Aortic stiffness and diastolic flow abnormalities in end-stage renal disease assessed by magnetic resonance imaging.
BACKGROUND
Arterial stiffness is associated with adverse cardiovascular outcomes, particularly in end-stage renal disease (ESRD). One mechanism linking arterial stiffness with cardiovascular events may be the changes in pressure wave reflection on ventricular ejection and coronary perfusion during diastole. We illustrate this using MRI to describe aortic elastic properties and alterations of diastolic flow in comparison to derived central pressure characteristics.


METHODS
Ten patients with ESRD and ten control subjects were studied. Transverse images of the ascending aorta were obtained by cardiac MRI. Aortic distensibility was calculated using brachial pulse pressure. MRI flow maps were obtained from the ascending aorta and aortic pressure was calculated using SphygmoCor.


RESULTS
ESRD patients had reduced aortic distensibility compared to the controls (median 0.00464 mm Hg(-1) vs. 0.00152 mm Hg(-1), p = 0.0057). Furthermore, in diastole, normal subjects show net reversal of blood flow in the ascending aorta, with a mean of -19.6 versus +7.6 ml/min in the ESRD group; p = 0.045.


CONCLUSIONS
Using non-invasive methods we have demonstrated a marked reduction in aortic distensibility along with disturbances in aortic flow, providing insight into the pathophysiology of ventricular-vascular interaction. The normal group showed reversal of diastolic blood flow, which may have a direct relationship with coronary perfusion parameters, which was absent in the ESRD group.
Doyle
Arthur
A
Division of Cardiovascular and Medical Sciences, University of Glasgow, Western Infirmary, Glasgow, UK. arthur.doyle@gmail.com
Mark
Patrick B
PB
Johnston
Nicola
N
Foster
John
J
Connell
John M C
JM
Dargie
Henry
H
Jardine
Alan
A
Padmanabhan
Neal
N
D000328:Adult; D001011:Aorta / Q000503:physiopathology*; D001783:Blood Flow Velocity; D001794:Blood Pressure; D003198:Computer Simulation; D004548:Elasticity; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007676:Kidney Failure, Chronic / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D013314:Stress, Mechanical