Studying the Effectiveness of Pacemaker Therapy in Children Who Have Thickened Heart Muscle
Hypertrophic CardiomyopathyA heart condition called hypertrophic cardiomyopathy (HCM) causes abnormal thickening of the heart muscle, which obstructs the flow of blood out of the heart. The thickened muscle and the obstruction of blood flow are believed to cause chest discomfort, breathlessness, fainting, and a sensation of heart pounding. Treatment options for children with HCM include medicine, heart operation, and cardiac transplantation. However, there is no evidence that medicine prevents further thickening of heart muscle; operations carry the risk of death; and donor hearts are not always available. Several studies have shown that pacemaker treatment reduces the obstruction and improves heart complaints in patients with HCM. This study investigates further the efficacy of pacemaker treatment in children. Patients will have exercise tests after treatment with beta blocker and verapamil and will be eligible for the study if heart complaints or reduced exercise performance continue. A pacemaker that treats slow heart rhythms will be inserted. The patient will be sedated and local anesthesia will be administered to numb the area. The procedure takes about an hour. The study will last two years. Patients will be placed on one of two pacemaker programs for the first year and another the second year. At 3- and 6-month follow-up visits, a pacemaker check and echocardiogram will be performed. After 1 year, patients will be admitted to NIH for 2 to 3 days for exercise tests, echocardiogram, and cardiac catheterization. Also, the pacemaker will be changed to the second program. At 15- and 18-month follow-up visits, a pacemaker check and echocardiogram will be performed. After 2 years, patients will again be admitted for 2 to 3 days for exercise tests, echocardiogram, and cardiac catheterization. A pregnancy test will be given to females of child-bearing age before each cardiac catheterization and electrophysiology study. At the end of the study, the pacemaker will be set to the program that worked better. Risks of pacemaker insertion include lung collapse, infection, blood vessel damage, bleeding, heart attack, and death. Risks of cardiac catheterization include infection, bleeding, blood clots, abnormal heart rhythms, perforation of the heart, need for surgery, and death. However, the safety record for both these procedures at NIH has been excellent. The radiation exposure exceeds the NIH radiation guidelines for children, but this exposure in adults has not been associated with any definite adverse effects.
Study Evaluating the Pharmacokinetics of Mavacamten in Healthy Adult Chinese Subjects
Hypertrophic CardiomyopathyMavacamten is a small-molecule allosteric inhibitor of cardiac myosin that reversibly inhibits its binding to cardiac actin, thereby relieving systolic hypercontractility and improving ventricular compliance. This is an open-label, parallel-group, single-center Phase 1 clinical study. Healthy adult Chinese subjects with different genotypes will be included and administered with a single fasted oral dose of mavacamten to evaluate its PK profile. Up to 44 subjects will be enrolled in this study.
Pacemaker Therapy for Drug-refractory Symptoms in Mid-cavity Hypertrophic Cardiomyopathy
CardiomyopathyHypertrophicThe main aim of this study is to assess the acute effects of a pacemaker on reducing abnormally high intracavity pressures in the hearts of patients with mid-cavity obstructive hypertrophic cardiomyopathy (HCM). During a 12-month period of double-blinded follow-up, descriptive data will be collected on patients symptomatic and physical performance during dichotomous pacemaker settings for 6-months each (active and back-up). The statistical information collected will be used to design a much larger research trial of patient benefit.
REDWOOD-HCM: Randomized Evaluation of Dosing With CK-3773274 in HCM
Hypertrophic Cardiomyopathy (HCM)This study is being performed to understand the effect of different doses of CK-3773274 on patients with hypertrophic cardiomyopathy (HCM).
Effect of Metoprolol in Post Alcohol Septal Ablation Patients With Hypertrophic Cardiomyopathy
Hypertrophic CardiomyopathyIn this trial, the investigators will assess the effect of metoprolol in patients with hypertrophic cardiomyopathy who underwent alcohol septal ablation. The investigators will evaluate the quality of life, exercise tolerance, echocardiographic parameters and laboratory marker of heart failure and myocardial injury.
Clinical and Therapeutic Implications of Fibrosis in Hypertrophic Cardiomyopathy
Myocardial FibrosisHypertrophic CardiomyopathyHypertrophic Cardiomyopathy (HCM) is the most common genetic cardiomyopathy and remains the leading cause of sudden cardiac death in young people and an important cause of heart failure symptoms and death at any age. In HCM, pathological remodeling of the left ventricle involving myocardial fibrosis is likely a major contributor to cardiac dysfunction and also a nidus for the generation of ventricular arrhythmias. Serum markers of collagen turnover have been shown to reliably reflect the magnitude of myocardial fibrosis in a variety of cardiovascular diseases. In addition, aldosterone antagonist drugs have been shown to decrease fibrous tissue formation in the myocardium in certain pathologic cardiovascular states in which aldosterone production is increased. In HCM, aldosterone production is up-regulated and has been implicated in the formation of myocardial fibrosis. Therefore, the specific aims of this proposal are to: assess serum markers of collagen turnover at baseline and correlate these findings with a variety of clinical and morphologic disease parameters examine the effects of a 12-month treatment with the aldosterone antagonist spironolactone on magnitude of fibrosis as measured by serum markers of collagen turnover as well as changes in clinical and morphologic disease parameters. explore the effects of a 12-month treatment with aldosterone antagonist spironolactone on heart failure status, diastolic function, arrhythmic burden, and total LV mass and quantity of fibrosis by CMR. The results of this proposal will offer important insights into the clinical significance of myocardial fibrosis in this primary genetic cardiomyopathy. The demonstration that spironolactone decreases fibrosis and improves clinical course would provide the rational for a larger multicenter clinical trial evaluating this novel therapy for improving clinical outcome in patients with HCM.
Treatment of Preclinical Hypertrophic Cardiomyopathy With Diltiazem
Hypertrophic CardiomyopathyThis is a pilot clinical trial to assess whether the administration of diltiazem may be able to decrease the development or progression of hypertrophic cardiomyopathy (HCM). Diltiazem is a commonly used medication for the treatment of high blood pressure and studies on animals with HCM suggest that diltiazem decreases disease development. This study specifically targets individuals in the "prehypertrophic" phase of HCM-- those with documented sarcomere gene mutations without echocardiographic or EKG evidence of LVH, and therefore without a clinical diagnosis of HCM. The hypothesis of this study is that starting diltiazem administration early in life (in the prehypertrophic phase) will decrease the progression of HCM in individuals with sarcomere gene mutations. This will be assessed by looking at an improvement in the heart's ability to relax using echocardiography, as well as exploratory analyses of a broad range of features reflecting the heart's structure and function.
Analysis of Lumbar Spine Stenosis Specimens for Identification of Transthyretin Cardiac Amyloidosis...
Lumbar Spinal StenosisCardiac Amyloidosis5 morePrimary objective: To identify older adults with transthyretin cardiac amyloidosis (ATTR-CA) early in the course of the illness, at a time when disease modifying therapies are most effective. The specific aims of this epidemiologic investigation include: To identify subjects with previous lumbar spinal stenosis (LSS) Surgery who have evidence of transthyretin (TTR) amyloid deposits in spinal specimens and could be at risk for ATTR cardiac amyloidosis. To evaluate for ATTR-CA among those with localized TTR in the spinal tissue. The study will also explore the following: The prevalence of amyloid in lumbar spinal stenosis specimens by Congo Red staining. The prevalence of TTR deposits among subjects with amyloid as determined by mass spectrometry. Evaluation of a novel artificial intelligence technique for that can identify amyloid histologically with standard H&E staining. Difference in ATTR-CA prevalence between subjects with TTR and indeterminate amyloid deposits in subject's spine by myocardial uptake of technetium pyrophosphate scan (Tc99-PYP).
Effect of Mavacamten Treatment on Coronary Flow Reserve in oHCM
Obstructive Hypertrophic CardiomyopathyThe goal of this observational study is to measure the effect of mavacamten treatment on blood flow in the heart muscle (myocardium) in patients with obstructive hypertrophic cardiomyopathy. The main question it aims to answer is: • Does mavacamten treatment improve blood flow in the heart muscle? Participants will take mavacamten at the direction of their treating physician. Participants will complete 2 myocardial Positron Emission Tomography and Computed Tomography (PET-CT) scans. The first scan will be completed before participants start taking mavacamten. The scan will be repeated after 12 months of mavacamten treatment.
Mitral Valve in Hypertrophic Cardiomyopathy
Hypertrophic Obstructive CardiomyopathyThe purpose of the study is to assess the role of mitral valve apparatus in the development of outflow tract obstruction in patients with hypertrophic cardiomyopathy and to identify the best surgical treatment modality to relieve outflow tract obstruction in such patients