Arterial stiffness is a marker of cardiovascular damage and an independent predictor of major cardiovascular events, usually assessed via Carotid-Femoral Pulse Wave Velocity (cfPWV). The aim of this study was to test the feasibility and usefulness of aortic strain analysis using a simplified transthoracic echocardiography (TTE) speckle-tracking (ST) based method. 60 consecutive patients with normal blood pressure and aortic dimensions underwent TTE and cfPWV evaluation. Strain analysis was performed on the largest section of the ascending aorta (aA) with a dedicated software; three couples of speckles were identified within the anterior and posterior aortic wall and transverse segments connecting each couple traced. Peak ascending Aorta Strain (PaAS) was defined as the averaged peak percentage deformation of these segments during the cardiac cycle; aortic stiffness index β2 was defined as 100 × Ln(SBP/DBP)/PaAS. 17 patients were excluded for suboptimal TTE images. In the 43 analyzed individuals (male 58%, age 63 years) PaAS was 5.5 [3.7-8.6] % with excellent inter and intra observer reproducibility (ICC 95% for both). PaAS showed significant correlation with age (r = - 0.64), aA diameter (r = - 0.45), cfPWV (r = - 0.41), stroke volume (r = - 0.41) and heart rate (r = - 0.49). Age remained the only independent determinant of PaAS in a multivariate analysis. β2 (10.8 [5.9-15.0]) showed significant direct correlation with age, Pulse pressure, aA diameter and cfPWV. A simplified strain analysis of the ascending aorta is technically feasible with good reproducibility; PaAS and β2 index correlate well with established parameters of arterial stiffness and might represent a new index in evaluating vascular biomechanics.
Keywords: Arterial stiffness; Pulse wave velocity; Speckle-tracking echocardiography; Strain analysis.