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.