Background: Older subjects, including those with normal renal function, have an increased risk of acute kidney injury. Preoperative statin therapy has been reported to improve renal outcome after cardiac surgery and to reduce inflammatory response to cardiopulmonary bypass. No study has hitherto evaluated whether the positive effect of pretreatment with statins on postoperative renal outcome is due to their positive effect on inflammatory burst in elderly patients undergoing myocardial revascularization using cardiopulmonary bypass.
Methods: Sixty-nine consecutive elderly patients to undergo isolated coronary artery bypass were enrolled and divided in two groups according to preoperative statin therapy (statin group n = 39) or not (no-statin group n = 30). Primary end-points of this study were the incidence of postoperative acute kidney injury defined by Acute Kidney Injury Network (AKIN) criteria, of acute renal failure needing renal replacement therapy, and the rate of complete recovery of kidney function. Secondary outcomes were perioperative changes of inflammatory and anti-inflammatory cytokines (IL-1β, IL-2, IL-6, IL-8, IL-10 and TNF-α serum level).
Results: Incidence of acute kidney injury was similar between the two groups within 2 days after surgery (statin group 18/30 vs. no-statin group 18/39 P = 0.25). However, statin patients showed significantly higher glomerular filtration rate at 10th postoperative day than no-statin patients (statin group 80 ± 31.1 ml/min vs. no-statin group 59.2 ± 29.5 ml/min, P = 0.006). No significant difference in cytokine levels was observed, except for a higher IL-10 release in no-statin group at 24 h after surgery (statin group 130.22 ± 174.37 pg/ml vs. no-statin group 273.422 ± 351.52 pg/ml, P = 0.03).
Conclusions: In elderly patients, preoperative statin treatment allows better recovery of renal function following cardiopulmonary bypass but not by an anti-inflammatory effect.