Comparison of prevalence of apical hypertrophic cardiomyopathy in Japan and the United States

doi:10.1016/j.amjcard.2003.07.027

The American Journal of Cardiology

Volume 92, Issue 10, 15 November 2003, Pages 1183-1186

https://doi.org/10.1016/j.amjcard.2003.07.027 Get rights and content

Abstract

The morphologic apical form of hypertrophic cardiomyopathy (HC), in which left ventricular (LV) wall thickening is confined to the most distal region at the apex, has been regarded as a phenotypic expression of nonobstructive HC largely unique to Japanese patients. To investigate this question further, we directly compared unselected and regional hospital-based cohorts of adult patients with HC ( ≥18 years of age) from Japan (Kochi; n = 100) and from the United States (US) (Minneapolis; n = 361). Japanese and American patients with HC had similar clinical features and did not differ significantly with regard to the severity of symptoms and frequency of outflow obstruction. Although Japanese and American patients also showed similar maximum LV thickness, they differed significantly with respect to the distribution of LV hypertrophy. In particular, the segmental form of HC, with hypertrophy confined to the LV apex, was more frequent in Japanese patients (i.e., apical HC, 15% in Japan vs 3% in US, p <0.0001). Giant negative T waves were also more common in Japanese patients with HC (26% vs 2%, p <0.001), including those with the apical form (64% vs. 30%, p <0.05). Each patient with apical HC had either no or only mild symptoms, and all survived. The morphologic form of nonobstructive HC with hypertrophy limited to the LV apex (apical form of HC) was 5 times more common in an unselected Japanese population. These findings document variability in the phenotypic expression of HC between countries and races, which may be due to differences in environmental factors or genetic background. Patients with the apical form of HC had a benign clinical course.

Section snippets

Patient selection

Consecutively enrolled patients with HC from 2 regional community-based centers were combined for a cohort of 461 patients, including (1) 100 patients from the Kochi prefecture in southwestern Japan evaluated at the Kochi Medical School, and (2) 361 patients from the Minneapolis Heart Institute, a population consisting primarily of Minnesota residents and those from the adjacent states of Wisconsin, Iowa, and North and South Dakota, who were selected as previously reported.20 The United States

Patient characteristics

Clinical and morphologic findings in the 2 HC cohorts are compared in Table 1. Although Japanese patients were more often men and less frequently had outflow obstruction, Japanese and American patients were similar with regard to age, symptom severity, and maximum LV thickness.

Morphologic findings

Fifteen of the 100 patients (15%) in the Japanese cohort and 10 of the 361 patients (3%) in the American cohort had apical hypertrophy (Table 1 and Figure 1). Therefore, the prevalence of apical HC in Japanese patients

Discussion

Japanese investigators first reported apical HC as a morphologic variant of HC characterized by a striking electrocardiographic pattern of particularly deep T-wave inversion in the precordial leads (“ giant negative T waves”) and the distinctive angiographic spade-shaped appearance of the left ventricle at end-diastole. Subsequently, apical HC has been reported with echocardiography from several centers outside of Japan, although the characteristic electrocardiographic pattern is seen

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Ethnic and sex-related differences at presentation in apical hypertrophic cardiomyopathy: An observational cross-sectional study
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We investigated whether ethnicity and sex are associated with different clinical presentations and cardiovascular magnetic resonance (CMR) findings in individuals with apical hypertrophic cardiomyopathy (ApHCM).
A retrospective observational cohort study of consecutive ApHCM patients from a large tertiary referral center in the United Kingdom (UK). Demographic, clinical, 12‑lead electrocardiogram (ECG) and CMR findings were collected. Participants presented in our clinics between 2010 and 2020. ‘Pure’ ApHCM was defined as isolated apical hypertrophy and ‘mixed’ with both apical and septal hypertrophy but with the apical segments of a greater wall thickness. Deep T-wave inversion was defined as ≥5 mm in any electrocardiogram lead.
A total of 150 consecutive ApHCM patients (75% men, 25% women; 37% White, 25% Black, 24% Asian and 15% of Mixed/Other ethnicity) were included. Females were diagnosed at an older age compared to men, had less prominent ECG changes, had higher left atrial area index, and were more hypertensive. Black patients had higher left ventricular mass index, more hypertension, and more of the ‘mixed’ type of ApHCM. The majority of hypertensive male patients showed the ‘mixed’ phenotype.
Individuals of Black ethnicity and hypertensive male patients are more likely to present with mixed apical and basal hypertrophy, whereas White, Asian and non-hypertensive male patients tend to have hypertrophy limited to the apex. Females present at an older age and are less likely to have deep T wave inversion on ECG.
Left ventricular morphologic progression in apical hypertrophic cardiomyopathy
2023, International Journal of Cardiology
Left ventricular (LV) morphologic progression in apical hypertrophic cardiomyopathy (AHC) has not been well studied. We evaluated serial echocardiographic changes in LV morphology.
Serial echocardiograms in AHC patients were assessed. LV morphology was categorized according to the presence of an apical pouch or aneurysm, and LV hypertrophic severity and extent; relative, pure, and apical-mid type defined as mild (<15 mm thickness) apical hypertrophy, significant (≥15 mm) apical hypertrophy, and both apical and midventricular hypertrophy, respectively. Adverse clinical events and late gadolinium enhancement (LGE) extent on cardiac magnetic resonance were evaluated for each morphologic type.
In 41 patients, 165 echocardiograms (maximal interval: 4.2 [IQR, 2.3–11.8] years) were evaluated. Morphologic changes were observed in 19 (46%) patients. Eleven (27%) patients displayed the progression of LV hypertrophy toward pure or apical-mid type. Five (12%) and 6 (15%) patients developed new pouches and aneurysms. Patients with progression tended to be younger (50 ± 15.6 vs 59 ± 14.4 years, P = 0.058) and had a longer period of follow-up (12 [5–14] vs 3 [2–4] years, P < 0.001). During a follow-up of 7.6 (IQR 3.0–12.1) years, 21 (51%) experienced clinical events. The relative, pure, and apical-mid types showed different LGE extents (2%, 6%, and 19%, P = 0.004). Patients with severe hypertrophic and apical involvement showed higher clinical event rates.
About half of AHC patients had a progression of LV morphology to more hypertrophic involvement and/or an apical pouch or aneurysm formation. Advanced AHC morphologic types were associated with higher event rates and scar burdens.
Genetic Testing for Cardiomyopathy in Japan 2022: Current Status and Issues of Precision Medicine
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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.
Estimating the prevalence, clinical characteristics, and treatment patterns of hypertrophic cardiomyopathy in Japan: A nationwide medical claims database study
2023, Journal of Cardiology
Limited data are available regarding therapies for hypertrophic cardiomyopathy (HCM). This study assessed the prevalence, clinical characteristics, and treatment patterns of HCM in Japan.
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).
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 %).
This study provides important information on the current epidemiological and clinical characteristics of HCM in Japan.
Apical myectomy in patients with apical hypertrophic cardiomyopathy and advanced heart failure
2021, Revista Espanola de Cardiologia
Differential contributions of sarcomere and mitochondria-related multigene variants to the endophenotype of hypertrophic cardiomyopathy
2020, Mitochondrion
Hypertrophic cardiomyopathy (HCM) is a multigenic disease that occurs due to various genetic modifiers. We investigated phenotype-based clinical and genetic characteristics of HCM patients using comprehensive genetic tests and rare variant association analysis.
A comprehensive HCM-specific panel, consisting of 82 nuclear DNAs (nDNAs: 33 sarcomere-associated genes, 5 phenocopy genes, and 44 nuclear genes linked to mitochondrial cardiomyopathy) and 37 mitochondrial DNAs (mtDNAs), was analyzed. Rare variant analysis was performed to determine the association of specific genes with different phenotypes.
Among the 212 patients, pathogenic variants in sarcomere-associated genes were more prevalent in non-apical HCM (41.4%, 46/111; P = 0.001) than apical HCM (20.8%, 21/101). Apical HCM exhibits mild phenotypes than non-apical HCM, and it showed fewer numbers of sarcomere mutations than non-apical HCM. Interestingly, inverted mutation frequency of TNNI3 (35%) and MYH7 (9%) was observed in apical HCM.
In a rare variant analysis, MT-RNR2 positively correlated with apical HCM (OR: 1.37, P = 0.025). And, MYBPC3 (sarcomere gene) negatively contributed to apical HCM (OR: 0.54, P = 0.027). On the other hand, both pathogenic mutation (P < 0.05) and rare variants in sarcomere-associated genes (OR: 2.78–3.47, P < 0.05) were related to diastolic dysfunction and left atrium remodeling, which correlated with poor prognosis in HCM patients.
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CardiomyopathyComparison of prevalence of apical hypertrophic cardiomyopathy in Japan and the United States

Abstract

Section snippets

Patient selection

Patient characteristics

Morphologic findings

Discussion

Prog Cardiovasc Dis

Lancet

Am J Cardiol

J Am Coll Cardiol

Am J Cardiol

J Am Coll Cardiol

J Am Coll Cardiol

Am J Cardiol

Am Heart J

J Am Coll Cardiol

J Am Coll Cardiol

Am J Cardiol

J Am Coll Cardiol

Cardiomyopathy
Comparison of prevalence of apical hypertrophic cardiomyopathy in Japan and the United States