Non-invasive assessment of myocardial stiffness by the two-dimensional shear wave elastography ultrasound technique in patients with amyloidosis and Fabry disease

Abstract Background Cardiac amyloidosis and Fabry disease are cardiomyopathies that evolve with structural alteration of the ventricular walls, diastolic dysfunction and heart failure. Diastolic dysfunction encompass myocardial stiffness and impaired relaxation. Cardiac elastography has been proposed as a diagnostic modality for the non-invasive assessment of myocardial stiffness. Purpose The aim of this study was to investigate if myocardial shear wave elastography could assess myocardial stiffness in Healthy volunteers, Fabry disease and variant transthyretin amyloidosis (ATTRv) patients with cardiac involvement and correlate with other complementary imaging and laboratory tests (electrocardiogram, 2D echocardiogram, troponin and BNP) and with the 6-minute walk test. Methods We prospectively included 60 adults: 20 patients with Fabry disease, 20 patients with ATTRv and 20 patients as control group. Echocardiography, electrocardiogram and laboratory evaluations were performed. Elastography assessment of myocardial stiffness was performed using an ultrasound equipment with a multifrequency convex transducer, under specific adjustment of the equipment for performing myocardial elastography. Results Myocardial Stiffness was significantly higher in Cardiac Amyloidosis patients than in healthy volunteers in anteroseptal basal segment (ASB) (PLAX 6.95 ± 1.4 kPa vs. 5.45 ± 1.1 kPa, respectively, p=0.02; PSAX 6.85 ± 1.4 kPa vs. 5.4 ± 1.2 kPa, respectively, p=0.02) and right ventricle (RV) (5.9 ± 2.6 kPa vs. 4.0 ± 0.7 kPa, respectively, p=0.003) and no difference in anteroseptal mid and septal apical. Statistically difference between Fabry Disease patients and Cardiac Amyloidosis group was found in right ventricle (5.9 ± 2.6 kPa vs. 4.4 ± 1.0 kPa, respectively, p=0.01). Conclusion Myocardial Stiffness was significantly higher in patients with Cardiac Amyloidosis compared with healthy volunteers in anteroseptal basal and right ventricle, but with no difference in anteroseptal mid and septal apical. Cardiac Amyloidosis myocardial stiffness was statistically higher in right ventricle compared with Fabry Disease group.