Abstract 13245: Clinical Correlates and Heritability of Cardiac Mechanics: Insights from the HyperGEN Study
Introduction: A genetic predisposition to abnormal cardiac mechanics may explain the familial predisposition to heart failure (HF). We hypothesized that indices of cardiac mechanics (speckle-tracking strain parameters and tissue velocities) are heritable traits.
Methods: We performed speckle-tracking analysis on echocardiograms and measured global longitudinal, circumferential, and radial strain (GLS, GCS, GRS), early diastolic strain rate, and e’ velocities in the HyperGEN study, a family- and population-based study of hypertension (N=2058 [54% African American (AA)]). Additive genetic heritability estimates for cardiac mechanics were calculated by maximizing the likelihood variance components in SOLAR (ver.6) adjusted for age, sex, race, height, weight, systolic blood pressure (SBP), left ventricular (LV) mass, ejection fraction, reader, image quality, and institution.
Results: Mean age was 51±14 years and HF risk factors were common: hypertension (56%), obesity (47%), and diabetes (16%). Clinical and conventional echocardiographic characteristics, including male gender, hypertension, elevated fasting glucose, higher body-mass index, and LV hypertrophy were all significantly associated with increased absolute GLS and septal e’ velocity (P<0.05). After adjustment for covariates (and correlation within the same families), genetic contributions remained significant in GLS and septal e’ velocity in all participants, a finding which persisted in race-stratified analyses (Table).
Conclusions: Echocardiographic measures of cardiac mechanics, particularly GLS and e’ velocity, are heritable traits, even after adjustment for clinical and cardiac structural factors (e.g., SBP and LV mass, respectively) that are known to be heritable and associated with cardiac mechanics. These data support the exploration of genetics of cardiac mechanics, which may provide insight into the molecular pathogenesis of LV dysfunction and HF.
Author Disclosures: S.S. Khan: None. K.A. Kim: None. J. Peng: None. F.G. Aguilar: None. S. Selvaraj: None. E.E. Martinez: None. A.S. Baldridge: None. M.R. Irvin: None. J. Sha: None. U. Broeckel: None. D.K. Arnett: None. S.J. Shah: None.
- © 2014 by American Heart Association, Inc.