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.

BackgroundThe aim of this study is to determine the test-retest reliability of the measurement of regional myocardial function by cardiovascular magnetic resonance (CMR) tagging using spatial modulation of magnetization.MethodsTwenty-five participants underwent CMR tagging twice over 12 ± 7 days. To assess the role of slice orientation on strain measurement, two healthy volunteers had a first exam, followed by image acquisition repeated with slices rotated ±15 degrees out of true short axis, followed by a second exam in the true short axis plane. To assess the role of slice location, two healthy volunteers had whole heart tagging. The harmonic phase (HARP) method was used to analyze the tagged images. Peak midwall circumferential strain (Ecc), radial strain (Err), Lambda 1, Lambda 2, and Angle α were determined in basal, mid and apical slices. LV torsion, systolic and early diastolic circumferential strain and torsion rates were also determined.ResultsLV Ecc and torsion had excellent intra-, interobserver, and inter-study intra-class correlation coefficients (ICC range, 0.7 to 0.9). Err, Lambda 1, Lambda 2 and angle had excellent intra- and interobserver ICC than inter-study ICC. Angle had least inter-study reproducibility. Torsion rates had superior intra-, interobserver, and inter-study reproducibility to strain rates. The measurements of LV Ecc were comparable in all three slices with different short axis orientations (standard deviation of mean Ecc was 0.09, 0.18 and 0.16 at basal, mid and apical slices, respectively). The mean difference in LV Ecc between slices was more pronounced in most of the basal slices compared to the rest of the heart.ConclusionsIntraobserver and interobserver reproducibility of all strain and torsion parameters was excellent. Inter-study reproducibility of CMR tagging by SPAMM varied between different parameters as described in the results above and was superior for Ecc and LV torsion. The variation in LV Ecc measurement due to altered slice orientation is negligible compared to the variation due to slice location.Trial registrationThis trial is registered as NCT00005487 at National Heart, Lung and Blood institute.

The association of longitudinal changes in LV structure and function with myocardial fibrosis is unclear. We relate temporal changes in body-size indexed LV mass (LVMi) and end-diastolic volume (EDVi), LV mass-to-volume ratio (MVR) and ejection fraction (LVEF) from cine CMR over 10 years, with replacement scar assessed from late-gadolinium enhancement, and lower post-contrast T1 times reflecting greater diffuse myocardial fibrosis measured at the end of the follow-up period. All participants (n=1813) who underwent CMR twice as part of the Multi-Ethnic Study of Atherosclerosis 10 years apart were included. Multivariable logistic and linear regression models adjusted for cardiovascular risk factors measured the association of 10-year changes in LV structure and function, with fibrosis measured at follow-up. The presence of LV scar at year-10 was cross-sectionally associated with higher LVMi (~10g/m2), higher MVR (0.1 – 0.2g/ml) but lower LVEF (~4%); and longitudinally with 3% decrease in LVEF and 0.7% greater EDVi in men over 10 years. Lower post-contrast T1 times at year-10 were associated cross-sectionally with lower LVMi (r=0.33), EDVi (r=0.25), and LVEF (in men only: r=0.14); and longitudinally with a decrease in LVMi (r=0.20) and reduction in LVEF (in men only: r=0.15). Sustained hypertension over 10 years was associated with increased LVMi, and higher diffuse and replacement fibrosis at follow-up. Over a 10-year period increased concentric hypertrophy in women and LV dilatation in men was associated with replacement fibrosis; while decreasing LVMi was associated with diffuse fibrosis. Hypertension induced remodeling was related to enhanced replacement and diffuse fibrosis as well as hypertrophy.

).q RSNA, 2014 Purpose:To investigate the association between left atrial (LA) function and left ventricular myocardial fibrosis using cardiac magnetic resonance (MR) imaging in a multi-ethnic population. Materials and Methods:For this HIPAA-compliant study, the institutional review board at each participating center approved the study protocol, and all participants provided informed consent. Of 2839 participants who had undergone cardiac MR in 2010-2012, 143 participants with myocardial scar determined with late gadolinium enhancement and 286 age-, sex-, and ethnicity-matched control participants were identified. LA volume, strain, and strain rate were analyzed by using multimodality tissue tracking from cine MR imaging. T1 mapping was applied to assess diffuse myocardial fibrosis. The association between LA parameters and myocardial fibrosis was evaluated with the Student t test and multivariable regression analysis. Results:The scar group had significantly higher minimum LA volume than the control group (mean, 22.0 6 10.5 [standard deviation] vs 19.0 6 7.8, P = .002) and lower LA ejection fraction (45.9 6 10.7 vs 51.3 6 8.7, P , .001), maximal LA strain (S max ) (25.4 6 10.7 vs 30.6 6 10.6, P , .001) and maximum LA strain rate (SR max ) (1.08 6 0.45 vs 1.29 6 0.51, P , .001), and lower absolute LA strain rate at early diastolic peak (SR E ) (20.77 6 0.42 vs 21.01 6 0.48, P , .001) and LA strain rate at atrial contraction peak (SR A ) (21.50 6 0.62 vs 21.78 6 0.69, P , .001) than the control group. T1 time 12 minutes after contrast material injection was significantly associated with S max (b coefficient = 0.043, P = .013), SR max (b coefficient = 0.0025, P = .001), SR E (b coefficient = 20.0016, P = .027), and SR A (b coefficient 20.0028, P = .01) in the regression model. T1 time 25 minutes after contrast material injection was significantly associated with SR max (b coefficient = 0.0019, P = .016) and SR A (b coefficient = 20.0022, P = .034). Conclusion:Reduced LA regional and global function are related to both replacement and diffuse myocardial fibrosis processes.Clinical trial registration no. NCT00005487q RSNA, 2014

We used contrast-enhanced cardiac magnetic resonance (CMR) to evaluate differences in myocardial fibrosis measured at the year-10 examination between participants with and without cardiovascular (CV) events accrued in a large population based study over the preceding 10-year follow-up period in this retrospective study.

SRI predicts HF and AF over an 8-year follow-up period in a large population free of known CVD, independent of established risk factors and markers of subclinical CVD.