tissue (r=0.616, P<0.01) and anteroposterior diameter (r=0.645, P<0.01). In multiple regression analysis, the amount of adipose tissue (ß=0.439, P=0.009) and anteroposterior diameter (ß=0.344, P=0.038) were identified as independent predictive factors of shock impedance. CONCLUSIONS: The preoperative CT-measured amount of adipose tissue and basal heart anteroposterior diameter are independent predictors of shock impedance. These parameters may be more accurate in identifying higher shock impedance in patients with S-ICDs.

ST-Segment Elevation During Percutaneous Left Atrial Appendage Closure.

A 70-year-old patient with paroxysmal atrial fibrillation underwent left atrial appendage closure. The patient experienced transient hypotension during device implantation. The procedure was abandoned because of ST-T-wave changes on electrocardiography and elevated coronary flow velocity on transesophageal echocardiography, which indicated that the device caused coronary artery compression.

Impact of Renal Congestion in Patients With Secondary Mitral Regurgitation After Mitral Transcatheter Edge-to-Edge Repair.

BACKGROUND: Renal congestion is a potential prognostic factor in patients with heart failure and recently, assessment has become possible with intrarenal Doppler ultrasonography (IRD). The association between renal congestion assessed by IRD and outcomes after mitral transcatheter edge-to-edge repair (TEER) is unknown, so we aimed to clarify renal congestion and its prognostic implications in patients with mitral regurgitation (MR) who underwent TEER using MitraClip system.Methods and Results: Patients with secondary MR who underwent TEER and were assessed for intrarenal venous flow (IRVF) by IRD were classified according to their IRVF pattern as continuous or discontinuous. Of the 105 patients included, 78 patients (74%) formed the continuous group and 27 (26%) were the discontinuous group. Kaplan-Meier analysis revealed significant prognostic power of the IRVF pattern for predicting the composite outcome of all-cause death and heart failure rehospitalization (log-rank P=0.0257). On multivariate Cox regression analysis, the composite endpoint was independently associated with the discontinuous IRVF pattern (hazard ratio, 3.240; 95% confidence interval, 1.300-8.076; P=0.012) adjusted using inverse probability of treatment weighting. CONCLUSIONS: IRVF patterns strongly correlated with clinical outcomes without changes in renal function. Thus, they may be useful for risk stratification after mitral TEER for patients with secondary MR.

Changes in exercise stress echocardiographic parameters before and after transcatheter mitral valve edge-to-edge repair.

The safety and feasibility are still not well known for exercise-induced mitral regurgitation (MR). This study is aimed to assess and compare the hemodynamic and symptomatic changes in patients with significant secondary MR during exercise stress echocardiography (ESE) before and after transcatheter edge-to-edge repair (TEER). The study included a total of 15 patients with secondary MR who underwent ESE before and after TEER using the MitraClip system (Abbott, Abbott Park, IL, USA). Echocardiographic data of ESE were collected both before the procedure and during the follow-up visit at 3 months. During the one-year postoperative observation period, the rate of readmission due to heart failure was 13% (n = 2), with no recorded fatalities. Although no significant differences of ESE data were observed in exercise-induced pulmonary hypertension or cardiac output before and after the repair, the severity of MR was significantly improved after the procedure, both at rest (2 [2-3] vs. 1 [1-2], p = 0.0125) and during ESE (3 [3-3] vs. 1 [1-1], p < 0.0001). Furthermore, the New York Heart Association Functional Classification was improved (3 [3-3] vs. 1 [1-1], p < 0.0001) after treatment. For a supplemental analysis, MR during ESE was significantly improved not only in cases with atrial secondary MR but also in ventricular secondary MR. Transcatheter edge-to-edge repair for exercise-induced MR resulted in a significant improvement in postoperative MR severity and subjective symptoms. These results are novel, as they have not been extensively reported previously, particularly among Japanese patients.

Successful Epicardial Radiofrequency Ablation of Ventricular Tachycardia That Shared a Pathway with Bi-Directional Conduction in a Patient with Human Immunodeficiency Virus-Associated Cardiomyopathy.

A 59-year-old man who had been diagnosed with human immunodeficiency virus-associated cardiomyopathy was referred for catheter ablation of ventricular tachycardia (VT). An electrocardiogram (ECG) waveform revealed that the clinical VT originated from the epicardium. A deceleration zone (DZ) was identified on an isochronal late activation map. Moreover, 2 forms of monomorphic VT were induced by different cycle length burst pacings from near the DZ. The morphologies of the 2 VTs with an identical cycle length were very likely to use a shared common pathway with bi-directional conduction around the slow conduction area in the left ventricle posterolateral small epicardial surface area. After ablation of the DZ, the VT was uninducible.

Effects of temperature and humidity on cerebrovascular disease hospitalization in a super-aging society.

Weather conditions influence the incidence of cardiovascular disease. However, few studies have investigated the association between weather temperature and humidity and cerebrovascular disease hospitalizations in a super-aging society. We included 606,807 consecutive patients with cerebrovascular disease admitted to Japanese acute-care hospitals between 2015 and 2019. The primary outcome was the number of cerebrovascular disease hospitalizations per day. Multilevel mixed-effects linear regression models were used to estimate the association of mean temperature and humidity, 1 day before hospital admission, with cerebrovascular disease hospitalizations, after adjusting for air pollution, hospital, and patient demographics. Lower mean temperatures and humidity < 70% or humidity ≧ 70% are associated with an increased incidence of cerebrovascular disease hospitalization (coefficient, - 1.442 [- 1.473 to - 1.411] per °C, p < 0.001, coefficient, - 0.084 [- 0.112 to - 0.056] per%, p < 0.001, and coefficient, 0.136 [0.103 to 0.168] per %, p < 0.001, respectively). Lower mean temperatures and extremely lower or higher humidity are associated with an increased incidence of cerebrovascular disease hospitalization in a super-aging society.

Revisiting predictors of worse atrioventricular valve and left ventricular systolic function following pacemaker therapy.

BACKGROUND: Predictors of worsening atrioventricular valve regurgitation and left ventricular (LV) systolic function after implantation of a leadless pacemaker (LPM) remain unclear compared with those of a transvenous pacemaker (TPM). METHODS: We retrospectively analyzed 205 patients who were newly implanted with a permanent pacemaker (119 LPMs and 86 TPMs) and underwent transthoracic echocardiography before and 8 ± 5 months after implantation. We evaluated the worsening of tricuspid and mitral regurgitation (TR and MR), defined as at least one-grade aggravation in severity, and changes in LV ejection fraction (LVEF). RESULTS: Worsening TR occurred more frequently in the LPM group compared to the TPM group (33% vs. 20%, p = .04); however, there was no significant difference between the two groups regarding worsening MR (26% vs. 18%, p = .18) and LVEF change (-2 ± 10% vs. -3 ± 8%, p = .40). In multivariable analysis, independent predictors for worsening TR, MR, and LVEF after implantation were found to be (1) the change from sinus rhythm at baseline to atrioventricular asynchronous right ventricular (RV) pacing (odds ratio [OR]: 5.68, 95% confidence interval [CI]: 1.94-16.70, p < .01); (2) the change from non-pacing ventricular contraction at baseline to RV pacing (OR: 2.42, 95% CI: 1.12-5.24, p = .02); and (3) a higher RV pacing burden (ß: -0.05, 95% CI: -0.08--0.02, p < .01), respectively. CONCLUSION: Worsening TR, MR, and LVEF after pacemaker implantation were not associated with the type of pacing device but loss of atrioventricular synchrony or dependency on RV pacing.

Safety and Performance of the Micra VR Leadless Pacemaker in a Japanese Cohort　- Comparison With Global Studies.

BACKGROUND: The Micra leadless pacemaker has demonstrated favorable outcomes in global trials, but its real-world performance and safety in a Japan-specific population is unknown.Methods and Results: Micra Acute Performance (MAP) Japan enrolled 300 patients undergoing Micra VR leadless pacemaker implantation in 15 centers. The primary endpoint was the acute (30-day) major complication rate. The 30-day and 6-month major complication rates were compared to global Micra studies. All patients underwent successful implantation with an average follow-up of 7.23±2.83 months. Compared with previous Micra studies, Japanese patients were older, smaller, more frequently female, and had a higher pericardial effusion risk score. 11 acute major complications were reported in 10 patients for an acute complication rate of 3.33% (95% confidence interval: 1.61-6.04%), which was in line with global Micra trials. Pericardial effusion occurred in 4 patients (1.33%; 3 major, 1 minor). No procedure or device-related deaths occurred. Frailty significantly improved from baseline to follow-up as assessed by Japan Cardiovascular Health Study criteria. CONCLUSIONS: In a Japanese cohort, implantation of the Micra leadless pacemaker had a high success rate and low major complication rate. Despite the Japan cohort being older, smaller, and at higher risk, the safety and performance was in line with global Micra trials.

Two-year Outcomes of Ventricular-demand Leadless Pacemaker Therapy for Heart Block After Transcatheter Aortic Valve Replacement.

Ventricular-demand leadless pacemakers (VVI-LPMs) have often been used as an alternative to atrioventricular (AV) synchronous transvenous pacemakers (DDD-TPMs) in patients with high-grade AV block following transcatheter aortic valve replacement (TAVR). However, the clinical outcomes of this unusual usage are not elucidated. Patients who received permanent pacemakers (PPMs) owing to new-onset high-grade AV block after TAVR from September 2017 to August 2020 at a high-volume center in Japan were included in the analysis, and the clinical courses of VVI-LPM and DDD-TPM implants through 2 years of follow-up were compared retrospectively. Out of 413 consecutive patients who underwent TAVR, 51 (12%) patients received a PPM. After excluding 8 patients with chronic atrial fibrillation (AF), 3 with sick sinus syndrome, and 1 with incomplete data, 17 VVI-LPMs and 22 DDD-TPMs were included in our final cohort. The VVI-LPM group had lower serum albumin levels (3.2 ± 0.5 vs. 3.9 ± 0.4 g/dL, P < .01) than the DDD-TPM group. Follow-up revealed no significant differences between the 2 groups in terms of the incidence of late device-related adverse events (0% vs. 5%, log-rank P = .38) and new-onset AF (6% vs. 9%, log-rank P = .75); however, there were increases in the rates of all-cause death (41% vs. 5%, log-rank P < .01) and heart failure rehospitalization (24% vs. 0%, log-rank P = .01) in the VVI-LPM group. This small retrospective study reveals favorable post-procedural complication rates but higher all-cause mortality with VVI-LPM compared to DDD-TPM therapy for high-grade AV block after TAVR at 2 years of follow-up.

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.

Swallowing-induced Atrial Tachycardia with a Thymic Cyst.

We herein report a 34-year-old man who presented with recurrent palpitations that occurred while swallowing solid food. Holter monitoring revealed atrial tachycardia (AT) while eating. In addition, chest computed tomography (CT) showed a small nodule in the front of the ascending aorta. Thoracoscopic surgery was performed to remove the nodule; a pathological examination revealed that the nodule was a thymic cyst. The AT disappeared postoperatively. This case demonstrates that a mediastinal nodule can cause swallowing-induced AT.

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.

Speech-induced Atrial Tachycardia with Presyncope.

Speech-induced atrial tachycardia (AT) with presyncope is extremely rare. A 52-year-old woman employed at a supermarket reported recurrent presyncope while speaking out loud at her job. Holter electrocardiography revealed AT while swallowing without presyncope. The patient's blood pressure decreased during AT, and she experienced presyncope while saying "IRASSHAIMASE" loudly during a tilt table test. Accordingly, bisoprolol 1.25 mg was prescribed, and the patient did not experience episodes of presyncope with recurrence of AT for 2 years. This case suggests that provocation of arrhythmia in the tilting position may be useful for demonstrating a relationship between arrhythmia and presyncope and/or syncope.

Noteworthy sequelae after COVID-19 pneumonia in a patient with heart failure due to cardiomyopathy.

Coronavirus disease 2019 (COVID-19) is endemic worldwide. Cardiovascular disease, particularly myocarditis, is one of the most common comorbidities in patients with COVID-19. However, heart failure due to COVID-19-triggered cardiomyopathy is not well understood. Additionally, "pseudo" heart failure symptoms have been reported in patients with a compensated condition, in which the heart works well enough that symptoms are unnoticeable or very easy to manage. Here, we report a case of heart failure due to cardiomyopathy in a patient with COVID-19 and postural orthostatic tachycardia syndrome after heart failure treatment. Learning objective: Postural orthostatic tachycardia syndrome (POTS) symptoms after coronavirus disease 2019 may be mistaken for heart failure symptoms; thus, it is essential to suspect POTS when symptoms such as shortness of breath and palpitations are noted upon standing, along with the relevant physical findings.

Clinical Outcomes of Non-Atrial Fibrillation Bradyarrhythmias Treated With a Ventricular Demand Leadless Pacemaker Compared With an Atrioventricular Synchronous Transvenous Pacemaker　- A Propensity Score-Matched Analysis.

BACKGROUND: Implanting a ventricular demand leadless pacemaker (VVI-LPM) for patients with non-atrial fibrillation (AF) bradyarrhythmias such as sick sinus syndrome (SSS) or high-grade (i.e., second- or third-degree) atrioventricular (AV) block is not recommended unless they have limited vascular access or a high infection risk; nevertheless, an unexpectedly high number of VVI-LPM implantations have been performed. This study investigated the clinical outcomes of these unusual uses.Methods and Results:This study retrospectively analyzed 193 patients who were newly implanted with a VVI-LPM or an atrioventricular synchronous transvenous pacemaker (DDD-TPM) for non-AF bradyarrhythmias at a high-volume center in Japan from September 2017 to September 2020. Propensity score-matching produced 2 comparable cohorts treated with a VVI-LPM or DDD-TPM (n=58 each). Each group had 20 (34%) patients with SSS and 38 (66%) patients with high-grade AV block. During a median follow up of 733 (interquartile range 395-997) days, there were no significant differences between the VVI-LPM and DDD-TPM groups regarding late device-related adverse events (0% vs. 4%, log-rank P=0.155), but the VVI-LPM group had a significantly increased readmission rate for heart failure (HF) (29% vs. 2%, log-rank P=0.001) and a tendency to have higher all-cause mortality (28% vs. 4%, log-rank P=0.059). CONCLUSIONS: The implantation of a VVI-LPM for non-AF bradyarrhythmias increased the incidence of HF-related rehospitalization at the mid-term follow up compared to the use of a DDD-TPM.

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.