Decreased coronary flow reserve in haemodialysis patients.

Background: Coronary flow reserve (CFR) reflects the functional capacity of microcirculation to adapt to blood demand during increased cardiac work.

Methods: Forty-one patients who had already undergone coronary angiography were studied. They consisted of 21 haemodialysis patients with no significant left anterior descending coronary artery (LAD) stenosis and 20 non-renal failure patients without LAD stenosis. We performed transthoracic Doppler recording of diastolic coronary flow velocity in the LAD at baseline and after maximal vasodilatation by adenosine triphosphate (ATP) infusion. CFR was defined as the ratio of hyperaemic to basal averaged peak flow velocity.

Results: Although the peak coronary velocities during hyperaemia were similar between the two groups, CFR was smaller in haemodialysis (HD) patients than in control subjects (1.96 +/- 04 versus 2.3 +/- 0.5, P = 0.001) due to the higher baseline peak coronary velocities in the former.

Conclusions: The elevated baseline peak coronary velocity may be caused by cardiac hypertrophy and anaemia in HD patients.