Statin users are less likely to develop postoperative acute kidney injury (AKI) than are nonusers, according to new data from an observational study. The investigators suggest that preoperative statin therapy might, therefore, be an effective strategy for the prevention of postoperative AKI.

Interestingly, the observed benefit of statin therapy differed according to the type of surgery...

To evaluate whether preoperative statin use is associated with a decreased risk of postoperative AKI, Brunelli and colleagues studied a retrospective cohort of 98,939 patients who underwent elective cardiac, thoracic or abdominal surgery between 2000 and 2010. Of these patients, 7,971 statin users were pair-matched with nonusers on the basis of factors that might affect risk of AKI, including type of surgery, baseline estimated glomerular filtration rate, and length of time between hospital admission and surgery. The researchers used conditional logistic regression models to compare the frequencies of postoperative AKI (defined using the AKIN and RIFLE staging systems and need for renal replacement therapy) in the matched groups.

The researchers found that preoperative statin use resulted in an 18–22% relative reduction in the risk of postoperative AKI, depending on the AKI definition used. The association between statin therapy and reduced risk of postoperative AKI was not affected by the presence of diabetes mellitus or chronic kidney disease in patients undergoing surgery.

“Interestingly, the observed benefit of statin therapy differed according to the type of surgery” says Brunelli. “Patients undergoing vascular surgery seemed most likely to benefit from statins, those undergoing cardiac surgery were the least likely to benefit, and those undergoing thoracic and abdominal surgery fell inbetween.” The researchers speculate that haemodynamic insults could “override” the protective effects of statins in patients undergoing cardiac surgery.

Although these data suggest that starting patients on statin therapy during the preoperative period might protect against postoperative AKI, Brunelli is cautious; “ultimately a randomized clinical trial is needed to definitively test whether statins are of benefit in preventing postoperative AKI”, he explains. “In addition, any benefits of statins with respect to AKI prevention would need to be weighed against potential adverse effects.”