People with kidney failure need regular dialysis to remove fluid and
waste products from their blood, but this process can cause falls in
blood pressure and reduced blood flow to the heart. Over time this can
cause long-term damage to the heart.
Experts in magnetic resonance imaging (MRI) and kidney disease have
carried out the first ever scans to study the heart function of kidney
patients while they are having dialysis treatment.
‘All measures of systolic contractile function fell during both standard hemodialysis and hemodiafiltration with partial recovery after dialysis.’
Research at The University of Nottingham was undertaken to
investigate stress on the heart during kidney dialysis and to compare
two different types of dialysis in this regard: standard haemodialysis
(HD) and hemodiafiltration (HDF), a process that removes more fluid
during treatment but with additional replacement fluid being given to
Experts from the University's Sir Peter Mansfield Imaging Center
(SPMIC) and the Center for Kidney Research and Innovation (CKRI) carried
out MRI scans on 12 kidney dialysis patients who were each allocated to
receive both standard haemodialysis (HD) and HDF in a random order.
The study found significant cardiovascular effects with both
standard hemodialysis and HDF, but no differences between the two.
Results demonstrate that cardiac MRI can be a vital tool for evaluating
future improvements to dialysis treatment.
Professor of Physics, Sue Francis, said, "This is the first time
that MRI has been used to look at heart function while the kidney
patient is actually undergoing dialysis. There were several hurdles to
overcome to achieve this. We had to set up a dialysis machine in our MRI
research center, change the metal needles that go into the patient to
non-magnetic silicone ones, extend and insulate the lines that connect
the patient to the dialysis machine and position the equipment using our
knowledge of the magnetic fields in the MRI unit."
Professor of Medicine (Nephrology), Maarten Taal, said, "Using this
unique set-up we were able to monitor multiple cardiovascular
measurements while dialysis was taking place in the patients. We
measured how many liters of blood were pumped per minute by the left
ventricle of the heart, how well the heart muscle was able to contract,
blood flow in the coronary artery which supplies the heart muscle and
myocardial perfusion to check the efficiency of blood flow to the
capillaries or tiny blood vessels in the heart muscle."
"Interestingly, we found all measures of systolic contractile
function fell during both standard hemodialysis and hemodiafiltration
with partial recovery after dialysis. All patients showed some degree of
left ventricular dysfunction and blood flow to the small capillaries in
the heart muscle decreased significantly during both types of
treatment. Our observations confirm the need for interventions to reduce
the negative impact of dialysis on the heart."
Having successfully tested this method, the research team is now
aiming to test the effects of other dialysis treatments using MRI.
Intradialytic Cardiac Magnetic Resonance Imaging to Assess
Cardiovascular Responses in a Short-Term Trial of Hemodiafiltration and
Hemodialysis is published in the Journal of the American Society of Nephrology