Acute kidney injury is associated with a rise in serum uric acid during cardiovascular surgery and can cause poor blood flow to the kidneys making them vulnerable to kidney injury. We hypothesize that hyperuricemia, particularly if chronic and marked, is a risk factor for acute kidney injury. The preoperative lowering of serum uric acid will reduce the incidence of acute kidney injury following cardiovascular surgery.

The study will be a prospective, double-blind, placebo-controlled, randomized, clinical trial, initiated and implemented conjointly by the Nephrology and Cardiovascular Surgery Departments at Shands Hospital at the University of Florida in Gainesville, FL. We propose to study whether lowering uric acid provides significant renal and cardiovascular protection in subjects undergoing cardiovascular surgery. Up to 30 patients presenting for elective or urgent cardiovascular surgery with uric acid level > 6.5 mg/dl and estimated glomerular filtration of 30 - 60 ml/min will be included in the study. Patients recruitment will continue until up to 30 patients have completed the study, taking into account expected patient loss due to withdrawal of consent, incomplete study and other reasons.

Patients will be randomized to a control group or rasburicase group. Rasburicase or identical placebo will be administered to each group after randomization. A selected number of patients may undergo additional testing for mechanistic (non-clinical) secondary endpoints.

Inclusion Criteria:

1. Age 18 years or older, and
2. Undergoing elective cardiothoracic surgery(s), alone or in combination with other procedures/surgery(s): thoracic aortic aneurysm, cardiac valves, coronary artery bypass grafting, abdominal thoracic aneurysm, other CV surgery, and
3. Preoperative serum uric acid > 6.5 mg/dL, and
4. Preoperative estimated glomerular filtration rate of >30ml/min/1.73m2 or higher, but less than 60ml/min/1.73m2

Exclusion Criteria:

1. Prior history of allergy/adverse reaction to Rasburicase
2. History of any organ transplant
3. Preoperative intra-aortic balloon pump (IABP)
4. Known glucose 6-phosphate dehydrogenase (G6PD) deficiency
5. Current use of natriuretic peptides

No Adverse Events occurred during the 15 months when data was collected.

The limitation of the pilot study is that it was not powered to provide definite answers, an inherent limitation attributed to the absence of similar studies.