Microstructural and Microvascular Phenotype of Sarcomere Mutation Carriers and Overt Hypertrophic Cardiomyopathy.

BACKGROUND: In hypertrophic cardiomyopathy (HCM), myocyte disarray and microvascular disease (MVD) have been implicated in adverse events, and recent evidence suggests that these may occur early. As novel therapy provides promise for disease modification, detection of phenotype development is an emerging priority. To evaluate their utility as early and disease-specific biomarkers, we measured myocardial microstructure and MVD in 3 HCM groups-overt, either genotype-positive (G+LVH+) or genotype-negative (G-LVH+), and subclinical (G+LVH-) HCM-exploring relationships with electrical changes and genetic substrate. METHODS: This was a multicenter collaboration to study 206 subjects: 101 patients with overt HCM (51 G+LVH+ and 50 G-LVH+), 77 patients with G+LVH-, and 28 matched healthy volunteers. All underwent 12-lead ECG, quantitative perfusion cardiac magnetic resonance imaging (measuring myocardial blood flow, myocardial perfusion reserve, and perfusion defects), and cardiac diffusion tensor imaging measuring fractional anisotropy (lower values expected with more disarray), mean diffusivity (reflecting myocyte packing/interstitial expansion), and second eigenvector angle (measuring sheetlet orientation). RESULTS: Compared with healthy volunteers, patients with overt HCM had evidence of altered microstructure (lower fractional anisotropy, higher mean diffusivity, and higher second eigenvector angle; all P<0.001) and MVD (lower stress myocardial blood flow and myocardial perfusion reserve; both P<0.001). Patients with G-LVH+ were similar to those with G+LVH+ but had elevated second eigenvector angle (P<0.001 after adjustment for left ventricular hypertrophy and fibrosis). In overt disease, perfusion defects were found in all G+ but not all G- patients (100% [51/51] versus 82% [41/50]; P=0.001). Patients with G+LVH- compared with healthy volunteers similarly had altered microstructure, although to a lesser extent (all diffusion tensor imaging parameters; P<0.001), and MVD (reduced stress myocardial blood flow [P=0.015] with perfusion defects in 28% versus 0 healthy volunteers [P=0.002]). Disarray and MVD were independently associated with pathological electrocardiographic abnormalities in both overt and subclinical disease after adjustment for fibrosis and left ventricular hypertrophy (overt: fractional anisotropy: odds ratio for an abnormal ECG, 3.3, P=0.01; stress myocardial blood flow: odds ratio, 2.8, P=0.015; subclinical: fractional anisotropy odds ratio, 4.0, P=0.001; myocardial perfusion reserve odds ratio, 2.2, P=0.049). CONCLUSIONS: Microstructural alteration and MVD occur in overt HCM and are different in G+ and G- patients. Both also occur in the absence of hypertrophy in sarcomeric mutation carriers, in whom changes are associated with electrocardiographic abnormalities. Measurable changes in myocardial microstructure and microvascular function are early-phenotype biomarkers in the emerging era of disease-modifying therapy.

Pre-genetics clinic resource evaluation for adults with intellectual disability: The pre-genetics clinic aid.

People with intellectual disability (PWID) consistently identify the importance of health service information that is accessible and relevant. Resources tailored to the information and support needs of PWID can facilitate inclusivity in their health care (including access to genomic medicine) and improve healthcare outcomes. Despite the fact that PWID are commonly referred to genetics services, there is a lack of appropriate resources to help them prepare for their appointments. We therefore aimed to evaluate the feasibility and acceptability of a booklet for PWID to read with their carers prior to their genetics appointment, to help them prepare for what they may experience. With input from Easy to Read experts and PWID who were members of the New South Wales (NSW) Council for Intellectual Disability, the information booklet 'Getting ready for your visit to the genetics clinic' was produced. Australian healthcare professionals (HCP) familiar with clinical genetics services were invited to complete an anonymous online survey designed to assess perceived relevance, readability, and utility of the resource. Recruitment of HCPs was pursued via affiliated clinical services and email distribution through clinical genetics organizations. Sixty-six HCPs completed and submitted the survey. The results demonstrated that HCPs believed the booklet represented a typical clinical genetics service appointment and that the majority would provide a copy of the resource to clients and their carers. They reported that the booklet was easy to understand and entailed appropriate content and images which were presented clearly and simply. Some minor modifications were recommended and incorporated into the resource. A model of customizable booklets such as this could be transferrable across clinical genetics services and guide development of other resources for PWID. This may help to reduce healthcare disparities, improve client satisfaction, and facilitate involvement of PWID in their own healthcare decisions.