Prospective Multicenter Screening With High-Sensitivity Cardiac Troponin T for Wild-Type Transthyretin Cardiac Amyloidosis in Outpatient and Community-Based Settings.

BACKGROUND: High-sensitivity cardiac troponin T (hs-cTnT) was proposed as a simple and useful diagnostic tool for cardiac amyloidosis (CA). We performed exploratory systemic screening using hs-cTnT to detect wild-type transthyretin CA (ATTRwt-CA) in outpatient and community-based settings. METHODS AND RESULTS: This study was a prospective multicenter study including 8 internal medicine clinics in Kochi Prefecture, Japan. Consecutive individuals aged ≥70 years who visited those clinics as outpatients were enrolled. Patients with a prior diagnosis of CA or a history of heart failure hospitalization were excluded. We measured hs-cTnT levels in the enrolled individuals at each clinic, and those with elevated hs-cTnT levels (≥0.03ng/mL) received further detailed examination, including remeasurement of hs-cTnT. The diagnosis of ATTRwt-CA was confirmed by biopsy-proven transthyretin. Of 1,141 individuals enrolled in the study, 55 (4.8%) had elevated hs-cTnT levels. Of the 33 patients who underwent further examination, 22 had elevated hs-cTnT levels at remeasurement. Finally, 2 men were diagnosed with ATTRwt-CA. The prevalence of ATTRwt-CA was 9.1% (2/22) among patients with elevated hs-cTnT levels at two examinations, and at least 0.18% (2/1,141) in the whole study population. CONCLUSIONS: Measurement of hs-cTnT will help to screen for patients with undiagnosed ATTRwt-CA in primary care practice.

Usefulness of high-sensitive cardiac troponin T for evaluating the activity of cardiac sarcoidosis.

Since early intervention using corticosteroids improves prognosis in some patients with cardiac sarcoidosis, early and accurate diagnosis of this clinical condition is important. However, it is still not easy to evaluate the activity of cardiac sarcoidosis in clinical practice. The aim of this study was to determine whether high-sensitive cardiac troponin T (hscTnT) is useful as an additional parameter to standard assessment in patients with cardiac sarcoidosis. Twelve patients who were diagnosed as having cardiac sarcoidosis at our institution were retrospectively studied. Evaluation of patients included clinical examinations, electrocardiography, echocardiography, 67-gallium-citrate (Ga) scintigraphy, 18F-fluoro2-deoxyglucose positron emission tomography (18F-FDG PET) and laboratory data including hs-cTnT, angiotensin-converting enzyme (ACE), lysozyme and B-type natriuretic peptide (BNP). The activity of cardiac sarcoidosis was judged mainly by using 18F-FDG PET. Localized uptake of 18F-FDG, which was considered to be active cardiac sarcoidosis, was seen in 8 patients. Based on the findings of 18F-FDG PET, hs-cTnT was considered to be a reliable parameter: sensitivity and specificity were 87.5% and 75.0%, respectively. The positive predictive value (PPV) and negative predictive value (NPV) were 87.5% and 75.0%, respectively. On the other hand, these values in lysozyme and BNP markers were not as high as those in hs-cTnT. Although an ACE marker and Ga-67 scintigraphy showed specificity and PPV of 100%, both sensitivity and NPV were less than 50%. Furthermore, hs-cTnT levels decreased after steroid therapy in some patients. Hs-cTnT seems to be a useful marker for evaluating the activity of cardiac sarcoidosis.

Inferior acute myocardial infarction due to acute cardiac herniation after right pneumonectomy.

A 69-year-old man underwent right intrapericardial pneumonectomy for lung cancer. After 24 h, he went into shock with inferior acute myocardial infarction. We performed urgent coronary angiography, which revealed total occlusion of the mid-right coronary artery. Intravascular ultrasound showed that the artery seemed to be compressed from the pericardial side. We implanted a coronary stent because the lesion was refractory to balloon dilatation. After the procedure, we performed computed tomography and cardiac herniation was diagnosed. Emergency thoracotomy was performed to return the herniated heart to its normal position. This patient was discharged 38 days after initial surgery.

Plasma metalloproteinase levels and left ventricular remodeling in hypertrophic cardiomyopathy in patients with an identical mutation.

BACKGROUND AND PURPOSE: Although it has been reported that matrix metalloproteinases (MMPs) are associated with left ventricular (LV) remodeling in patients with hypertrophic cardiomyopathy (HCM), the impact of plasma MMP levels in patients with HCM is somewhat vague. METHODS AND SUBJECTS: Plasma levels of MMP-2, MMP-9, and clinical/echocardiographic findings were evaluated in 16 HCM patients with preserved LV ejection fraction (defined as LV ejection fraction more than 50%) caused by an identical frameshift mutation (S593fs: a one-base deletion of a thymidine at nucleotide 11,645) in the cardiac myosin-binding protein C gene. RESULTS: MMP-2 levels were inversely related to LV ejection fraction (r(2)=-37, p=0.01). MMP-9 levels were inversely related to LV end-diastolic dimension (r(2)=-0.24, p=0.06) and positively related to the maximum LV wall thickness (r(2)=0.25, p=0.04). During follow-up period of 4.1 ± 1.2 years, LV ejection fraction decreased from 68.5 ± 7.4% to 64.9 ± 9% (p=0.03). Among clinical, echocardiographic findings at baseline and levels of biomarkers, high MMP-9 levels were only related to the decrease of LV ejection fraction from baseline to follow-up (r(2)=0.39, p=0.009). CONCLUSIONS: MMP-2 levels are related to reduced LV systolic function in HCM patients with preserved LV ejection fraction caused by an identical cardiac myosin-binding protein C gene abnormality. On the other hand, MMP-9 levels are associated with small LV size and the degree of LV hypertrophy and related to the deterioration in LV systolic function during follow-up. These results suggest that MMPs are important in the process of LV remodeling in HCM.

Genetic screening and double mutation in Japanese patients with hypertrophic cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is a primary myocardial disorder with an autosomal-dominant pattern of inheritance mainly caused by single heterozygous mutations in sarcomere genes. Although multiple gene mutations have recently been reported in Western countries, clinical implications of multiple mutations in Japanese subjects are not clear. METHODS AND RESULTS: A comprehensive genetic analysis of 5 sarcomere genes (cardiac ß-myosin heavy chain gene [MYH7], cardiac myosin-binding protein C gene [MYBPC3], cardiac troponin T gene [TNNT2], α-tropomyosin gene [TPM1] and cardiac troponin I gene [TNNI3]) was performed in 93 unrelated patients and 14 mutations were identified in 28 patients. Twenty-six patients had single heterozygosity (20 in MYBPC3, 4 in MYH7, 1 in TNNT2, 1 in TNNI3), whereas 2 proband patients with familial HCM had double heterozygosity: 1 with P106fs in MYBPC3 and R869C in MYH7 and 1 with R945fs in MYBPC3 and E1049D in MYH7. From the results of the family survey and the previous literature on HCM mutations, P106fs, R945fs and R869C seemed to be pathological mutations and E1049D might be a rare polymorphism. The proband patient with P106fs and R869C double mutation was diagnosed as having HCM at an earlier age (28 years of age) than her relatives with single mutation, and had greater wall thickness with left ventricular outflow obstruction. CONCLUSIONS: One double mutation was identified in a Japanese cohort of HCM patients. Further studies are needed to clarify the clinical significance of multiple mutations including phenotypic severity.

Tissue doppler imaging and plasma BNP levels to assess the prognosis in patients with hypertrophic cardiomyopathy.

BACKGROUND: In addition to sudden death, heart failure and stroke due to atrial fibrillation are important in patients with hypertrophic cardiomyopathy (HCM). The aim of the present study was to determine whether Doppler tissue imaging findings and plasma B-type natriuretic peptide (BNP) levels, which are widely used for risk stratification in several cardiovascular diseases, are useful for risk stratification in patients with HCM in a regional cohort. METHODS: One hundred thirty patients (82 men; mean age, 60 ± 16 years) with HCM were enrolled in this study. RESULTS: Twenty end points were observed during a mean follow-up period of 3.7 ± 1.7 years. Septal E/e' ratios and BNP levels in patients with events were higher than those in patients without events (17.4 ± 6.3 vs 10.6 ± 4.3, P < .0001, and 441 ± 304 vs 202 ± 174 pg/mL, P < .0001, respectively). By multivariate logistic regression analysis, a high septal E/e' ratio, in addition to a history of syncope and documentation of atrial fibrillation, was a significant predictor of combined end points. In contrast, plasma BNP levels were not a significant predictor of combined end points. CONCLUSION: Assessment by Doppler tissue imaging is useful for further risk stratification of patients with HCM.

Combined measurements of cardiac troponin I and brain natriuretic peptide are useful for predicting adverse outcomes in hypertrophic cardiomyopathy.

BACKGROUND: Although serum cardiac troponin I (cTnI) and plasma brain natriuretic peptide (BNP) have become clinically important tools as diagnostic and prognostic markers for ischemic heart disease and heart failure, the usefulness of these biomarkers for risk stratification of hypertrophic cardiomyopathy (HCM) is not clear. METHODS AND RESULTS: We studied 167 patients with HCM, and cTnI and BNP were measured. During follow-up (38.5 months), 20 patients suffered from cardiovascular events: HCM-related deaths in 6, hospitalization for heart failure in 8, embolic stroke in 5 and 1 patient with spontaneous sustained ventricular tachycardia. Patients with high cTnI values (≥0.04 ng/ml) had more frequent cardiovascular events than did those with low cTnI values (P=0.008). Similarly, there were more frequent adverse events in the high BNP group (≥200 pg/ml) than in the low BNP group (P=0.002). When groups were allocated according to both cTnI and BNP measurements, serum cTnI used in conjunction with BNP further improved the prognostic value; patients with both high cTnI and BNP values had an 11.7-fold increased risk of cardiovascular events compared with those with both low cTnI and BNP values. CONCLUSIONS: CTnI and BNP are useful parameters for identifying patients at risk for clinical deteriorations, and combined measurements of these biomarkers further improves the prognostic value of increased cardiovascular events in HCM.

Effect of left ventricular reverse remodeling on long-term prognosis after therapy with angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers and ß blockers in patients with idiopathic dilated cardiomyopathy.

It remains unknown whether left ventricular (LV) reverse remodeling (LVRR) after therapy with angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers and ß blockers is correlated with prognosis in patients with idiopathic dilated cardiomyopathy. Forty-two patients with idiopathic dilated cardiomyopathy treated with the therapy were studied. Complete left ventricular reverse remodeling was defined as LV end-diastolic dimension ≤ 55 mm and fractional shortening ≥ 25% at the last echocardiographic assessment. The incidence of complete LVRR was significantly higher in patients who survived than in those who died or underwent heart transplantation. Patients were divided into 3 groups: death or transplantation, alive with complete LVRR, and alive without complete LVRR. Although patients who died or underwent transplantation did not show any LV improvements, those with complete LVRR showed significant improvements at 1 to 6 months after starting the therapy. Patients without complete LVRR also showed small but significant improvements at 1 to 6 months. The decrease in LV end-systolic dimension from the initial value to that at 1 to 6 months was an independent determinant of future cardiac death or transplantation. In conclusion, complete LVRR is related to favorable prognosis in patients with idiopathic dilated cardiomyopathy. The extent of left ventricular reverse remodeling at 1 to 6 months after starting the therapy is predictive of long-term prognosis.

Turbulent left-to-right shunt flow through the interatrial septum suggesting high left atrial pressure in patients with heart failure with preserved ejection fraction.

Lutembacher's syndrome is a combination of interatrial septal (IAS) defect or patent foramen ovale (PFO), associated with mitral stenosis. High left atrial (LA) pressure in mitral stenosis exaggerates left-to-right shunt in patients with interatrial communication. We present a case of heart failure with preserved ejection fraction. Echocardiography revealed normal left ventricular systolic function without mitral stenosis and turbulent left-to-right shunt through the IAS. The peak velocity of the shunt flow was 2.3 m/s and the estimated pressure gradient was 22 mmHg, indicating high LA pressure. The presence of turbulent left-to-right shunt through the IAS is helpful for detecting high LA pressure.

Abdominal visceral fat thickness measured by ultrasonography predicts the presence and severity of coronary artery disease.

Abdominal visceral fat plays a critical role in the pathogenesis of metabolic syndrome, which is a risk factor for coronary artery disease (CAD). Ultrasonography (US) distinctively quantifies visceral fat and subcutaneous fat. We measured the maximum preperitoneal visceral fat thickness (Vmax) and the minimum subcutaneous fat thickness (Smin) by US in 185 patients who underwent coronary angiography. Although the 144 patients with CAD had larger Vmax (8.8 ± 3.6 vs. 6.4 ± 2.8 mm; p < 0.001) than those without, there was no difference in Smin. Vmax of 6.9 mm or higher was an independent predictor of CAD (odds ratio, 3.710, p = 0.008) by multiple logistic regression analysis. Vmax significantly correlated with the number of diseased vessels. Assessment of abdominal visceral fat by US gives us incremental information beyond conventional risk factors for predicting CAD in routine clinical practice.

Gender-specific differences in the clinical features of hypertrophic cardiomyopathy in a community-based Japanese population: results from Kochi RYOMA study.

OBJECTIVES: Hypertrophic cardiomyopathy (HCM) is a primary myocardial disorder with a broad spectrum of clinical features. Although gender may be one of the important modifying factors in HCM, there has been little information on gender differences. METHODS: We investigated gender-specific differences in the clinical features of HCM in a community-based Japanese population. We established cardiomyopathy registration in Kochi Prefecture named Kochi RYOMA study consisting of 9 hospitals as an unselected regional Japanese population. RESULTS: 261 patients with diagnosis of HCM were registered. At registration, 88 patients (34%) were women. Female patients were more frequently diagnosed as having HCM at ≥65 years (41% versus 27%) and had a higher ratio of familial HCM (35% versus 19%). More female patients had diagnosis of HCM due to cardiac symptoms (64% versus 40%) and were symptomatic both at diagnosis and at registration. Although the prevalence of atrial fibrillation was not different between males and females, embolic events occurred less frequently in female patients at registration than in male patients (2% versus 10%). In female patients, there were more obstructive HCM patients and fewer patients with apical HCM. Left ventricular and left atrial diameters were smaller and fractional shortening was higher in females than in males. CONCLUSIONS: The manifestations of HCM in unselected Japanese patients differed in men and women, which suggest that hormonal, social, and genetic factors may influence the clinical presentation of HCM.

A frameshift deletion mutation in the cardiac myosin-binding protein C gene associated with dilated phase of hypertrophic cardiomyopathy and dilated cardiomyopathy.

OBJECTIVES: A few studies reported that some mutations in the cardiac myosin-binding protein C (MyBPC) gene were associated with dilated phase of hypertrophic cardiomyopathy (D-HCM) resembling dilated cardiomyopathy (DCM). We studied 5 unrelated cardiomyopathy probands caused by an identical mutation in the MyBPC gene. The results of clinical and genetic investigations in these patients are presented in this paper. METHODS: We analyzed MyBPC gene in DCM patients as well as patients with HCM. RESULTS: An R945fs/105 mutation, 2-base deletion at nucleotides 18,535 and 18,536, was identified in 4 of the 176 HCM probands and in 1 of the 54 DCM probands. Genetic analysis in relatives of those probands revealed another one member with this mutation. A total of 6 subjects had R945fs/105 mutation. The mean age of these six patients at diagnosis was 61 years. At initial evaluation, three of them were diagnosed as having HCM with normal left ventricular (LV) systolic function. The other two patients already had D-HCM. The remaining one patient was diagnosed as having DCM because of reduced LV systolic function (ejection fraction=31%) without increased LV wall thickness. During follow-up (7.6 years), all three patients with impaired LV systolic function were admitted for treatment of heart failure and/or sustained ventricular tachycardia. Finally, one patient with the diagnosis of D-HCM died of heart failure. CONCLUSIONS: The patients with this mutation may develop LV systolic dysfunction and suffer from cardiovascular events through mid-life and beyond.

Clinical features of the dilated phase of hypertrophic cardiomyopathy in comparison with those of dilated cardiomyopathy.

BACKGROUND: Although the dilated phase of hypertrophic cardiomyopathy (D-HCM) characterized by left ventricular (LV) systolic dysfunction and cavity dilatation has been reported to be a poor prognosis, this is now in contrast to the improved prognosis of dilated cardiomyopathy (DCM) in the era of advancements in heart failure management. There has been no investigation of the clinical features of D-HCM compared with those of DCM from the point of management of systolic dysfunction. HYPOTHESIS: The aim of this study was to investigate the clinical features of D-HCM in comparison with those of DCM in a single institute. METHODS: We studied 20 consecutive patients with D-HCM (global ejection fraction < 50%) and 115 consecutive patients with DCM. RESULTS: At diagnosis of D-HCM, 8 (40%) of the D-HCM patients already experienced dyspnea (New York Heart Association [NYHA] class >or= III). Left atrial diameter was larger and prevalence of atrial fibrillation was higher in the D-HCM group, although LV size was larger and LV ejection fraction was lower in the DCM group. During the follow-up period (4.0 years), 11 (55%) of the patients with D-HCM died. The 5-year survival rate from all-cause mortality including cardiac transplantation was 45.6% in patients with D-HCM vs 81.6% in patients with DCM (log-rank P = .0001). CONCLUSIONS: Patients with D-HCM were more symptomatic at diagnosis, although LV dilatation and impaired fractional shortening seemed more severe in patients with DCM. The prognosis for D-HCM patients was worse than that for patients with DCM despite similar or even more intensive treatment for heart failure.

Impact of metalloproteinases on left ventricular remodeling and heart failure events in patients with hypertrophic cardiomyopathy.

BACKGROUND: The impact of matrix metalloproteinase (MMP) on left ventricular (LV) remodeling and heart failure events is unresolved in patients with hypertrophic cardiomyopathy (HCM). METHODS AND RESULTS: Plasma levels of MMP-2, MMP-9, tissue inhibitor of metalloproteinase (TIMP)-1 and clinical findings and heart failure events were evaluated in 41 HCM patients, including 8 with LV systolic impairment. Plasma B-type natriuretic peptide (BNP) levels were also measured. MMP-2 levels in patients with severe symptoms were higher than that in those with no or mild symptoms. The levels of MMP-2 and TIMP-1 were positively related to LV end-systolic and left atrial dimensions, and inversely related to LV ejection fraction. MMP-2 levels were positively related to BNP levels (r=0.52, P=0.0009). However, MMP-9 levels were not related to echocardiographic parameters and plasma BNP levels. Six patients had complicated heart failure events during the follow-up period of 3.2+/-0.7 years. Patients with high plasma MMP-2 levels (>1,170 ng/ml) revealed a poorer prognosis than those with low MMP-2 levels. CONCLUSIONS: Elevated levels of MMP-2 were related to LV remodeling and poor prognosis in patients with HCM. These results suggest that regulation of the extracellular collagen matrix might be one of the therapeutic targets in patients with HCM.

A novel cardiac myosin-binding protein C S297X mutation in hypertrophic cardiomyopathy.

BACKGROUND: Mutations in the cardiac myosin-binding protein C gene (MYBPC3) have been reported to be associated with delayed expression of hypertrophic cardiomyopathy (HCM) and a relatively good prognosis. PURPOSE: The aim of this study was to evaluate clinical manifestations in patients with familial HCM caused by a novel nonsense mutation, S297X, in MYBPC3. METHODS: We analyzed the sarcomere protein genes in 93 probands with HCM. RESULTS: The nonsense mutation S297X in MYBPC3 was present in nine subjects from two unrelated families. Eight of those nine subjects with this mutation were found to be phenotype-positive and the remaining individual was not affected phenotypically. The age range at diagnosis was 9-75 years. There was no family history of sudden death in either family. At presentation, there were various left ventricular hypertrophy (LVH) patterns, including Maron type III hypertrophy from the LV base to apex, hypertrophy confined to the anterolateral wall at the basal LV wall. Two patients showed a significant LV outflow tract gradient and one patient showed intra-right-ventricular obstruction. During follow-up, one patient was repeatedly hospitalized for the treatment of heart failure after development of paroxysmal atrial fibrillation at the age of 86 years and the remaining eight subjects were in relatively stable condition and did not require hospitalization for the treatment of HCM-related events. CONCLUSION: The novel mutation S297X in MYBPC3 causes HCM in a broad range of ages and heterogeneous clinical manifestations, though the clinical course in patients with this mutation seems to be benign.

Hemolytic anemia in a patient with hypertrophic obstructive cardiomyopathy.

A 66-year-old woman was referred for further evaluation and treatment of normocytic and normochromic anemia with hemoglobin level of 8.6 g/dL. A peripheral blood smear showed fragmented erythrocytes. The patient was then referred to the department of cardiology because of systolic murmur, ECG abnormality, and red cell fragmentation. Transthoracic echocardiography revealed hypertrophic cardiomyopathy with particularly increased interventricular septal thickness of 24 mm and a hyperkinetic wall motion, resulting in marked obstruction to left ventricular outflow tract (pressure gradient of 200 mmHg). Mitral regurgitation due to systolic anterior motion of the mitral valve leaflets was also seen. The cause of anemia was thought to be mechanical intravascular hemolysis due to left ventricular outflow tract obstruction and mitral regurgitation. She was treated with atenolol and the class Ia antiarrhythmic drug cibenzoline to relieve the outflow tract obstruction, and the pressure gradient was reduced to 70 mmHg. After 3 months of treatment, her hemoglobin level had increased to 11.4 g/dL without additional treatment for anemia.

Plasma adiponectin levels and left ventricular remodeling in hypertrophic cardiomyopathy.

Adiponectin, which is an adipose-derived protein with antiatherosclerogenic activities, has been reported to be elevated in patients with heart failure. However, there are no reports on the significance of adiponectin in patients with hypertrophic cardiomyopathy (HCM). The purpose of this study was to elucidate the clinical significance of plasma adiponectin levels in HCM patients. Clinical characteristics, echocardiographic parameters, and levels of plasma B-type natriuretic peptide (BNP) and adiponectin were evaluated in 106 HCM patients. The plasma adiponectin levels were 10.8 +/- 6.3 (range, 2.7-37.3) microg/mL. Plasma adiponectin levels were positively related to age and inversely related to body mass index (BMI). Among echocardiographic parameters, % fractional shortening (r = -0.20, P = 0.03) and maximum LV wall thickness (r = -0.23, P = 0.02) were inversely related to plasma adiponectin levels. A significant correlation between plasma adiponectin levels and BNP levels was also observed (r = 0.27, P = 0.005). In multivariate analysis, BMI, % fractional shortening, and plasma BNP levels were independent predictors of plasma adiponectin levels. Plasma adiponectin levels are associated with impaired LV systolic function in HCM patients, but not with the LV outflow gradient. Together with BNP, adiponectin can be a useful biomarker for assessing disease severity in HCM patients.

Serum cardiac troponin I is related to increased left ventricular wall thickness, left ventricular dysfunction, and male gender in hypertrophic cardiomyopathy.

BACKGROUND: Serum cardiac troponin I (cTnI) is a sensitive and specific marker of myocardial injury. However, a systematic evaluation of cTnI in hypertrophic cardiomyopathy (HCM) patients has not been performed. HYPOTHESIS: The purpose of this study is to evaluate cTnI and determine its relationship to clinical features in HCM. METHODS: We studied serum cTnI in 162 consecutive HCM patients. RESULTS: Serum cTnI ranged from 0.01 to 0.83 ng/mL (mean, 0.068 +/- 0.100 ng/mL) and was higher in male patients (P < .001), those with atrial fibrillation (P = .033), and left ventricular (LV) systolic dysfunction (P = .046). Serum cTnI values were also correlated with maximum LV wall thickness (r = 0.30, P < .001), LV end-systolic diameter (r = 0.20, P = .012), and E/Ea (peak early transmitral filling velocity/early diastolic mitral annulus velocity; r = 0.24, P = .004). Serum cTnI levels were not significantly different among New York Heart Association (NYHA) functional class and there was no difference between patients with or without LV outflow tract obstruction; although B-type natriuretic peptide (BNP) levels showed significant difference in those variables. Serum cTnI had very weak correlation with BNP values (r = 0.18, P = .023). Multivariate analysis revealed an independent relationship between cTnI and maximum LV wall thickness, E/Ea, and male gender. CONCLUSIONS: In patients with HCM, serum cTnI was associated with important clinical indices such as maximum LV wall thickness, LV dysfunction, and male gender. Serum cTnI seemed to have clinical significance different from that of BNP and may not be reflecting cardiac load but the LV remodeling process in HCM.

Hypertrophic cardiomyopathy in the elderly.

Hypertrophic cardiomyopathy (HCM) is a relatively common genetic cardiac disorder with heterogeneous morphological, functional and clinical features. Although the risk of sudden death and incapacitating symptoms in young patients has been focused upon, the disease has been found with increasing frequency in elderly patients. However, there have been few studies on clinical features of HCM in the elderly. We established a cardiomyopathy registration study in Kochi Prefecture, which is one of the most aged communities in Japan, to provide detailed descriptions of the clinical features of HCM in a community-based patient cohort. The unselected regional HCM population consisted largely of elderly patients (70% of the study cohort being >or=60 years of age at registration), although HCM has been regarded largely as a disease of the young. Cardiac hypertrophy that becomes clinically apparent late in life can be a genetic disorder, and mutations in the cardiac myosin-binding protein C gene are the most common cause of late-onset or elderly HCM. In the morphological features, sarcomere gene defects seem to have a predilection for a crescent-shaped left ventricular cavity with reversed septal curvature even in elderly patients, although an ovoid left ventricular shape was frequently seen in elderly patients in previous clinical studies on morphological characteristics of HCM. In middle-aged or elderly patients with HCM, heart failure and embolic events, which were strongly associated with atrial fibrillation, were very important. It is important to manage HCM patients from the standpoint of longitudinal evolution in order to prevent those clinical complications.