The differential meaning of LV and LA strains in aortic valve stenosis: A feature tracking MRI study

Feature tracking (FT) is an emerging approach for the evaluation of both left atrium (LA) and left ventricular (LV) myocardial strain from cine MRI. We aimed to: 1) perform a simultaneous evaluation of LA and LV strain in patients with aortic valve stenosis (A VS) and 2) evaluate associations of LA strain measurements with LV remodeling (LVmass/LVend-diastolic volume) and strain. We studied 55 patients (34 AVS:71±11 years, 21 controls :66±9 years) with preserved LV ejection fraction (LVEF). FT was applied to cine MRI to extract LV longitudinal, circumferential and radial strain as well as LA longitudinal strain and radial motion fraction for the reservoir, conduit and LA contraction phases. All LV strains decreased significantly in AVS. Similarly, all LA indices showed a decreasing trend in AVS patients as compared to controls. While reservoir and conduit phases LA strains were significantly associated with LV remodeling and strain (r>0.42), lower correlations were found for comparisons with LA contraction phase strains (r<;0.28). Such low association might be explained by the found bi-phasic distribution of contraction phase strains with LV remodeling quartiles. LA contraction strain seems to be a marker of intrinsic LA alteration that could be potentially used to predict progression towards atrial fibrillation in AVS patients.