Effect of uric acid lowering therapy on the prevention of acute kidney injury in cardiovascular surgery

Serum uric acid (SUA) is a novel risk factor for acute kidney injury (AKI), which adversely affects renal blood flow autoregulation, glomerular filtration rate (GFR), and promotes inflammation and angiogenesis. This pilot study investigated the effect of lowering SUA therapy on AKI, by using traditional and non-traditional markers. In this prospective, double-blind, placebo-controlled, randomized pilot trial, 26 hyperuricemic patients undergoing cardiac surgery were randomized to receive rasburicase or placebo in the preoperative period. Subjects receiving rasburicase showed no difference in serum creatinine compared with the control group receiving placebo. Despite no difference in primary endpoint, the rasburicase group had less evidence of renal structural injury as reflected by urine neutrophil-associated lipocalin (uNGAL) concentrations, especially in subjects with higher SUA levels, more severe renal dysfunction (baseline GFR a parts per thousand currency sign 45 mL/min/1.73 m(2)) or heart failure (left ventricular ejection fraction a parts per thousand currency sign45 %). In this study, rasburicase showed no benefit on postoperative serum creatinine in hyperuricemic subjects undergoing cardiac surgery. However, the observation that markers of structural renal injury such as uNGAL tended to be lower in rasburicase-treated subjects suggests potential different effects of uricase treatment on hemodynamic alterations in renal function versus structural mechanisms of kidney injury.