A recent analysis of over 4500 cardiac surgical patients at the Royal Infirmary of Edinburgh
has confirmed that acute kidney injury (AKI) is not only a relatively common post-operative
complication but is associated with prolonged hospital stay, and increased risk of death.
There is currently no specific therapy available except supportive care.
In laboratory studies, heme arginate (HA), a drug licensed for human use, has been shown to
upregulate the anti-inflammatory enzyme hemeoxygenase-1 (HO-1) and protect aged mice from
acute kidney injury.
This study will bring this research into the human arena. It will aim to evaluate the minimum
effective dose of HA and verify its safety in this specific group of patients. This will be
the next step in investigating if HA could be a potential protective treatment for reducing
AKI in patients about to have cardiac surgery.
Patients who are due to have cardiac surgery and are aged 60 or above will be approached for
inclusion in the study. If agreeable, they will be randomly assigned to receive either HA at
a dose of 1mg/kg or 3mg/kg. There will be 10 patients in each group.
Blood tests will be taken just before the study drug is given, at 6 hours, 24 hours and 7
days post dose. These samples will be used to examine the effect of HA on HO-1 at different
doses, and will verify drug safety. Any adverse effects of the drug will be evaluated,
although HA has an excellent safety profile when used as it is currently licensed for acute
porphyria. Urine samples will also be collected to assess inflammation and quantify urinary
biomarkers of AKI. This will set the scene for a randomised clinical trial of HA in cardiac
surgical patients at high risk of AKI.