Statin initiation and renal outcomes following isolated coronary artery bypass grafting: a meta-analysis.

INTRODUCTION: The effects of preoperative statin therapy (PST) on renal outcomes in patients with isolated coronary artery bypass grafting (CABG) are in controversial. This study aimed to assess the effects of preoperative statin use on postoperative renal outcomes in patients undergoing isolated CABG. EVIDENCE ACQUISITION: PubMed, EMBASE, and Cochrane Library were searched for studies published up to February 2017. Pooled odds ratio (OR) and its corresponding 95% confidence interval (95% CI) were calculated. Outcomes evaluated were occurrence of postoperative acute kidney injury (AKI)/failure, requirement of any postoperative renal replacement therapy (RRT) and change in serum creatinine (Scr) levels. We used random-effects model and calculated pooled effect estimate of outcome between statin and non-statin use groups. EVIDENCE SYNTHESIS: Eighteen studies consisting of 32,747 patients following CABG were included. PST was associated with a significant protective effect for perioperative renal dysfunction (OR 0.89; 95% CI: 0.82-0.97; P=0.01) and postoperative requirement for RRT (OR 0.54; 95% CI: 0.41-0.72; P=0.001) in patients undergoing CABG surgery. However, there were no effects of preoperative statin therapy on the risk of postoperative AKI and serum creatinine concentration. In the subgroup of patients after on-pump CABG surgery, PST significantly reduced the perioperative renal dysfunction and requirement for RRT (OR 0.69; 95% CI: 0.53-0.89; P=0.005, OR 0.51; 95% CI: 0.30-0.87; P=0.014, respectively). CONCLUSIONS: In patients undergoing isolated CABG, PST might be associated with lower risk of postoperative renal dysfunction and the requirement for RRT. However, PST may not reduce the risk of AKI. Future large well-designed randomized controlled trials are needed on this topic.