Ultrasonic Assessment of Myocardial Microstructure in Hypertrophic Cardiomyopathy Sarcomere Mutation Carriers With and Without Left Ventricular Hypertrophy.

Abstract

BACKGROUND:

The noninvasive assessment of altered myocardium in patients with genetic mutations that are associated with hypertrophic cardiomyopathy (HCM) remains challenging. In this pilot study, we evaluated whether a novel echocardiography-based assessment of myocardial microstructure, the signal intensity coefficient (SIC), could detect tissue-level alterations in HCM sarcomere mutation carriers with and without left ventricular hypertrophy.

METHODS AND RESULTS:

We studied 3 groups of genotyped individuals: sarcomere mutation carriers with left ventricular hypertrophy (clinical HCM; n=36), mutation carriers with normal left ventricular wall thickness (subclinical HCM; n=28), and healthy controls (n=10). We compared measurements of echocardiographic SIC with validated assessments of cardiac microstructural alteration, including cardiac magnetic resonance measures of interstitial fibrosis (extracellular volume fraction), as well as serum biomarkers (NTproBNP, hs-cTnI, and PICP). In age-, sex-, and familial relation-adjusted analyses, the SIC was quantitatively different across subjects with overt HCM, subclinical HCM, and healthy controls (P<0.001). Compared with controls, the SIC was 61% higher in overt HCM and 47% higher in subclinical HCM (P<0.001 for both). The SIC was significantly correlated with extracellular volume (r=0.72; P<0.01), with left ventricular mass and E' velocity (r=0.45, -0.60, respectively; P<0.01 for both), and with serum NTproBNP levels (r=0.36; P<0.001).

CONCLUSIONS:

Our findings suggest that the SIC could serve as a noninvasive quantitative tool for assessing altered myocardial tissue characteristics in patients with genetic mutations associated with HCM. Further studies are needed to determine whether the SIC could be used to identify subclinical changes in patients at risk for HCM and to evaluate the effects of interventions.

• Authors: Pranoti Hiremath, Patrick R Lawler, Jennifer E Ho, Andrew W Correia, Siddique A Abbasi, Raymond Y Kwong, Michael Jerosch-Herold, Carolyn Y Ho, Susan Cheng
• Journal: Circulation. Heart failure (Circ Heart Fail) Vol. 9 Issue 9 (09 2016) ISSN: 1941-3297 [Electronic] United States
• PMID: 27623770 (Publication Type: Comparative Study, Evaluation Study, Journal Article)
• Copyright: © 2016 American Heart Association, Inc.

Chemical References

• Biomarkers

Topics

• Adult
• Asymptomatic Diseases
• Biomarkers (blood)
• Cardiomyopathy, Hypertrophic (blood, diagnostic imaging, genetics, pathology)
• Case-Control Studies
• Cross-Sectional Studies
• Echocardiography, Doppler (methods)
• Female
• Genetic Predisposition to Disease
• Humans
• Hypertrophy, Left Ventricular (blood, diagnostic imaging, genetics, pathology)
• Image Processing, Computer-Assisted
• Magnetic Resonance Imaging, Cine
• Male
• Mutation
• Myocardium (pathology)
• Phenotype
• Pilot Projects
• Predictive Value of Tests
• Prognosis
• Reproducibility of Results
• Young Adult