Angiotensin Ii contributes to arterial compliance in congestive heart failure.
Lage, Silvia G., Liliane Kopel, Caio C. J. Medeiros, Ricardo T. Carvalho, and Mark A.
Creager.
1Heart Institute, School of Medicine, University of São Paulo, São Paulo
05403«hyphen»000, Brazil; and 2Brigham and Women's Hospital, Harvard Medical
School, Boston, Massachusetts
APStracts 9:0271H, 2002.
Arterial compliance is determined by structural factors, such as collagen and elastin, and
functional factors, such as vasoactive neurohormones. To determine whether angiotensin
II contributes to decreased arterial compliance in patients with heart failure, this study
tested the hypothesis that administration of an angiotensin-converting enzyme inhibitor
improves arterial compliance. Arterial compliance and stiffness were determined by
measuring carotid artery diameter, using high-resolution duplex ultrasonography, and
blood pressure in 23 patients with heart failure secondary to idiopathic dilated
cardiomyopathy. Measurements were made before and after intravenous administration
of enalaprilat (1 mg) or vehicle. Arterial compliance was inversely related to both
baseline plasma angiotensin II (r = «minus»0.52; P = 0.015) and angiotensin-converting
enzyme concentrations (r = «minus»0.45; P = 0.041). During isobaric conditions,
enalaprilat increased carotid artery compliance from 3.0 ± 0.4 to 5.0 ± 0.4 ×
10«minus»10 N«minus»1•m4 (P = 0.001) and decreased the carotid artery stiffness index
from 17.5 ± 1.8 to 10.1 ± 0.6 units (P = 0.001), whereas the vehicle had no effect. Thus
angiotensin II is associated with reduced carotid arterial compliance in patients with
congestive heart failure, and angiotensin-converting enzyme inhibition improves arterial
elastic properties. This favorable effect on the pulsatile component of afterload may
contribute to the improvement in left ventricular performance that occurs in patients with
heart failure treated with angiotensin-converting enzyme inhibitors.
Received 18 September 2001; accepted in final form 20 May 2002
APS Manuscript Number H820-1.
Article publication pending Am J Physiol Heart Circ Physiol
ISSN 1080-4757 Copyright 2002 The American Physiological Society.
Published in APStracts on 17 June 2002