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.