http://www.clinicaltrials.gov. Unique identifier: NCT00005487.

Background This study sought to assess cross-sectional associations of aortic stiffness assessed by magnetic resonance imaging (MRI) with left ventricular (LV) remodeling and myocardial deformation in the Multi-Ethnic Study of Atherosclerosis (MESA). Methods and Results Aortic arch pulse wave velocity (PWV) was measured with phase contrast cine MRI. LV circumferential strain (Ecc), torsion, and early diastolic strain rate (EDSR) were determined by tagged MRI. Multivariable linear regression models were used to adjust for demographics and cardiovascular risk factors. Of 2093 participants, multivariable linear regression models demonstrated that higher arch PWV was associated with higher LV mass index (B=0.53 per 1 SD increase for log-transformed PWV, p<0.05) and LV mass to volume ratio (LVMVR) (B=0.015, p<0.01), impaired LV ejection fraction (LVEF) (B=−0.84, p<0.001), Ecc (B=0.55, p<0.001), torsion (B=−0.11, p<0.001), and EDSR (B=−0.003, p<0.05). In sex stratified analysis, higher arch PWV was associated with higher MVR (B=0.02, p<0.05), impaired Ecc (B=0.60, p<0.001) and LVEF (B=−0.45, p<0.05), but with maintained torsion in women, whereas higher PWV was associated with impaired Ecc (B=0.49, p<0.001) and LVEF (B=−1.21, p<0.001) with lower torsion (B=−0.17, p<0.001) in men. Conclusions Higher arch PWV is associated with LV remodeling and reduced LV systolic and diastolic function in a large multi-ethnic population. Greater aortic arch stiffness is associated with concentric LV remodeling, relatively preserved LVEF with maintained torsion in women, whereas greater aortic arch stiffness is associated with greater LV dysfunction demonstrated as impaired Ecc, torsion and LVEF with less concentric LV remodeling in men.

Background Tagged cardiac magnetic resonance (CMR) provides detailed information on regional myocardial function and mechanical behavior. T1 mapping by CMR allows non-invasive quantification of myocardial extracellular expansion (ECE) which has been related to interstitial fibrosis in previous clinical and sub-clinical studies. We assessed gender associated differences in the relation of ECE to LV remodeling and myocardial systolic and diastolic deformation in a large community based multi-ethnic population. Methods and Results Mid-ventricular mid-wall peak circumferential shortening and early diastolic strain rate (EDSR); LV torsion and torsional recoil rate were determined using CMR tagging. Mid ventricular short axis T1 maps were acquired in the same examination pre and post-contrast injection using Modified Look-Locker Inversion Recovery sequence (MOLLI). Multivariable linear regression (B= estimated regression coefficient) was used to adjust for risk factors and sub-clinical disease measures. Of 1230 participants, 114 participants had visible myocardial scar by late gadolinium enhancement. Participants without visible myocardial scar (n=1116) had no previous history of clinical events. In the latter group, multivariable linear regression demonstrated that lower post-contrast T1 times, reflecting greater ECE were associated with lower circumferential shortening (B=−0.1, p=0.0001), lower end diastolic volume index (LVEDVi) (B=0.6, p=0.0001) and lower LV end diastolic mass index (LVMi) (B=0.4, p=0.0001). In addition, lower post-contrast T1 times were associated with lower EDSR (B=0.01, p=0.03) in women only; and lower LV torsion (B=0.005, p=0.03) a lower LV ejection fraction (B=0.2, p=0.01) in men only. Conclusions Greater ECE is associated with reduced LVEDVi and LVMi in a large multi-ethnic population without history of previous cardiovascular events. In addition, greater ECE is associated with reduced circumferential shortening, lower EDSR, and a preserved ejection fraction in women; while in men, greater ECE is associated with greater LV dysfunction manifested as reduced circumferential shortening, reduced LV Torsion and reduced ejection fraction.