Multi-parametric speckle tracking analyses to characterize cardiac amyloidosis: a comparative study of systolic left ventricular longitudinal myocardial mechanics

Cardiac amyloidosis (CAM), the most common cardiac storage disease is associated with significant changes in left-ventricular (LV) morphology and function. To gain particular insights into LV systolic longitudinal myocardial mechanics we investigated seven parameters derived by speckle-tracking-echocardiography (STE) in patients with confirmed CAM (n = 59). The results were compared with those of individuals with healthy heart (n = 150) and another primary myocardial disease with also thickened myocardium and severe diastolic and systolic LV-dysfunction (symptomatic LV-non-compaction-cardiomyopathy, LV-NC, n = 30). In addition to standard echocardiographical measures, the STE-derived data were evaluated and documented utilizing polar-diagrams to obtain overviews of longitudinal myocardial mechanics of the entire LV. Compared with healthy individuals, patients with CAM and LV-NC showed significantly reduced LV-ejection-fraction (EF), global longitudinal systolic peak-strain, strain-rate, and displacement. Pre-systolic stretch-index, post-systolic index, and the EF/global peak-longitudinal-strain-ratio (EF/S) were increased. In contrast to healthy-hearts and the LV-NC group only patients with CAM demonstrated significantly reduced time-to-peak systolic longitudinal strain and time-to-peak strain-rate. Although the level of the segmental values in longitudinal mechanics was significantly different between the groups, comparable intraventricular baso-apical parameter-gradients were found for systolic longitudinal peak-strain and strain-rate, pre-systolic-stretch-index, post-systolic-index, and peak systolic displacement. Compared to ATTR-amyloidosis (ATTR-CAM), patients with AL-amyloidosis (AL-CAM) demonstrated significantly lower end-diastolic and end-systolic LV-volumes, LV-mass-indices, relative apical strain, time-to-peak systolic longitudinal strain, and time-to-peak longitudinal strain-rate. CAM and LV-NC demonstrated altered myocardial mechanics with significantly different STE-derived echocardiographical parameters. ATTR-amyloidosis and AL-amyloidosis had at least significantly different time-to-peak strain, time-to-peak strain-rate and relative apical sparing values.