Associations of Alterations in Pulsatile Arterial Load With Left Ventricular Longitudinal Strain

Abstract

Background: Increased arterial stiffness leads to increased pulsatile load on the heart. We investigated associations of components of pulsatile load with a measure of left ventricular (LV) systolic function-global longitudinal strain (GLS), in a community-based cohort ascertained based on family history of hypertension.

Methods: Arterial tonometry and echocardiography with speckle tracking were performed in 520 adults with normal LV ejection fraction (EF) (age 67±9 years, 70% hypertensive) to quantify measures of pulsatile load (characteristic aortic impedance (Zc), total arterial compliance (TAC), and augmentation index (AI)) and GLS. The associations of log-Zc, log-TAC, and AI with GLS were assessed using sex-specific z-scores for each measure of arterial load.

Results: In univariable analyses, higher Zc was associated with worse GLS (less negative) and higher TAC and AI were associated with better GLS (all P < 0.001). In a multivariable model including age, sex, heart rate (HR), LVEF, mean arterial load (systemic vascular resistance), and measures of pulsatile load, Zc remained associated with GLS (β = 0.28, P < 0.001), while the associations of TAC and AI were no longer significant (P > 0.5). Additional adjustment for cardiovascular risk factors and history of coronary heart disease and stroke did not attenuate the association of Zc with GLS; Zc, sex, HR, LVEF remained associated with GLS after stepwise elimination (all P < 0.001).

Conclusions: Greater proximal aortic stiffness, as manifested by a higher Zc, is independently associated with worse LV longitudinal function.

Keywords: aortic characteristic impedance; arterial load; arterial–ventricular interaction; blood pressure; hypertension; left ventricular deformation; left ventricular function; speckle tracking echocardiography..