Aortic Distensibility in Patients with Valvular Heart Disease: a Cardiovascular Magnetic Resonance Study

Aortic stenosis (AS) and mitral valve regurgitation (MR) are the most common heart valve defects that can lead to heart failure due to structural and functional changes in the heart. To date, few studies have evaluated the biomechanical changes of the heart and large vessels and their impact on morbidity and mortality for cardiovascular diseases. Study aims. To evaluate left ventricular (LV) geometry and function parameters in patients with severe AS and severe MR, as well as aortic elasticity (distensibility) using cardiac magnetic resonance (CMR) imaging, to compare with those measured in healthy individuals. Methods. The study included 82 subjects: 30 patients with severe AS, 20 patients with severe MR, and 32 healthy individuals. CMR cine images were used to analyze LV morphometric and functional parameters and to compare different study groups. All measurements were performed on three long-axis (in two-, three- and four-chamber) cine images and three short-axis cine images (basal, mid-ventricular, and the apical). Aortic distensibility was calculated using a dedicated equation after measuring the minimum and maximum cross-sectional area of the descending thoracic aorta and its absolute aortic area change. Data analysis was performed using IBM SPSS Statistics 21.0 software. Results. A comparison of the characteristics in patients with severe AS, MR, and healthy individuals showed that patients with severe AS were older; their body weight and body mass index were significantly higher; exceptional diastolic pressures in patients with MR occurred lower compared with other study groups. Comparing LV parameters between severe AS and MR groups, higher myocardial mass and its index were found in the AS group; In patients with severe MR and healthy individuals were significantly higher LV volumes, LV myocardial mass, and cardiac index, also significantly reduced myocardial deformation parameters. A comparison of aortic distensibility revealed that only the maximal descend-ing thoracic aortic cross-sectional area has a statistically significant difference in patients with severe MR and AS; severe MR with healthy individuals – only the absolute change in the descending aortic cross-sectional area differed statistically significantly; The AS group compared with healthy individuals – the absolute change in the cross-sectional area of the descending aorta and the distensibility of the aorta changes differed statistically significant-ly. Conclusions. The largest descending thoracic aortic cross-sectional area is significantly more prominent in patients with severe AS compared with severe MVI, whereas comparing the two groups of LV volumes, their indexed values, and systolic function indices (LVEF, global longitudinal and radial strain) did not differ significantly. Aortic distensibility in patients with high-grade AS and high-grade MR was not statistically significant but was significantly lower compared to healthy individuals