Statins are effective drugs for lowering LDL cholesterol and have been associated with a reduction in cardiovascular morbidity and mortality. Do they have any other benefits? Dr. Maged Y. Argalious, Department of General Anesthesia, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH and coauthors hypothesized that preoperative statin use may provide renal protection in patients undergoing non-cardiac surgery. The results of their study, “The Association of Preoperative Statin Use and Acute Kidney Injury After Noncardiac Surgery,” appear in the current issue of Anesthesia & Analgesia.
The authors used their electronic medical record to find patients who used statin drugs preoperatively. These patients were propensity matched to similar patients who did not use statins preoperatively. Their analysis included ASA physical status 1-4 patients who underwent surgery between December 8, 2004, and March 8, 2010. They excluded patients with any history of kidney disease. Over 28,000 patients were identified. The authors propensity matched 4172 patients on statins with control patients.
Acute kidney injury occurred in 7.1% in matched statin users and 8% in nonusers, a difference that was not statistically significant. Need for dialysis was indistinguishable: 0.1% and 0.12% respectively. Mortality rates were also indistinguishable: 1% and 1.3% respectively.
As the authors note, no drug has been shown to prevent ischemic renal injury. In a study published last month, some of these same authors showed that when mean arterial pressure is less than 55, the incidence of acute kidney injury and myocardial injury increases. Both studies are retrospective and as such are associated with possible bias.