Identifying predictors of shear wave speed in cardiac shear wave elastography using multivariable analysis

Cardiac shear wave elastography (SWE) utilizes high-frame-rate ultrasound imaging to measure shear wave (SW) velocity propagation, providing an index of myocardial stiffness. While SW velocity reflects stiffness, other contributing factors remain unclear. We retrospectively analyzed 439 subjects (age: 54 ± 22 years), including healthy volunteers and patients with ten different cardiovascular and systemic conditions. Standard echocardiography and SWE in the parasternal long-axis view were performed. SWs were visualized using tissue acceleration spatiotemporal maps, and wave propagation velocities were calculated from anatomical M-mode slopes. Associations between SW speed and clinical or echocardiographic variables were assessed using univariable and multivariable regression. Multivariable analysis identified associations with presence of pathology, left atrial volume index (LAVi), e′ average, LV mass, and body mass index (BMI), mentioned in order of importance (R = 0.67). These findings indicate that SW speed, in a large, heterogeneous cohort, is influenced by both structural remodeling and LV filling pressures. This offers new insights into the interpretation of SWE measurements across diverse populations, highlighting the need to account for these factors when assessing myocardial stiffness.