Multi-Ethnic Study of Atherosclerosis: Association between Left Atrial Function Using Tissue Tracking from Cine MR Imaging and Myocardial Fibrosis

Abstract

).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

Hypertensive patients with left ventricular hypertrophy have global left atrial dysfunction and impaired atrio-ventricular coupling

“…Elevated LV filling pressures related to LV diastolic dysfunction have been considered to be the main underlying mechanism of LA dysfunction in patient with HTN and LV hypertrophy [20,21]. Several recent findings suggest that LA myocardial fibrosis may also play a role [22,23], and that the degree of elevated LV filling pressure is only modestly correlated to LA reservoir function, as in our study. The noninvasively assessed LA stiffness index was indeed significantly greater in our HTN group than in controls, suggesting lower compliance and lower active LA relaxation.…”

Association of Left Atrial Function and Left Atrial Enhancement in Patients With Atrial Fibrillation

“…Multimodality Tissue Tracking software (MTT; version 6.0, Toshiba, Japan) was used to measure phasic LA volumes, strain and strain rate from 4-chamber and 2-chamber cine CMR images 18, 19 . An experienced operator contoured endocardial and epicardial LA borders in 2- and 4- chamber cine CMR images, taking care to exclude the pulmonary veins and the LA appendage.…”

“…In contrast, myocardial motion can be accurately tracked with CMR due to its ability to accurately define endocardial and epicardial borders 14 . CMR-feature tracking, a novel post–processing technique which tracks myocardial motion using cine CMR images, has recently been developed 15-19 . In this study, we sought to examine the association of LA fibrosis measured with LGE-CMR with phasic LA remodeling measured with feature-tracking CMR in patients with AF.…”

Cardiovascular Magnetic Resonance Myocardial Feature Tracking

“…Close correlation of impaired LA function and replacement and diffuse myocardial fibrosis as determined by late gadolinium enhancement and T1-mapping has been demonstrated. 42 It is interesting to speculate whether increased LV stiffness is associated with diffuse myocardial fibrosis and the resulting impaired atrial performance could be a sensitive marker of early diastolic impairment. Our group has identified different patterns of LA impairment associated with different diseases.…”