Assessment of Cardiac Function, Microvascular Function and Cardiac Perfusion in Different Disease Stages of Hypertrophic Cardiomyopathy

Overview

Hypertrophic cardiomyopathy (HCM) is a genetic disorder characterized by asymmetric hypertrophy of the heart in absence of loading conditions like hypertension. The genetic mutation underlying HCM sets in motion a cascade of functional and metabolic changes ultimately leading to disease. HCM patients often have microvascular dysfunction and myocardial perfusion deficits, of which the aetiology has not been elucidated. Whether these changes are secondary to remodelling or primarily caused by endothelial dysfunction is unclear. As the pathomechanism of HCM is thought to be a cascade of changes, it is important to gain more insight in the perfusion and endothelial function changes throughout different stages of disease: no phenotype, mild phenotype, and advanced HCM phenotype. In this study we aim to investigate these changes in the two most common genetic mutations.

Eligibility

Inclusion Criteria:

One of below:

• MYBPC3 mutation carrier
• MYH7 mutation carrier
• Genotype-negative first degree relative of a MYBPC3 or MYH7 mutation carrier

All of the following criteria:

• For the mutation carrier group: ≥18 years old
• For the genotype-negative group: ≥30 years old

        MYBPC3 and MYH7 mutation carriers will be designated to one of three groups based on their
        maximum wall thickness, measured by echocardiography and MRI:
          -  No phenotype: MWT <12mm
          -  Mild Phenotype: MWT ≥12 until <15mm
          -  HCM phenotype: MWT ≥15mm
        Exclusion Criteria:
          -  ≥70 years old
          -  Insulin-dependent diabetes mellitus
          -  Pregnancy
          -  Smoking
          -  Claustrophobia
          -  Pacemaker/ICD
          -  Renal insufficiency <30 GFR
          -  Hypertension (systolic >140mmHg or diastolic >90mmHg)
          -  For the genotype negative group, no phenotype group, and mild phenotype group: the use
             of blood pressure medication (diuretics, beta-blockers, ACE-inhibitors, angiotensin II
             receptor blockers, calcium channel blockers, alpha blockers)
          -  For the HCM phenotype group: when it is unsafe to withhold from blood pressure
             medication (as specified above) for two days, as assessed by their own cardiologist
          -  Left ventricular outflow tract gradient > 50mmHg
          -  Aortic valve disease
          -  Left bundle branch block
          -  (History of) Obstructive coronary artery disease
          -  Chronic atrial fibrillation
          -  Hormone replacement therapy
          -  Second or third-degree AV-block, sick-sinussyndrome, prolonged QT-interval
          -  Asthma and other obstructive pulmonary diseases
          -  Previous adverse reaction to adenosine or dotarem