Biomechanical properties of the ascending aorta in patients with arterial hypertension by velocity vector imaging

Aortic stiffness is an important risk factor for cardiovascular events and morbidity. Increased aortic stiffness is associated with an increase in cardiac and vascular hypertension-related organ damage. To evaluate the biomechanical properties of the ascending aorta (AA) in patients with arterial hypertension (AH) by velocity vector imaging (VVI). Ninety-five patients with AH and 53 normal healthy control participants were prospectively enrolled. AA biomechanical properties, i.e., ascending aortic global longitudinal strain (ALS), ascending aortic global circumferential strain (ACS), and fractional area change (FAC), were evaluated by VVI. Relative wall thickness (RWT) and left ventricular mass (LVM) were calculated. Pulsed Doppler early transmitral peak flow velocity (E), early diastolic mitral annular velocity (e'), left ventricular global longitudinal strain (GLS), distensibility (D) and stiffness index (SI) of AA were also obtained. The ALS, ACS and FAC were significantly lower in the AH patients, especially in those with ascending aorta dilatation (AAD), than in the normal healthy control subjects. The patients with AAD had a higher E/e' ratio, RWT, LVM and SI and a lower GLS and D than patients without AAD and normal healthy volunteers (p < 0.05). There were significant associations between biomechanical properties and D, SI, E/e' and GLS (ALS and D: r = 0.606, ALS and SI: r = - 0.645, ALS and E/e': r = - 0.489, ALS and GLS: r = 0.466, ACS and D: r = 0.564, ACS and SI: r = - 0.567, ACS and E/e': r = - 0.313, ACS and GLS: r = 0.320, FAC and D: r = 0.649, FAC and SI: r = - 0.601, FAC and E/e': r = - 0.504, FAC and GLS: r = 0.524, respectively, p < 0.05). The biomechanical properties of AA were impaired in patients with AH, especially patients with ascending aorta dilatation. Hypertension is associated with a high prevalence of diastolic and systolic dysfunction and increased arterial stiffness. Further study is needed to evaluate the clinical application of AA biomechanical properties by VVI.

Evaluation of Ascending Aortic Longitudinal Strain Via Two-Dimensional Speckle Tracking Echocardiography in Hypertensive Patients Complicated by Type A Aortic Dissection

OBJECTIVE

To explore the value of ascending aortic longitudinal strain (LS) in identification of hypertensive (HP) patients with a high risk of type A aortic dissection (AAD).

METHODS

Total 40 primary HP patients with AAD (group C), 80 selected age- and sex-matched primary HP patients (group A, normal-sized ascending aorta (AA), n = 40; group B, dilated AA, n = 40) and 40 healthy volunteers were enrolled in this study. Brachial blood pressures were measured, and the aortic stiffness index (β) determined by M-mode analysis was calculated as a conventional parameter of arterial stiffness. The LS of the anterior and posterior ascending aortic wall (AW-LS and PW-LS) were determined.

RESULTS

Compared to the control group (34.21 ± 5.25%), the mean LS of AA in HP patients (group A 28.6 ± 5.95%; group B 23.64 ± 4.98%; group C 17.93 ± 3.96%; P < .001) were significantly reduced. Multivariate logistic regression analysis showed that the mean LS (OR 0.719, 95% CI 0.615-0.839, P < .001) and pulse pressure (PP) (OR 1.055, 95% CI 1.006-1.106, P = .028) were identified as independent predictors of AAD in HP patients. The AUC of mean LS combined with PP reached 0.926 (sensitivity, 95.0%; specificity, 82.5%), which was higher than the mean LS, PP, stiffness index, and ascending aortic diameter (AAd) separately. Besides, the AW-LS and PW-LS were negatively correlated with the AAd, stiffness index, stroke volume, systolic blood pressure, and PP, respectively (P < .001).

CONCLUSION

The LS of AA evaluated by two-dimensional speckle tracking echocardiography decreased significantly along with the expansion of aortic lumen and the occurrence of AAD in HP patients. It is also an independent predictor of AAD in HP patients.