Systemic Angiotensinogen Concentrations Are Independently Associated with Left Ventricular Diastolic Function in a Community Sample

Abstract

BACKGROUND Left ventricular (LV) diastolic dysfunction characterizes heart failure with a preserved ejection fraction. Although it is recognized that the renin-angiotensin-aldosterone system (RAAS) decreases LV diastolic function, whether systemic angiotensinogen (AGT) contributes to these effects is uncertain. Hence, the aim was to determine the relationship between systemic AGT concentrations and LV diastolic function. METHODS LV diastolic function was determined from the mean of the lateral and septal wall myocardial tissue lengthening at the mitral annulus (average e') and from the ratio of early transmitral blood flow velocity (E) to average e' (E/e') in 445 Black African participants from a community sample. RESULTS In multivariate regression models with adjustments for age, sex, waist circumference diabetes mellitus, alcohol and tobacco use, hypertension treatment, systolic blood pressure (BP), and relative wall thickness, the square root of serum AGT concentrations was independently associated with E/e' (partial r (95% confidence interval [CI]) = 0.11 (0.02-0.21), P = 0.04), but not with average e' (partial r (95% CI) = -0.06 (-0.15 to 0.04), P = 0.25). There was no association between plasma renin concentrations and markers of diastolic function (all P > 0.05). CONCLUSION Circulating AGT concentrations are associated with LV diastolic function beyond BP and other confounders in an African population. Hence, through circulating AGT, the systemic RAAS may play an important role in contributing to LV diastolic function in Black Africans.