Assessment of ascending aorta wall stiffness in hypertensive patients by tissue Doppler imaging and strain Doppler echocardiography

Background Aortic stiffness may be associated with an increased incidence of cardiovascular events and has been reported to be related to arterial wall motion velocities as measured by tissue Doppler imaging. Objective To investigate the potential clinical application of tissue Doppler imaging (TDI) for assessment of aortic function parameters in healthy and hypertensive adults. Methods 110 hypertensive and 80 healthy adults were examined. Pulse wave velocity (PWV) and augmentation index (Aix) were measured as standard parameters of arterial stiffness by an oscillometric system. Aortic M-mode and TDI parameters were measured. Aortic distensibility (D) and aortic stiffness index (SI) were calculated using accepted formulae. Anterior wall aortic expansion velocity (S(Ao)), acceleration time (AT(Ao)), early (E(Ao)) and late (A(Ao)) diastolic retraction velocity and peak systolic radial strain (epsilon(Ao)) were determined. Comprehensive echocardiography was performed for the assessment of left ventricular (LV) systolic/diastolic function. Results S(Ao), E(Ao) and e(Ao) were significantly lower in hypertensive subjects (p<.001, p<.001, and p<.0001, respectively). Reduced D (p<.05 vs controls) and increased PWV (p<.05 vs controls) and SI (p<.01 vs controls) were consistent with evidence of increased aortic stiffness in both male and female hypertensive patients. PWV and Aix increased and D decreased with increasing age or systolic blood pressure. Multivariate analysis showed epsilon(Ao) to be independently related (R2 = 0.63) to pulse pressure, LV mass index and diastolic function. Conclusion Ascending aorta TDI provides wall velocity and strain data differentiating hypertensive from healthy adults and reflecting aortic compliance changes related to age and sex and LV diastolic function.