Circumferential ascending aortic strain and aortic stenosis.

Background Two-dimensional speckle tracking (2D-ST) echocardiography for the measurement of circumferential ascending thoracic aortic strain (CAAS) in the context of aortic stenosis (AS) is not elucidated. Purpose This study assesses the thoracic ascending aortic deformation using 2D-ST echocardiography in AS patients. Population and methods Forty-five consecutive patients with an aortic valvular area (AVA) <= 0.85 cm(2)/m(2) were included. Regarding aortic deformation, the global peak CAAS was the parameter used, and an average of six segments of arterial wall deformation was calculated. The corrected CAAS was calculated as the global CAAS/pulse pressure (PP). Aortic stiffness (beta(2)) index was assessed according to ln(P-s/P-d)/CAAS. The sample was stratified according to the stroke volume index (SVI) as: Group A (low flow, SVI <= 35 mL/m(2); n = 19) and Group B (normal flow, SVI >35 mL/m(2); n = 26). Results The mean age was 76.8 +/- 10.3 years, 53.3% were male, the mean indexed AVA was 0.43 +/- 0.15 cm(2)/m(2), and the mean CAAS was 6.3 +/- 3.0%. The CAAS was predicted by SVI (beta = 0.31, P < 0.01) and by valvulo-arterial impedance (Z(va)). The corrected CAAS was correlated with the M-mode guided aortic stiffness index (beta 1) (r = -0.39, P < 0.01), and was predicted by SVI, Z(va), and systemic arterial compliance (beta = 0.15, P < 0.01). The beta 2 index was significantly higher for the low-flow patients (16.1 +/- 4.8 vs. 9.8 +/- 5.3, P < 0.01), and was predicted by SVI (beta -0.58, P < 0.01) and PP (beta = 0.17, P < 0.01). Global CAAS was more accurate to predict low flow than Z(va), systolic function and systemic vascular resistance. Conclusion In patients with moderate-to-severe aortic stenosis, SVI and LV afterload-related variables were the most important determinants of 2S-ST global CAAS.