JCS/JHFS 2018 Guideline on the Diagnosis and Treatment of Cardiomyopathies

Phase 3 Open-Label Study Evaluating the Efficacy and Safety of Mavacamten in Japanese Adults With Obstructive Hypertrophic Cardiomyopathy - The HORIZON-HCM Study

BACKGROUND

Mavacamten, a cardiac myosin inhibitor, significantly improved symptoms and cardiac function vs. placebo in patients with symptomatic obstructive hypertrophic cardiomyopathy (HCM) in EXPLORER-HCM. However, the efficacy and safety profiles of mavacamten in Japanese patients are unclear.

METHODS AND RESULTS

HORIZON-HCM is a Phase 3 single-arm study in Japanese patients with symptomatic obstructive HCM. The mavacamten starting dose was 2.5 mg; individualized dose titration occurred in Weeks 6-20 based on Valsalva left ventricular outflow tract (LVOT) gradient and resting left ventricular ejection fraction (LVEF). Overall, 38 patients were treated; 36 completed the 30-week primary treatment analysis period. Clinically significant improvements in postexercise LVOT gradient were observed after 30 weeks of treatment (mean change from baseline -60.7 mmHg). Improvements in N-terminal pro B-type natriuretic peptide, New York Heart Association class, and Kansas City Cardiomyopathy Questionnaire-23 Clinical Summary Score were observed over 30 weeks, and mean LVEF was ≥74% at all visits. Treatment-emergent adverse events (TEAEs) and serious TEAEs were reported in 63.2% and 7.9% of patients, respectively; none resulted in treatment discontinuation. One patient experienced a transient asymptomatic reduction in LVEF to <50%. No deaths occurred during the study.

CONCLUSIONS

In Japanese patients with obstructive HCM, mavacamten was associated with similar improvements in LVOT gradients, cardiac biomarkers, and symptoms to those observed in EXPLORER-HCM. Treatment was well tolerated with no new safety concerns.

Mitochondrial Structural Abnormalities and Cardiac Reverse Remodeling in Patients With Systolic Dysfunction

BACKGROUND

Mitochondrial dysfunction in the heart is associated with the development of heart failure (HF). However, the clinical consequences of mitochondrial structural abnormalities in patients with HF remain unexplored.

METHODS AND RESULTS

Ninety-one patients with left ventricular (LV) systolic dysfunction who underwent endomyocardial biopsy (EMB) were enrolled in the study. Myocardial specimens were obtained from the right ventricular septum. Specimens were characterized using electron microscopy to assess mitochondrial size, outer membrane disruption, and cristae disorganization. The primary endpoint was a composite of cardiovascular death and unplanned hospitalization for HF. Patients were classified into LV reverse remodeling (LVRR)-positive (n=52; 57.1%) and LVRR-negative (n=39; 42.9%) groups. Cristae disorganization was observed in 21 (23.1%) patients: 6 (11.5%) in the LVRR-positive group and 15 (38.5%) in the LVRR-negative group (P=0.005). During the 1-year post-EMB observation period, 16 patients (17.6%) met the primary endpoint, with 2 (2.2%) cardiovascular deaths and 14 (15.4%) HF hospitalizations. Cristae disorganization (P=0.002) was significantly associated with the endpoints, independent of age (P=0.115), systolic blood pressure (P=0.004), B-type natriuretic peptide level (P=0.042), and mitral regurgitation (P=0.003).

CONCLUSIONS

We classified mitochondrial structural abnormalities and showed that cristae disorganization was associated with LVRR and worse prognosis. These findings may affect the management of patients with HF and systolic dysfunction who undergo EMB.

Long-term clinical outcomes after alcohol septal ablation for hypertrophic obstructive cardiomyopathy in Japan: a retrospective study

Hypertrophic cardiomyopathy is characterized by significant left ventricular wall thickening, often leading to obstructive symptoms. Alcohol septal ablation (ASA) has emerged as an effective treatment for patients with hypertrophic obstructive cardiomyopathy (HOCM) who remain symptomatic despite maximal medical therapy. However, the detailed long-term effects of ASA in Japanese patients with HOCM remain unclear. Therefore, this study aimed to investigate the long-term effects of ASA for HOCM by evaluating changes in symptoms, pressure gradient, hemodynamics, prognosis, and predictive factors for cardiovascular events over time. In this retrospective study, we examined 239 highly symptomatic patients (age, 64 ± 13 years; median follow-up, 6.9 years) treated with ASA for drug-refractory HOCM between 1998 and 2021. Patients were assessed using transthoracic echocardiography, magnetic resonance imaging, and cardiac catheterization. Follow-up evaluations included clinical assessments, electrocardiography, and echocardiography. Data analysis included descriptive statistics, Kaplan-Meier analysis, and multivariate regression. ASA reduced the left ventricular outflow tract gradient from 90.5 ± 52.8 to 14.4 ± 17.1 mmHg (P < 0.01) and New York Heart Association (NYHA) class from 3 [2.5-3] to 1 [1-2] at 10 years after ASA (P < 0.01). The 30-day mortality rate following ASA was 1%. Overall, 31 patients (13%) died during the follow-up period. The survival rates at 1, 5, 10, and 15 years after ASA were 97.4%, 89.9%, 83.7%, and 77.6%, respectively. Multivariable analysis revealed NYHA functional class before ASA (odds ratio [OR], 3.09; 95% confidence interval [CI], 1.40-6.82; P = 0.005), beta-blocker use (OR, 0.25; 95% CI, 0.07-0.91; P = 0.036), and class Ia agent use (OR, 0.31; 95% CI, 0.13-0.75; P = 0.009) as independent predictors of all-cause mortality. This study demonstrated low periprocedural and long-term mortality rates following ASA in patients with HOCM, suggesting that ASA provides durable symptomatic relief and reduces left ventricular outflow tract obstruction in selected highly symptomatic patients with HOCM.

Canadian Association of Radiologists Cardiovascular Imaging Referral Guideline

The Canadian Association of Radiologists (CAR) Cardiovascular Expert Panel is made up of physicians from the disciplines of radiology, cardiology, and emergency medicine, a patient advisor, and an epidemiologist/guideline methodologist. After developing a list of 30 clinical/diagnostic scenarios, a rapid scoping review was undertaken to identify systematically produced referral guidelines that provide recommendations for one or more of these clinical/diagnostic scenarios. Recommendations from 48 guidelines and contextualization criteria in the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) for guidelines framework were used to develop 125 recommendation statements across the 30 scenarios (27 unique scenarios as 2 scenarios point to the CAR Thoracic Diagnostic Imaging Referral Guideline and the acute pericarditis subscenario is included under 2 main scenarios). This guideline presents the methods of development and the referral recommendations for acute chest pain syndromes, chronic chest pain, cardiovascular screening and risk stratification, pericardial syndromes, intracardiac/pericardial mass, suspected valvular disease cardiomyopathy, aorta, venous thrombosis, and peripheral vascular disease.

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

BACKGROUND

Pulmonary vein isolation (PVI) employing cryoballoon (CB) or contact force-guided radiofrequency (CF-RF) catheter ablation has been established as an effective strategy for managing atrial fibrillation (AF). However, its efficacy in hypertrophic cardiomyopathy (HCM) remains to be further explored.

METHODS

This retrospective study analyzed 60 consecutive AF patients with HCM (average age 67 ± 10 years; 41 men) who were consecutively admitted to our hospital from January 2014 to December 2022 and underwent initial PVI.

RESULTS

The patients were treated with CB (26 patients) or CF-RF (34 patients). Successful PVI was achieved in both groups without significant complications. In the CF-RF group, additional ablations were performed on the cavotricuspid isthmus (14.7% of patients) and the anterior line (2.9%). The CB group benefited from reduced procedural times (93 ± 31 vs. 165 ± 60 min, p < 0.05) and decreased saline irrigation requirements (77.5 ± 31.4 vs. 870 ± 281.9 mL, p < 0.0001). Using a contrast medium was exclusive to the CB group (33.8 ± 4.2 mL). In a 12-month follow-up, the atrial tachyarrhythmia recurrence-free rates in the CB and CF-RF groups were comparable (77% and 76%, respectively; p = 0.63 according to the log-rank test). Notably, pulmonary vein reconnection was prevalent in most (7 out of 8) patients requiring a secondary ablation procedure.

CONCLUSION

PVI is feasible as a strategy for AF in patients with HCM employing either CB or CF-RF techniques. While the recurrence-free rates were comparable in both groups, differences were noted in procedure duration, saline usage, and the need for a contrast medium.

Cardiomyopathy with an LMNA Genetic Variant Affecting Three Consecutive Generations: A Case Series

We report the case of a family afflicted with cardiac laminopathy who showed atrial fibrillation (AF) and complete atrioventricular block across three generations. Implantable cardioverter defibrillators (ICDs) implantation, or cardiac resynchronization therapy (CRT) were delivered to the three patients (proband; 61 years old, proband's mother: 84 years old, and proband's daughter; 38 years old) to prevent sudden cardiac death or suppress heart failure progression. A novel frameshift mutation (LMNA Exon 9: c.1550dupA;p. N518Efs*34) was found in all three cases through genetic testing, and this mutation may potentially result in the relatively late appearance of a phenotype of left ventricular systolic dysfunction.

Usefulness of exercise stress echocardiography for predicting cardiovascular events and atrial fibrillation in hypertrophic cardiomyopathy

BACKGROUND

In hypertrophic cardiomyopathy (HCM), the determinants of exercise tolerance and the usefulness of exercise stress echocardiography (ESE) for predicting hard endpoints have not been fully investigated. We aimed to assess the key parameters of ESE for exercise tolerance and the factors predictive of cardiovascular events and new-onset atrial fibrillation (AF) in patients with HCM.

METHODS

Seventy-four consecutive patients with HCM who underwent ESE and with an ejection fraction ≥50 % were enrolled. The primary endpoint was a composite of cardiovascular death, heart failure hospitalization, ventricular fibrillation or tachycardia, and ventricular assist device implantation. The secondary endpoint was new-onset AF.

RESULTS

The primary endpoint occurred in 13 patients. The left and right ventricular functions during exercise were responsible for decreased exercise tolerance. Peak exercise e' and tricuspid annular plane systolic excursion (TAPSE) significantly predicted increased primary outcome risk (hazard ratio 1.35, 95 % confidence interval 1.10-1.76, p = 0.003; hazard ratio 1.19, 95 % confidence interval 1.07-1.32, p = 0.002, respectively), and the results were consistent even after adjustment by maximum workload. These ESE parameters improved the prognostic model containing estimated glomerular filtration rate (eGFR) and left atrial (LA) volume index. In AF-naive patients (n = 58), LA volume, peak exercise LA reservoir strain, and left ventricular outflow tract (LVOT) pressure gradient predicted new-onset AF.

CONCLUSIONS

In patients with HCM, ESE parameters related to left and right ventricular function were responsible for low exercise tolerance. Furthermore, e' and TAPSE at peak workload could be useful for predicting cardiovascular events in addition to eGFR and LA volume index. LVOT pressure gradient and LA function during exercise predicted new-onset AF.

An evidence review and gap analysis for obstructive hypertrophic cardiomyopathy

BACKGROUND

Patients with obstructive hypertrophic cardiomyopathy (oHCM) have a substantial humanistic, clinical, and economic burden due to the array of symptoms and complications associated with the disease. The objective of this review was to identify key evidence gaps related to oHCM, specifically in Europe, North America, and Japan.

METHODS

A targeted literature review was conducted using PubMed to identify English-language studies published between 2012 and 2022 assessing patients with HCM/oHCM in France, Germany, Italy, Spain, the United Kingdom (UK), the United States (US), Canada, and Japan. Outcomes of interest were epidemiology, natural history, pathophysiology, management, and clinical, economic, and humanistic burden. Identified studies were assessed qualitatively to characterize evidence gaps.

RESULTS

Among 2,262 abstracts and 531 full-text articles screened, 178 articles were included from PubMed searches. An additional 16 unique studies were identified via a supplemental Google Scholar search initially conducted in January 2023 and updated in July 2024. Disease natural history, pathophysiology, and management were well documented globally. Significant evidence gaps were noted for the epidemiology, treatment, and burden of oHCM. Although multiple US studies were identified on the clinical, economic, and humanistic burden of oHCM, and one clinical burden study was found for Japan, there was a lack of evidence for France, Germany, Italy, Spain, the UK, and Canada.

CONCLUSIONS

Major evidentiary gaps exist for the epidemiology, treatment, and burden of oHCM. Future research should address these gaps, with a specific focus on generating real-world evidence for Canada and European countries that will support the evaluation of emerging therapies in these regions.

Genetic testing and human leukocyte antigen in patients with hypertrophic cardiomyopathy and connective tissue diseases

Hypertrophic cardiomyopathy (HCM) is caused by myocardial hypertrophy, often due to mutations in cardiac sarcomere protein genes such as beta-myosin heavy chain (MYH7) and myosin-binding protein C (MYBPC3). However, a significant proportion of HCM cases lack identified genetic mutations, and genotype-phenotype correlations remain unclear. Concurrently, potential associations between HCM and human leukocyte antigen (HLA) types, as well as connective tissue diseases, have been proposed. In this single-center study, we aimed to investigate the genetic and HLA profiles of patients with obstructive hypertrophic cardiomyopathy (HOCM) and connective tissue diseases, particularly focusing on the prevalence of genetic variants and HLA types. We conducted a detailed analysis of five patients with HOCM and connective tissue diseases and sarcoidosis, identifying rare variants in causative genes for HCM in two cases and observing specific HLA types that were relatively common. Notably, 15% of all HOCM cases presented with connective tissue diseases, mainly rheumatoid arthritis. These findings underscore the complexity of HCM etiology and suggest potential implications for both diagnostic strategies and therapeutic approaches in patients with concomitant inflammatory conditions.

Usefulness of platelet count to predict concomitant valvular heart disease in patients with systemic lupus erythematosus

Background

Although the prevalence rate of valvular heart disease (VHD) is high in patients with systemic lupus erythematosus (SLE), the predictive factors of concomitant VHD have not been fully evaluated.

Methods and results

Among 288 patients with SLE who underwent transthoracic echocardiography at Kumamoto University Hospital from 2016 to 2021, 241 patients with sufficient echocardiographic data were retrospectively analysed. Among them, 22 (9 %) had VHD (10 had mitral regurgitation, 3 had aortic regurgitation, 6 had tricuspid regurgitation, 1 had mitral regurgitation and tricuspid regurgitation, and 2 had a prosthetic cardiac valve). After excluding the two patients with a prosthetic cardiac valve, we divided the remaining patients into two groups: the VHD group and non-VHD group. Multivariate logistic regression analysis revealed that age and the platelet count were significantly and independently associated with having VHD (age: odds ratio, 1.06; 95 % confidence interval, 1.02-1.10; p < 0.01) (platelet count: odds ratio, 0.99; 95 % confidence interval, 0.98-1.00; p < 0.05). After excluding 95 patients aged < 40 years, receiver operating characteristic analysis revealed that the area under the curve of the platelet count for prediction of VHD was 0.73 with an optimal cut-off value of 166.5 × 103/µL (sensitivity: 76.6 %, specificity: 60.0 %). Among patients with a low platelet count (<166.5 × 103/µL), the rate of having VHD was 29 % (12/41 patients). However, among those with a high platelet count (≥166.5 × 103/µL), this rate was only 8 % (8/103 patients).

Conclusion

The platelet count is useful to predict concomitant VHD in middle-aged and older patients with SLE.

Associations between electrocardiographic findings and echocardiographic profiles in patients with hypertrophic cardiomyopathy

BACKGROUND

The relationships between electrocardiography (ECG) findings and echocardiographic profiles in patients with hypertrophic cardiomyopathy (HCM) are not fully understood.

METHODS

One hundred forty patients (mean age: 62.9 ± 15.3 years, 96 men) with HCM were studied. We assessed the associations between ECG findings and echocardiographic findings including maximum left ventricular wall thickness, HCM subtypes and distribution of left ventricular hypertrophy (LVH): the LV was divided into basal, mid, and apical segments by dividing it into thirds along the long axis.

RESULTS

In ECG, LVH by voltage criteria, abnormal Q wave, negative T wave, and giant negative T wave (GNT) were observed in 74 (53 %), 30 (21 %), 132 (94 %), and 25 (18 %) of the patients, respectively. In two groups with and without an LVH pattern according to voltage criteria in ECG, there were no significant differences in maximum LV wall thickness, subtype of HCM, and distribution of LVH. Regarding an abnormal Q wave, the proportion of patients with LVH in the basal segment was significantly higher in patients with an abnormal Q wave than in patients without an abnormal Q wave (87 % vs 61 %, p = 0.008). An abnormal Q wave was not observed in patients with LVH confined to the apex. Patients with a GNT included patients with LVH located at only the apex (apical HCM), LVH from the mid segment to apex, and LVH from the base to apex. No GNT was found in patients with hypertrophy located in the upper region from the base to mid segment of the LV.

CONCLUSIONS

In patients with HCM, there was no significant correlation between the presence of LVH by voltage criteria in ECG and echocardiographic findings. An abnormal Q wave was associated with disproportionate hypertrophy of the basal wall and a GNT reflected the presence of LVH in the apical segment.

Sitting maneuver to uncover latent left ventricular outflow tract obstruction in patients without hypertrophic cardiomyopathy

BACKGROUND

Left ventricular outflow tract obstruction [LVOTO; pressure gradient (PG) ≥30 mmHg] is observed in some patients without hypertrophic cardiomyopathy (HCM), and it may develop especially in older patients without HCM (non-HCM). The aim of this study is to investigate if the Valsalva or an upright sitting maneuver can unveil latent LVOTO in patients with non-HCM.

METHODS

A total of 33 non-HCM patients with a late peaking or dagger-shaped pulsed Doppler waveform of the LVOT and PG <30 mmHg were included. The Doppler flow velocity of the LVOT was measured at rest, after the Valsalva and a sitting maneuver. Peak PG of ≥30 mmHg after either maneuver was defined as latent LVOTO. The angle between the left ventricular septum and the aorta in the parasternal long-axis view and the apical three-chamber view was measured.

RESULTS

Twenty (61 %) of the 33 patients (mean age 74 ± 9 years) were diagnosed with latent LVOTO. Of these, five (25 %) patients were diagnosed after both the Valsalva and sitting maneuver, and 15 (75 %) were diagnosed only after the sitting maneuver. The latent LVOTO group had a significantly smaller angle than the no-LVOTO group between the ventricular septum and the aorta in the parasternal long axis views (107 ± 8° vs. 117 ± 8°, p < 0.01).

CONCLUSION

The sitting maneuver is better than the Valsalva maneuver in unveiling latent LVOTO in older, non-HCM patients.

Management of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy is an important cause of heart failure and arrhythmias, including sudden death, with a major impact on the healthcare system. Genetic causes and different phenotypes are now increasingly being identified for this condition. In addition, specific medications, such as myosin inhibitors, have been recently shown as potentially able to modify its symptoms, hemodynamic abnormalities and clinical course. Our article aims to provide a comprehensive outline of the epidemiology, diagnosis and treatment of hypertrophic cardiomyopathy in the current era.

A Case of New-Onset Atrial Tachyarrhythmias With Apical Hypertrophic Cardiomyopathy and Bronchiectasis in a Very Elderly Patient: A Therapeutic Dilemma

Hypertrophic cardiomyopathy (HCM) is a primary myocardial disease that is genetically transmitted as an autosomal dominant trait. Even apical HCM (ApHCM) induces atrial fibrillation (AF) based on underlying left ventricle (LV) diastolic dysfunction, where anticoagulation therapy is recommended. However, anticoagulation for AF in patients at high risk of bleeding is a double-edged sword. A 98-year-old woman living in a nursing home presented to our hospital with sudden-onset dyspnea and palpitation persisting for two hours. The patient had a history of apical HCM and bronchiectasis. An electrocardiogram showed a regular tachycardia with a heart rate of 130 bpm, suggesting atrial flutter with 2:1 atrioventricular conduction. Intravenous verapamil (5 mg) resulted in the conversion into AF, and subsequent cibenzoline (70 mg) failed to restore sinus rhythm. Given the impossibility of continuous anticoagulation, electrical cardioversion was planned. Electrical cardioversion was successful in converting AF into sinus rhythm. Given the very high risk of hemoptysis, anticoagulation was avoided. This case gives an insight into how to manage a practical therapeutic problem, which is the coexistence of AF and bronchiectasis. A variety of individual factors should be considered for clinical decision-making and management of patients with concomitant HCM and AF.

Serum brain natriuretic peptide levels may be a useful marker for early diagnosis of cardiomyopathy secondary to neuroblastoma: A case report

Cardiomyopathy is a rare but serious complication associated with neuroblastoma. The brain natriuretic peptide level led to a diagnosis of secondary dilated cardiomyopathy before the worsening of heart failure symptoms.

Treatment with catheter ablation for patients with arrhythmia-induced cardiomyopathy caused by atrial fibrillation promises a good prognosis

Clinical outcomes after catheter ablation in patients with reduced left ventricular (LV) ejection fraction (EF) and atrial fibrillation (AF) remain unclear. This study aimed to explore the clinical outcomes of patients with arrhythmia-induced cardiomyopathy (AIC) and the influence of pharmacological treatment on clinical outcomes in patients with AIC after the procedure. Ninety-six patients with AF with a reduced LVEF (LVEF < 50%, 66.7 ± 10.9 years; 72 males) underwent AF ablation. AIC was defined as patients whose LVEF recovered ≥ 50% after catheter ablation (n = 67) and patients whose LVEF remained reduced were defined as non-AIC (n = 29). During a median follow-up of 25 (13-40) months, Kaplan-Meier analysis demonstrated that patients with AIC were associated with less frequent cardiovascular death (p = 0.025) and hospitalization for worsening heart failure (p < 0.001) than those without AIC. Freedom from AF recurrence was similar between the two groups (p = 0.47). In multivariate analysis, the LV end-diastolic diameter (p = 0.0002) and the CHA2DS2-VASc scores (p = 0.0062) were independent predictors of AIC. Among the 67 patients with AIC, no significant differences in baseline characteristics, except for LV chamber size and cryoballoon use, were observed between patients with AIC with (n = 31) and without renin-angiotensin system (RAS) inhibitors (n = 36). In the Kaplan-Meier analysis, cardiovascular death, hospitalization for worsening heart failure, and AF recurrence after catheter ablation did not differ between patients treated with and without RAS inhibitors (all p > 0.05). Catheter ablation in patients with AIC due to AF is associated with a good post-procedural prognosis.IRB information The study was approved by the Research Ethics Committee of the University of Fukui (No. 20220151) and clinical trial registration (UMIN000050391).

Impact of an angulated aorto-septal relationship on cardio-cerebrovascular outcomes in patients undergoing hemodialysis

Aortic and valvular calcification are well-known risk factors for cardio-cerebrovascular events in patients undergoing hemodialysis. We investigated the clinical impact of an angulated aorto-septal angle as a result of aortic elongation due to aortic calcification on cardio-cerebrovascular outcomes in patients undergoing hemodialysis. We investigated 306 patients (mean age 65.4 years, 68% male) who underwent pre-scheduled routine echocardiography between April and September 2018. The angle between the anterior wall of the aorta and the ventricular septal surface (ASA) was quantified. We determined aortic and mitral valve calcification scores based on calcified cardiac changes; the aortic and mitral valve scores ranged between 0-9 and 0-6, respectively. The primary endpoint was a composite including cardio-cerebrovascular events and cardio-cerebrovascular death. The mean duration of dialysis among the patients in this analysis was 9.6 years. The primary endpoint was observed in 54 patients during the observational period (median 1095 days). Multivariable Cox proportional hazards analyses identified left ventricular ejection fraction (per 10% increase: hazard ratio [HR] 0.67; 95% confidential interval [CI] 0.53-0.84, P = 0.001), left ventricular mass index (per 10 g/m2 increase: HR 1.14; 95% CI 1.05-1.24, P = 0.001), ASA (per 10 degree increase: HR 0.69; 95% CI 0.54-0.88; P = 0.003), and aortic valve calcification score (HR 1.15; 95% CI 1.04-1.26, P = 0.005) as independent determinants of the primary endpoint. Kaplan-Meier analysis showed a higher incidence of the primary endpoint in patients with ASA <119.4 degrees than those with ASA ≥119.4 degrees (Log-rank P < 0.001). An angulated aorto-septal angle is an independent risk factor for cardio-cerebrovascular events and cardio-cerebrovascular death in patients undergoing hemodialysis.

Dual tachyarrhythmia: Ventricular fibrillation induced by atrial tachyarrhythmia in a patient with hypertrophic cardiomyopathy

A patient with hypertrophic cardiomyopathy experienced cardiopulmonary arrest. An automated external defibrillator administered defibrillation for ventricular fibrillation (A). The pacemaker recorded atrial tachycardia with a rapid ventricular response before the patient collapsed (B). After a few minutes, the pacemaker records dual tachyarrhythmia, characterized by the simultaneous presence of ventricular fibrillation (VF) and atrial fibrillation (AF) (C). This case demonstrates that VF induced by atrial tachyarrhythmia could contribute to AF-related sudden cardiac death.

Long-Term Clinical Outcome After Alcohol Septal Ablation and Its Periprocedural Predictive Factors in Japan - A Retrospective Observational Study

BACKGROUND

Evidence is limited regarding long-term clinical outcomes after alcohol septal ablation (ASA) for patients with hypertrophic obstructive cardiomyopathy and its periprocedural predictive factors in Japan.

METHODS AND RESULTS

This retrospective observational study included 44 patients who underwent ASA between 1998 and 2022 in a single center. We evaluated the periprocedural change in variables and long-term clinical outcomes after the procedure. The primary outcome was a composite of cardiovascular death or hospitalization for heart failure. The secondary outcome was all-cause death. Using multivariable Poisson regression with robust error variance, we predicted underlying periprocedural factors related to primary outcome development. ASA decreased the median pressure gradient at the left ventricular outflow tract from 88 to 33 mmHg and reduced moderate or severe mitral regurgitation (MR), present in 53% of patients before ASA, to 16%. Over a median 6-year follow-up, the cumulative incidence of the primary outcome at 5 and 10 years was 16.5% and 25.6%, respectively. After multivariable analysis, moderate or severe MR after ASA was significantly associated with the primary outcome (relative risk 8.78; 95% confidence interval 1.34-57.3; P=0.024). All-cause mortality after ASA was 15.1% and 28.9% at 5 and 10 years, respectively.

CONCLUSIONS

This study presents long-term clinical outcomes after ASA in Japan. Moderate or severe MR after ASA was significantly associated with the composite of cardiovascular death or hospitalization for heart failure.

The efficacy of right ventricular pacing for symptomatic left mid-ventricular obstruction

The serial changes in intraventricular pressure gradient in the left ventricle and NYHA functional classification in each case. Both the left intraventricular pressure gradient and symptoms improved after right ventricular pacing. In one case, the left intraventricular pressure gradient disappeared immediately after right ventricular pacing, while in the others it disappeared during the chronic phase, more than a year later.

High-risk imaging characteristics in left ventricular apex for the life-threatening arrhythmic events in Japanese hypertrophic cardiomyopathy patients

Left ventricular (LV) apical aneurysm is known to be associated with the life-threatening arrhythmic events in hypertrophic cardiomyopathy (HCM). However, the current 2014 ESC guideline has not included apical aneurysm as a major risk factor for sudden cardiac death and 2018 JCS guideline includes it only as a modulator, while it has been included as a new major risk marker in 2020 AHA/ACC guideline. Therefore, we sought to identify high-risk imaging characteristics in LV apex which is associated with a higher occurrence of ventricular tachycardia/fibrillation (VT/VF). In 99 consecutive Japanese HCM patients (median age, 65 years; 59 males) undergoing implantable cardioverter-defibrillator (ICD) implantation for primary prevention following cardiac magnetic resonance including late gadolinium enhancement (LGE), the occurrence of appropriate ICD interventions for VT/VF was evaluated for 6.2 (median) years after ICD implantation. Overall, appropriate ICD interventions occurred in 43% with annual rates of 7.0% for appropriate interventions. Kaplan-Meier analysis demonstrated that the presence of LV apical aneurysm was significantly associated with a higher occurrence of appropriate interventions (annual rates 18.9% vs. 6.4%, P = 0.013). Similarly, patients with high LV mid-to-apex pressure gradient (annual rates 14.9% vs. 6.2%, P = 0.022) and presence of apical LGE (annual rates 10.9% vs. 4.0%, P = 0.001) experienced appropriate interventions more frequently. An aneurysm, high-pressure gradient, and LGE in an apex are associated with VT/VF. These characteristics in apex should be kept in mind when implanting ICD in Japanese HCM patients as a primary prevention.

Hypertrophic Cardiomyopathy Predicts Thromboembolism and Heart Failure in Patients With Nonvalvular Atrial Fibrillation - A Prospective Analysis From the Hokuriku-Plus AF Registry

BACKGROUND

The prognostic effect of concomitant hypertrophic cardiomyopathy (HCM) on adverse events in patients with atrial fibrillation (AF) has not been evaluated in a multicenter prospective cohort study in Japan.

METHODS AND RESULTS

Using the Hokuriku-Plus AF Registry, 1,396 patients with nonvalvular AF (1,018 men, 72.3±9.7 years old) were assessed prospectively; 72 (5.2%) had concomitant HCM. During a median follow-up of 5.0 years (interquartile range 3.5-5.3 years), 79 cases of thromboembolism (1.3 per 100 person-years) and 192 of heart failure (HF) (3.2 per 100 person-years) occurred. Kaplan-Meier analysis revealed that the HCM group had a significantly greater incidence of thromboembolism (P=0.002 by log-rank test) and HF (P<0.0001 by a log-rank test) than the non-HCM group. The Cox proportional hazards model demonstrated that persistent AF (adjusted hazard ratio 2.98, 95% confidence interval 1.56-6.21), the CHA2DS2-VASc score (1.35, 1.18-1.54), and concomitant HCM (2.48, 1.16-4.79) were significantly associated with thromboembolism. Conversely, concomitant HCM (2.81, 1.72-4.43), older age (1.07, 1.05-1.10), lower body mass index (0.95, 0.91-0.99), a history of HF (2.49, 1.77-3.52), and lower left ventricular ejection fraction (0.98, 0.97-0.99) were significantly associated with the development of HF.

CONCLUSIONS

Concomitant HCM predicts the incidence of thromboembolism and HF in AF patients.

End-stage Hypertrophic Cardiomyopathy with Advanced Heart Failure in Patients Carrying MYH7 R453 Variants: A Case Series

The MYH7 R453 variant has been identified in inherited hypertrophic cardiomyopathy (HCM) and is associated with sudden death and a poor prognosis. The detailed clinical course of HCM with the MYH7 R453 variant, from a preserved to a reduced left ventricular ejection fraction, has not been reported. We identified the MYH7 R453C and R453H variants in three patients who progressively developed advanced heart failure requiring circulatory support and summarized the clinical course and echocardiographic parameters of these patients over the years. Because of the rapid disease progression, we consider genetic screening for patients with HCM imperative for future prognosis stratification.

Prognostic Role of Circulating LTBP-2 in Patients With Dilated Cardiomyopathy: A Novel Biomarker Reflecting Extracellular Matrix LTBP-2 Accumulation

BACKGROUND

Dilated cardiomyopathy (DCM) is a life-threatening disease related to heart failure. Extracellular matrix proteins have an important role in the pathogenesis of DCM. Latent transforming growth factor beta-binding protein 2 (LTBP-2), a type of extracellular matrix protein, has not been investigated in DCM.

METHODS

First, we compared plasma LTBP-2 levels in 131 patients with DCM who underwent endomyocardial biopsy and 44 controls who were matched for age and sex and had no cardiac abnormalities. Next, we performed immunohistochemistry for LTBP-2 on endomyocardial biopsy specimens and followed the DCM patients for ventricular assist device (VAD) implantation, cardiac death, and all-cause death.

RESULTS

Patients with DCM had elevated plasma LTBP-2 levels compared with controls (P < 0.001). Plasma LTBP-2 levels were positively correlated with LTBP-2-positive fraction in the myocardium from the biopsy specimen. When patients with DCM were divided into 2 groups according to LTBP-2 levels, Kaplan-Meier analysis demonstrated that patients with high plasma LTBP-2 were associated with increased incidences of cardiac death/VAD and all-cause death/VAD. In addition, patients with high myocardial LTBP-2-positive fractions were associated with increased incidences of these adverse outcomes. Multivariable Cox proportional hazard analysis showed that plasma LTBP-2 and myocardial LTBP-2-positive fraction were independently associated with adverse outcomes.

CONCLUSIONS

Circulating LTBP-2 can serve as a biomarker to predict adverse outcomes, reflecting extracellular matrix LTBP-2 accumulation in the myocardium in DCM.

Potential of non-contrast stress T1 mapping for the assessment of myocardial injury in hypertrophic cardiomyopathy

BACKGROUND

Ischemia of the hypertrophied myocardium due to microvascular dysfunction is related to a worse prognosis in hypertrophic cardiomyopathy (HCM). Stress and rest T1 mapping without contrast agents can be used to assess myocardial blood flow. Herein, we evaluated the potential of non-contrast stress T1 mapping in assessing myocardial injury in patients with HCM.

METHODS

Forty-five consecutive subjects (31 HCM patients and 14 control subjects) underwent cardiac magnetic resonance (CMR) at 3T, including cine imaging, T1 mapping at rest and during adenosine triphosphate (ATP) stress, late gadolinium enhancement (LGE), and phase-contrast (PC) cine imaging of coronary sinus flow at rest and during stress to assess coronary flow reserve (CFR). PC cine imaging was performed on 25 subjects (17 patients with HCM and 8 control subjects). Native T1 values at rest and during stress were measured using the 16-segment model, and T1 reactivity was defined as the change in T1 values from rest to stress.

RESULTS

ATP stress induced a significant increase in native T1 values in both the HCM and control groups (HCM: p < 0.001, control: p = 0.002). T1 reactivity in the HCM group was significantly lower than that in the control group (4.2 ± 0.3% vs. 5.6 ± 0.5%, p = 0.044). On univariate analysis, T1 reactivity correlated with native T1 values at rest, left ventricular mass index, and CFR. Multiple linear regression analysis demonstrated that only CFR was independently correlated with T1 reactivity (β = 0.449; 95% confidence interval, 0.048-0.932; p = 0.032). Furthermore, segmental analysis showed decreased T1 reactivity in the hypertrophied myocardium and the non-hypertrophied myocardium with LGE in the HCM group.

CONCLUSIONS

T1 reactivity was lower in the hypertrophied myocardium and LGE-positive myocardium compared to non-injured myocardium. Non-contrast stress T1 mapping is a promising CMR method for assessing myocardial injury in patients with HCM. Trial registration Retrospectively registered.

Regional Variation in the Clinical Practice and Prognosis in Patients With Heart Failure With Reduced Ejection Fraction in Japan - A Report From the Japanese Registry of Acute Decompensated Heart Failure (JROADHF)

BACKGROUND

The present study aimed to clarify the regional variations in clinical practice and the prognosis of patients with heart failure with reduced ejection fraction (HFrEF) in Japan using the Japanese Registry of Acute Decompensated Heart Failure (JROADHF).

METHODS AND RESULTS

We recruited data of hospitalized patients with HFrEF (n=4,329) from the JROADHF. The patients were divided into 6 groups based on the region of Japan where they were hospitalized: Hokkaido-Tohoku (n=504), Kanto (n=958), Chubu (n=779), Kinki (n=902), Chugoku-Shikoku (n=446), and Kyushu (n=740). We compared the patients' characteristics, including etiology of HF and prognosis after discharge. The age of the patients was lowest in the Kanto and Kinki regions. In contrast, there were no differences in the prevalence of comorbidities, levels of B-type natriuretic peptide, or left ventricular EF among the 6 groups. Post-discharge cardiospecific prognosis, specifically, the composite of cardiac death or HF hospitalization, cardiac death, and HF hospitalization, was comparable among the 6 regions.

CONCLUSIONS

There were no differences in cardiospecific prognosis in patients with HFrEF among the 6 regions in Japan.

Predictive Factors for Decreasing Left Ventricular Ejection Fraction and Progression to the Dilated Phase of Hypertrophic Cardiomyopathy

Patients with hypertrophic cardiomyopathy (HCM) may progress to the dilated phase (DHCM). This study aimed to identify the predictive factors for DHCM progression, including left ventricular (LV) ejection fraction (LVEF < 50%) or decreased LV contraction (LVEF < 60%). The study included 291 patients enrolled in our hospital's HCM registry who were grouped based on their poststudy LVEF (LVEF of ≥60%, 50-59%, and <50%). Predictive factors of an LVEF of <50% or <60% were determined. Further, the effects of percutaneous transluminal septal myocardial ablation (PTSMA) on long-term systolic LV function and DHCM development were investigated. LVEF was ≥60%, 50-59%, and <50% in 239, 33, and 19 patients, respectively, during the follow-up period (mean: 64.9 months). Multivariate analyses indicated baseline atrial fibrillation (AF), nonsustained ventricular tachycardia (NSVT), and left ventricular diameter at end-systole (LVDs) as significant predictors of DHCM. Using a scoring method based on AF, NSVT, and LVDs, patients with 2 and 3 points had a significantly higher risk of developing DHCM. PTSMA in 78 HCM patients demonstrated no significant effect on long-term LVEF changes or DHCM development. We concluded that AF, NSVT, and LVDs are significant predictors of DHCM development. However, a validation study with a larger population is required.

A novel compound heterozygous variant in ALPK3 induced hypertrophic cardiomyopathy: a case report

Background

Malignant hypertrophic cardiomyopathy (HCM) phenotypes have potential risks of severe heart failure, fatal arrhythmia, and sudden cardiac death. Therefore, it is critical to predict the clinical outcomes of these patients. It was reported recently that the alpha kinase 3 (ALPK3) gene was involved in the occurrence of HCM. Herein we reported a girl with HCM, while whole-exome sequencing found novel compound heterozygous variants in ALPK3 gene, which identified a potential association.

Case presentation

We reported a 14-year-girl who suffered from clinical manifestations of cardiac failure, with sudden cardiac arrest before admission. The heartbeat recovered after cardiopulmonary resuscitation, though she remained unconscious without spontaneous breath. The patient stayed comatose when she was admitted. Physical examination indicated enlargement of the heart boundary. Laboratory results revealed a significant increment of myocardial markers, while imaging demonstrated hypertrophy of the left heart and interventricular septum. Whole-exome sequencing (WES) identified a compound heterozygous variant in ALPK3 gene consisting of c.3907_3922del and c.2200A>T, which was inherited from her parents. Both variants (p.G1303Lfs*28 and p.R734*) were disease-causing evaluated by MutationTaster (probability 1.000). The crystal structure of the complete amino acid sequence is predicted and evaluated by AlphaFold and SWISS-MODEL software (July, 2022), which revealed three domains. Moreover, both variants resulted in a wide protein-truncating variant and damaged protein function. Thus, a novel compound heterozygous variant in ALPK3 associated with HCM was diagnosed.

Conclusion

We described a young patient with ALPK3-associated HCM who experienced sudden cardiac arrest. Through WES, we identified a compound heterozygous variant in the ALPK3 gene, c.3907_3922del and c.2200A>T, which were inherited from the patient's parents and resulted in a truncated protein, indirectly causing the symptoms of HCM. In addition, WES provided clues in evaluating potential risks of gene variants on fatal clinical outcomes, and the nonsense and frameshift variants of ALPK3 were related to adverse clinical outcomes in HCM patients, which required implantable cardioverter defibrillator (ICD) timely.

Genetic Testing for Cardiomyopathy in Japan 2022: Current Status and Issues of Precision Medicine

Although many causative genes for primary cardiomyopathy have been identified, the use of genetic testing in routine practice is limited in Japan presently. Genetic diagnosis has been reported to be useful for early diagnosis through cascade genetic screening in the family, differentiating secondary cardiomyopathies, and predicting prognosis in some patients; nonetheless, the acquisition of genetic information for cardiomyopathy is stagnating in actual clinical practice. There seem to be a number of reasons for this phenomenon, and although the use of next-generation sequencers has resolved some of the past issues, the importance of pathogenicity studies of variants that are identified is growing. To ensure that patients with cardiomyopathy and their relatives can receive precision medicine, the results of genetic analysis linked to clinical information need to be collected, and a database of variants in Japanese people needs to be established.

Disease modeling of desmosome-related cardiomyopathy using induced pluripotent stem cell-derived cardiomyocytes

Cardiomyopathy is a pathological condition characterized by cardiac pump failure due to myocardial dysfunction and the major cause of advanced heart failure requiring heart transplantation. Although optimized medical therapies have been developed for heart failure during the last few decades, some patients with cardiomyopathy exhibit advanced heart failure and are refractory to medical therapies. Desmosome, which is a dynamic cell-to-cell junctional component, maintains the structural integrity of heart tissues. Genetic mutations in desmosomal genes cause arrhythmogenic cardiomyopathy (AC), a rare inheritable disease, and predispose patients to sudden cardiac death and heart failure. Recent advances in sequencing technologies have elucidated the genetic basis of cardiomyopathies and revealed that desmosome-related cardiomyopathy is concealed in broad cardiomyopathies. Among desmosomal genes, mutations in PKP2 (which encodes PKP2) are most frequently identified in patients with AC. PKP2 deficiency causes various pathological cardiac phenotypes. Human cardiomyocytes differentiated from patient-derived induced pluripotent stem cells (iPSCs) in combination with genome editing, which allows the precise arrangement of the targeted genome, are powerful experimental tools for studying disease. This review summarizes the current issues associated with practical medicine for advanced heart failure and the recent advances in disease modeling using iPSC-derived cardiomyocytes targeting desmosome-related cardiomyopathy caused by PKP2 deficiency.

Nationwide Temporal Trends in Clinical Characteristics and Treatment of Dilated Cardiomyopathy From 2003 to 2013 in Japan - A Report From Clinical Personal Records

BACKGROUND

Little is known about nationwide temporal trends in the clinical characteristics and treatment of dilated cardiomyopathy (DCM) in Japan.

METHODS AND RESULTS

We collected data regarding demographics, echocardiography, and treatment of DCM between 2003 to 2013 from Clinical Personal Records, a national registry organized by the Japanese Ministry of Health, Labour, and Welfare. Among the 40,794 DCM patients screened, 27,702 with left ventricular ejection fraction (LVEF) <50% and age ≥18 years were enrolled in this study and divided into 3 groups according to registration year: Group 1, 2003-2005 (10,006 patients); Group 2, 2006-2010 (11,252 patients); and Group 3, 2011-2013 (6,444 patients). Over time, there were decreases in age at registration (mean [±SD] 58.6±13.0 vs. 56.8±13.8 vs. 56.2±13.8 years; P<0.001) and LVEF (33.5±10.0% vs. 31.1±9.9% vs. 29.2± 9.7%; P<0.001), and an increase in patients with New York Heart Association Class III-IV (28.2% vs. 35.2% vs. 41.0%; P<0.001). The use of β-blockers (59.1% vs. 79.3% vs. 87.8%; P<0.001) and mineralocorticoid receptor antagonists (30.6% vs. 35.8% vs. 39.7%; P<0.001) increased over time. In multivariate analysis, male sex, systolic blood pressure, chronic kidney disease, hemoglobin, and registration year were positively associated, whereas age and LVEF were negatively associated, with β-blocker prescription.

CONCLUSIONS

Although the clinical characteristics of DCM changed, the implementation of optimal medical therapy for DCM increased from 2003 to 2013 in Japan.

Development and validation of nomogram for unplanned ICU admission in patients with dilated cardiomyopathy

Objective

Unplanned admission to the intensive care unit (ICU) is the major in-hospital adverse event for patients with dilated cardiomyopathy (DCM). We aimed to establish a nomogram of individualized risk prediction for unplanned ICU admission in DCM patients.

Methods

A total of 2,214 patients diagnosed with DCM from the First Affiliated Hospital of Xinjiang Medical University from January 01, 2010, to December 31, 2020, were retrospectively analyzed. Patients were randomly divided into training and validation groups at a 7:3 ratio. The least absolute shrinkage and selection operator and multivariable logistic regression analysis were used for nomogram model development. The area under the receiver operating characteristic curve, calibration curves, and decision curve analysis (DCA) were used to evaluate the model. The primary outcome was defined as unplanned ICU admission.

Results

A total of 209 (9.44%) patients experienced unplanned ICU admission. The variables in our final nomogram included emergency admission, previous stroke, New York Heart Association Class, heart rate, neutrophil count, and levels of N-terminal pro b-type natriuretic peptide. In the training group, the nomogram showed good calibration (Hosmer-Lemeshow χ 2 = 14.40, P = 0.07) and good discrimination, with an optimal-corrected C-index of 0.76 (95% confidence interval: 0.72-0.80). DCA confirmed the clinical net benefit of the nomogram model, and the nomogram maintained excellent performances in the validation group.

Conclusion

This is the first risk prediction model for predicting unplanned ICU admission in patients with DCM by simply collecting clinical information. This model may assist physicians in identifying individuals at a high risk of unplanned ICU admission for DCM inpatients.

Estimating the prevalence, clinical characteristics, and treatment patterns of hypertrophic cardiomyopathy in Japan: A nationwide medical claims database study

BACKGROUND

Limited data are available regarding therapies for hypertrophic cardiomyopathy (HCM). This study assessed the prevalence, clinical characteristics, and treatment patterns of HCM in Japan.

METHODS

This retrospective database study analyzed data from 438 hospitals in the Japan Medical Data Vision database from 2016 to 2020. We identified 3913 patients (15 %) with obstructive HCM (oHCM) and 21,714 patients (85 %) with nonobstructive HCM (nHCM).

RESULTS

The estimated total number of patients with oHCM and nHCM in 2020 among Japanese hospitals was 8500 and 43,500, respectively. The prevalence of oHCM and nHCM steadily increased by 27 % and 12 %, respectively, from 2016 to 2020, with a 1:5.2 ratio of oHCM to nHCM in 2020. The mean age of the oHCM and nHCM populations was 72 and 70 years, respectively, and comorbidities included atrial fibrillation (AF) (oHCM, 33.8 %; nHCM, 32.2 %), other arrythmia (30.1 %; 27.6 %), and stroke (16.6 %; 16.4 %). Furthermore, 45.0 % of oHCM and 37.7 % of nHCM patients had undergone at least one hospitalization. A substantial number of HCM patients aged between 20 and 59 years reported AF (oHCM, 17-37 %; nHCM, 4-24 %) and stroke (oHCM, 0-12 %; nHCM, 3-10 %). β-blockers (oHCM, 64.0 %; nHCM, 42.1 %) were the most frequently prescribed treatment, followed by Na channel blockers (29.5 %; 5.7 %), calcium channel blockers (18.1 %; 8.8 %), direct oral anticoagulants (14.5 %; 15.2 %), and warfarin (11.0 %; 11.4 %).

CONCLUSIONS

This study provides important information on the current epidemiological and clinical characteristics of HCM in Japan.

Left atrial strain assessment using cardiac computed tomography in patients with hypertrophic cardiomyopathy

PURPOSE

To evaluate left atrial (LA) function in patients with hypertrophic cardiomyopathy (HCM) by LA strain assessment using cardiac computed tomography (CT-derived LA strain).

MATERIALS AND METHODS

This was a retrospective study of 34 patients with HCM and 31 non-HCM patients who underwent cardiac computed tomography (CT) using retrospective electrocardiogram-gated mode. CT images were reconstructed every 5% (0-95%) of the RR intervals. CT-derived LA strain (reservoir [LASr], conduit [LASc], and booster pump strain [LASp]) were semi-automatically analyzed using a dedicated workstation. We also measured the left atrial volume index (LAVI) and left ventricular longitudinal strain (LVLS) for the left atrial and ventricular functional parameters to assess the relationship with CT-derived LA strain.

RESULTS

CT-derived LA strain significantly correlated with LAVI: r = - 0.69, p < 0.001 for LASr; r = - 0.70, p < 0.001 for LASp; and r = - 0.35, p = 0.004 for LASc. CT-derived LA strain also significantly correlated with LVLS: r = - 0.62, p < 0.001 for LASr; r = - 0.67, p < 0.001 for LASc; and r = - 0.42, p = 0.013 for LASp. CT-derived LA strain in patients with HCM was significantly lower than that in non-HCM patients: LASr (20.8 ± 7.6 vs. 31.7 ± 6.1%, p < 0.001); LASc (7.9 ± 3.4 vs. 14.2 ± 5.3%, p < 0.001); and LASp (12.8 ± 5.7 vs. 17.6 ± 4.3%, p < 0.001). Additionally, CT-derived LA strain showed high reproducibility; inter-observer correlation coefficients were 0.94, 0.90, and 0.89 for LASr, LASc, and LASp, respectively.

CONCLUSION

CT-derived LA strain is feasible for quantitative assessment of left atrial function in patients with HCM.

Additional diagnostic value of electron microscopic examination in endomyocardial biopsy in patients with suspected non-ischemic cardiomyopathy

BACKGROUND

Electron microscopy enables a finely detailed analysis of ultra-structural features, and hence, it generally has an added diagnostic value to light microscopy alone. However, no studies have verified the additional diagnostic value of electron microscopic examination in patients with suspected non-ischemic cardiomyopathy.

METHODS

A total of 294 consecutive patients with non-ischemic cardiomyopathy who underwent endomyocardial biopsy were prospectively enrolled. Patients were divided into three groups according to left ventricular morphology assessed using echocardiography. Myocardial specimens were collected from the right ventricular septum and examined by light microscopy. Electron microscopy was performed subsequently to evaluate the additional diagnostic value.

RESULTS

Altogether, 294 patients were analyzed, including 160 (55 %), 96 (33 %), and 35 (12 %) patients who were diagnosed with primary, secondary, and unclassified cardiomyopathy, respectively. In patients with dilated cardiomyopathy-like morphology, the detection rate of disease-specific histological findings was relatively low compared to that in patients with other cardiac morphologies. The additional diagnostic value of electron microscopy was observed in eight patients, including five with Fabry disease, one with cardiac amyloidosis, one with mitochondrial cardiomyopathy, and one with triglyceride deposit cardiomyovasculopathy. Among the 18 cardiac amyloidosis cases, electron microscopy detected amyloid fibrils in all patients, whereas light microscopy could not detect amyloid deposition in 1 patient. Among one of five patients with Fabry disease, light microscopy did not show obvious vacuolated cardiomyocytes, but zebra bodies were detected by electron microscopy, leading to the diagnosis of cardiac Fabry disease. The diagnostic value of electron microscopic examination in patients with cardiac sarcoidosis was not observed.

CONCLUSIONS

The additional diagnostic value of electron microscopy was observed in patients with secondary cardiomyopathy, in whom light microscopy did not show disease-specific histological findings. Electron microscopy should be performed in cases where secondary cardiomyopathy is strongly suspected with no disease-specific findings by light microscopy.

Transient decrease in the depth of the negative T wave in apical hypertrophic cardiomyopathy is a sign of left anterior descending artery stenosis: a case series

Background

In patients with apical hypertrophic cardiomyopathy (HCM), electrocardiography (ECG) often shows left ventricular hypertrophy (LVH) and a negative T wave. A negative T wave often disappears over time due to degeneration of the apical myocardium. However, there are limited reports on the temporary change of a negative T wave in patients with HCM.

Case summary

We report three apical HCM patients with LVH and T wave inversion on their previous ECG who showed a temporary decrease in the depth of the negative T wave. All of them had significant stenosis of coronary arteries including the left anterior descending artery (LAD). After revascularization for the LAD lesion, their ECG returned to the previous depth of the negative T wave.

Discussion

The cases presented here suggested that a temporary decrease in the depth of the negative T wave in apical HCM patients may be one of the signs of ischaemia in the anterior-apical region caused by severe stenosis of the LAD.

Clinical Features of Heart Failure in Patients With Hypertrophic Cardiomyopathy in a Regional Japanese Cohort - Results From the Kochi RYOMA Study

BACKGROUND

The clinical features of heart failure (HF) in patients with hypertrophic cardiomyopathy (HCM) in Japan have not been fully elucidated.

METHODS AND RESULTS

In 293 patients with HCM (median age at registration, 65 (57-72) years) in a prospective cardiomyopathy registration network in Kochi Prefecture (Kochi RYOMA study), HF events (HF death or hospitalization for HF) occurred in 35 patients (11.9%) (median age, 76 (69-80) years), including 11 HF deaths during a median follow-up of 6.1 years. The 5-year HF events rate was 9.6%. Atrial fibrillation, low percentage of fractional shortening, and high B-type natriuretic peptide level at registration were predictors of HF events. The combination of these 3 factors had a relatively high positive predictive value (55%) for HF events and none of them had a high negative predictive value (99%). There were 4 types of HF profile: left ventricular (LV) systolic dysfunction (40%), severe LV diastolic dysfunction (34%), LV outflow tract obstruction (LVOTO) (20%), and primary mitral regurgitation (MR) (6%). HF deaths occurred in patients with LV systolic dysfunction or LV diastolic dysfunction, but none of patients with LVOTO or primary MR due to additional invasive therapies.

CONCLUSIONS

In a Japanese HCM cohort, HF was an important complication, requiring careful follow-up and appropriate treatment.

Exacerbation of ventricular arrhythmias by continuous positive airway pressure treatment in idiopathic dilated cardiomyopathy

Continuous positive airway pressure (CPAP) therapy can be beneficial in patients with obstructive sleep apnea (OSA) and cardiovascular diseases, reducing arrhythmia frequency and improving cardiac function. We describe a case of moderate OSA with idiopathic dilated cardiomyopathy, in which the frequency of premature ventricular contraction (PVC) and non-sustained ventricular tachycardia (NSVT) increased immediately after initiating CPAP therapy. Although PVC and NSVT are benign cardiac arrhythmias, they are associated with an increased risk of sustained lethal ventricular tachyarrhythmias. Therefore, when initiating CPAP therapy, the possibility of increased arrhythmia should be considered.

Phospholamban p.Arg14del Cardiomyopathy: A Japanese Case Series

Phospholamban p.Arg14del is reported to cause hereditary cardiomyopathy with malignant ventricular tachycardia (VT) and advanced heart failure. However, the clinical courses of Japanese cardiomyopathy patients with phospholamban p.Arg14del remain uncharacterized. We identified five patients with this variant. All patients were diagnosed with dilated cardiomyopathy (DCM), developed end-stage heart failure and experienced VT requiring implantable cardioverter defibrillator discharge. Four patients survived after implantation of a left ventricular assist device (LVAD), while one patient who refused LVAD implantation died of heart failure. Based on the severe course of the disease, we propose genetic screening for phospholamban p.Arg14del in DCM patients.

Myocardial T-Lymphocytes as a Prognostic Risk-Stratifying Marker of Dilated Cardiomyopathy - Results of the Multicenter Registry to Investigate Inflammatory Cell Infiltration in Dilated Cardiomyopathy in Tissues of Endomyocardial Biopsy (INDICATE Study)

BACKGROUND

Dilated cardiomyopathy (DCM) associated with inflammation is diagnosed by endomyocardial biopsy; patients with this have a poorer prognosis than patients without inflammation. To date, standard diagnostic criteria have not been established.

METHODS AND RESULTS

This study analyzed clinical records and endomyocardial biopsy samples of 261 patients with DCM (201 males, median left ventricular ejection fraction; 28%) from 8 institutions in a multicenter retrospective study. Based on the European Society of Cardiology criteria and CD3 (T-lymphocytes) and CD68 (macrophages) immunohistochemistry, 48% of patients were categorized as having inflammatory DCM. For risk-stratification, we divided patients into 3 groups using Akaike Information Criterion/log-rank tests, which can determine multiple cut-off points: CD3+-Low, <13/mm2(n=178, 68%); CD3+-Moderate, 13-24/mm2(n=58, 22%); and CD3+-High, ≥24/mm2(n=25, 10%). The survival curves for cardiac death or left ventricular assist device implantation differed significantly among the 3 groups (10-year survival rates: CD3+-Low: 83.4%; CD3+-Moderate: 68.4%; CD3+-High: 21.1%; Log-rank P<0.001). Multivariate Cox analysis revealed CD3+count as a potent independent predictive factor for survival (fully adjusted hazard ratio: CD3+-High: 5.70, P<0.001; CD3+-Moderate: 2.64, P<0.01). CD3+-High was also associated with poor left ventricular functional and morphological recovery at short-term follow up.

CONCLUSIONS

Myocardial CD3+T-lymphocyte infiltration has a significant prognostic impact in DCM and a 3-tiered risk-stratification model could be helpful to refine patient categorization.

Real-world clinical outcomes of percutaneous transluminal septal myocardial ablation for patients with drug-refractory hypertrophic obstructive cardiomyopathy: results from a retrospective multicenter registry of non-high-volume centers

Percutaneous transluminal septal myocardial ablation (PTSMA) is a well-established interventional therapy for drug-refractory hypertrophic obstructive cardiomyopathy (HOCM) as an alternative to surgical myectomy. Although guidelines recommend that PTSMA should be performed in institutions with extensive experience, it is not centralized to such high-volume centers in real-world clinical practice. Thus, this study aimed to assess the feasibility of PTSMA in non-high-volume centers. We retrospectively examined patients with HOCM who underwent PTSMA between August 2012 and May 2020 at four institutions that experienced fewer than 20 cases of PTSMA procedures. The primary clinical endpoint was a composite of safety (all-cause death, electrical defibrillation for ventricular tachycardia or fibrillation, cardiac tamponade, permanent pacemaker implantation, and repeated interventions) and efficacy endpoints (repeated interventions [PTSMA or surgical myectomy]). Fifty-eight consecutive patients were enrolled. During the 30-day follow-up, no major clinical adverse events were noted except three patients (5.2%) requiring permanent pacemaker implantation for complete atrioventricular block. The percentage of patients with New York Heart Association functional class 1 or 2 significantly increased from 8.6 to 100% (p < 0.001). In the Cox proportional hazard model, left ventricular outflow tract pressure gradient at rest ≥ 30 mmHg (hazard ratio [HR] 6.56; 95% confidence interval [CI] 1.44-29.90; p = 0.015) and mitral regurgitation grade ≥ 3 (HR 10.75; 95% CI 1.81-63.79; p = 0.009) at the 30-day follow-up were associated with a composite of major clinical adverse events. The current study demonstrated that 58 patients who underwent PTSMA in non-high-volume centers had favorable 30-day clinical outcomes, with a primary composite endpoint rate of 5.2%. A prospective study with a larger sample size and longer follow-up is warranted to verify the safety and efficacy of PTSMA in non-high-volume centers.

Relationships of Atrial Fibrillation at Diagnosis and Type of Atrial Fibrillation During Follow-up With Long-Term Outcomes for Heart Failure With Preserved Ejection Fraction

Background: Few data are available regarding the impact of atrial fibrillation (AF) at diagnosis and type of AF during the follow-up period on long-term outcomes in patients with heart failure with preserved ejection fraction (HFpEF).

Methods and Results: In all, 1,697 patients diagnosed as HFpEF between March 2010 and December 2017 were included in this study. At enrollment, 698 (41.1%) patients had AF. Over a median follow-up of 1,017 days, there were no significant differences between patients with and without AF in the adjusted hazard ratio (HR) for all-cause death or admission for heart failure. However, those with AF had a higher risk of stroke (HR 1.831; P=0.003). Of 998 patients with sinus rhythm at enrollment, 139 (13.9%) developed new-onset AF. Predictors of new-onset AF were pulse, hemoglobin, left ventricular end-diastolic dimension, and B-type natriuretic peptide. Compared with sinus rhythm, paroxysmal AF had a similar risk for all-cause death, admission for HF, and stroke; persistent AF had a lower risk of all-cause death (HR 0.701; P=0.015), but a higher risk for admission for HF (HR 1.608; P=0.002); and new-onset AF had a lower risk for all-cause death (HR 0.654; P=0.040), but a higher risk of admission for HF (HR 2.475; P<0.001).

Conclusions: In patients with HFpEF, long-term outcome may differ by type of AF. Physicians need to consider individual risk with regard to AF type.

The association between the clinical severity of heart failure and docosahexaenoic acid accumulation in hypertrophic cardiomyopathy

Objective

Hypertrophic cardiomyopathy (HCM) is a common genetic disease with diverse morphology, symptoms, and prognosis. Hypertrophied myocardium metabolism has not been explored in detail. We assessed the association between myocardium lipid metabolism and clinical severity of heart failure (HF) in HCM using imaging mass spectrometry (IMS).

Results

We studied 16 endomyocardial biopsy (EMB) specimens from patients with HCM. Analysis was conducted using desorption electrospray ionization IMS. The samples were assigned into two cohorts according to the period of heart biopsy (cohort 1, n = 9 and cohort 2, n = 7). In each cohort, samples were divided into two groups according to the clinical severity of HF in HCM: clinically severe and clinically mild groups. Signals showing a significant difference between the two groups were analyzed by volcano plot. In cohort 1, the volcano plot identified four signals; the intensity in the clinically severe group was more than twice that of the mild group. Out of the four signals, docosahexaenoic acid (DHA) showed significant differences in intensity between the two groups in cohort 2 (10,575.8 ± 2750.3 vs. 19,839.3 ± 4803.2, P = 0.025). The intensity of DHA was significantly higher in EMB samples from the clinically severe HCM group than in those from the mild group.

Pathogenic variant of RBM20 in a multiplex family with hypertrophic cardiomyopathy

RBM20 is a disease-causing gene associated with dilated cardiomyopathy (DCM). The proband presented with the dilated phase of hypertrophic cardiomyopathy (HCM), and the mother also suffered from HCM. A missense variant of RBM20, p.Arg636His, previously reported as pathogenic in several families with DCM, was found in both the proband and the mother. Therefore, RBM20 p.Arg636His could be the causative variant for this familial HCM, and RBM20 might be a novel causative gene for HCM.