HMG COA reductase inhibitors (statins) for preventing acute kidney injury after surgical procedures requiring cardiac bypass: A systematic review and meta-analysis

Aim: To assess evidence supporting benefits of perioperative statins to prevent acute kidney injury (AKI) after cardiac bypass surgery. Further, to determine if use is associated with reduction in mortality, need for renal replacement therapy (RRT) or if adverse effects are associated with use. Background: AKI is common in patients undergoing cardiac surgery and is associated with poor outcomes, prolonged hospital stays and increased mortality. Statin drugs exert multiple pleiotropic effects independent of lipid lowering effect, and may ameliorate AKI through inhibition of postoperative inflammatory responses. Methods: Systematic review and meta-analysis. Randomised controlled trials (RCT's) comparing statin therapy to standard care in adult patients undergoing cardiac bypass surgery and reporting one of AKI, mortality, serum creatinine or need for RRT. All forms/dosages of statin and any duration of preoperative therapy were considered for inclusion. Results: Seven trials (662 participants). Six of the seven trials were rated as high risk of bias. Three trials assessed atorvastatin, three simvastatin and one rosuvastatin. Overall, statin treatment was not associated with a reduction in postoperative AKI, need for RRT or mortality. Two studies (195 patients) reported postoperative serum creatinine. Patients receiving statins had lower postoperative serum creatinine compared placebo (mean difference 21.2 (mu)mol/L, 95%CI -31.1, -11.1). Adverse effects were only adequately reported in one trial, with no difference seen between groups. Conclusions: The analysis does not suggest that preoperative statin use is associated with decreased AKI in adults after cardiac bypass surgery. Other results must be interpreted with caution as only a limited number of studies were included in subgroup analyses. High quality RCT's are still required to establish the utility of statins to prevent AKI after cardiac surgery.