Abstract 14588: Proximal Aortic Stiffness and Pulsatile Hemodynamic Load Are Associated with Impaired Left Ventricular Longitudinal Deformation in Patients with Preserved Ejection Fraction

Abstract

Objectives: Given the close coupling between left ventricle and aorta, increased proximal aortic stiffness may adversely affect cardiac performance. We investigated whether measures of proximal aortic stiffness and hemodynamic load are associated with subclinical left ventricular systolic dysfunction in patients with normal ejection fraction (EF) and without heart failure.

Methods: We performed arterial tonometry with integrated echocardiography in 190 non-Hispanic Whites from the community who belonged to hypertensive sibships and had no cardiac disease. Measures of pulsatile hemodynamic load on the left ventricle included: aortic characteristic impedance (Zc), proximal aortic compliance (PAC, determined by the Bramwell-Hill equation) and total arterial compliance (TAC, determined by the diastolic area method). Systemic vascular resistance (SVR) was used as the measure of steady hemodynamic load. Global left ventricular longitudinal, circumferential and radial systolic strain (S) and strain rate (SR) were assessed by 2D speckle tracking echocardiography. Zc, PAC and TAC were log-transformed to reduce skewness. Multivariable linear regression analyses were performed to assess the associations of Zc, PAC, TAC and SVR with longitudinal S and SR after adjustment for age, sex, BMI, renal function, hypertension, diabetes, smoking, ascending aortic diameter and EF.

Results: Mean±SD age was 66±9 years, 61% were women, 80% were hypertensive and 19% were diabetic. Zc was inversely associated with global longitudinal S (β±SE: -0.89±0.39, P=0.02) and SR (β±SE: -0.05±0.03, P=0.06) while greater PAC was associated with higher global longitudinal S (β±SE: 0.62±0.30, P=0.03) and SR (β±SE: 0.05±0.02, P=0.04). SVR and TAC were not independently associated with any of the myocardial deformation parameters. None of the hemodynamic load parameters were associated with circumferential or radial S or SR.

Conclusions: In patients without heart failure, increased proximal aortic stiffness leading to greater pulsatile load on the left ventricle is associated with subclinical impairment of longitudinal left ventricular systolic deformation. Non-longitudinal left ventricular systolic function bears no relation to measures of arterial afterload.