MRI scans of dialyzing patients shows stress treatment puts on heart
Researchers at the University of Nottingham have carried out MRI scans on patients while they dialyze to study their heart function during treatments, and found left ventricular dysfunction and a decrease in blood flow to the small capillaries in the heart muscle in all patients.
The study aimed to investigate stress on the heart during kidney dialysis and to compare two different types of dialysis: standard hemodialysis (HD) and hemodiafiltration (HDF).
Experts from the University’s Sir Peter Mansfield Imaging Centre (SPMIC) and the Centre for Kidney Research and Innovation (CKRI) carried out MRI scans on 12 kidney dialysis patients who were each allocated to receive both standard HD and HDF in a random order.
The study found significant cardiovascular effects with both standard HD 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.
“This is the first time that MRI has been used to look at heart function while the kidney patient is actually undergoing dialysis,” said Professor of Physics, Sue Francis. “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.”
Researchers measured the volume of blood 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, and myocardial perfusion to check the efficiency of blood flow to the capillaries.
“Interestingly, we found all measures of systolic contractile function fell during both standard haemodialysis and haemodiafiltration with partial recovery after dialysis, said Professor of Medicine (Nephrology), Maarten Taal. “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.