Article Review 

Despite advances in cardiopulmonary bypass (CPB) during cardiac surgery, acute kidney injury (AKI), has a still a 30–50% incidence. Statins are commonly used as lipid-lowering drugs, and their anti-inflammatory and antioxidant effects are thought to prevent vascular events by stabilising atherosclerotic plaques. They can also improve endothelial function, release vasodilator substances such as nitric oxide, and reduce levels of the endothelin-1, a potent vasoconstrictor. Accounting for these pleiotropic properties, clinicians hypothesised that statins could preserve major organ function in various patient subsets. They have gained attention as a way to reduce AKI after cardiovascular surgery through their anti-inflammatory and antioxidant activities. Indeed, results of randomised controlled studies showed that not only continuing or postprocedural statin treatment but also short-term pretreatment with statins significantly reduced contrast-induced AKI and major adverse cardiac events.

The authors of this recent study published in Intensive Care Medicine (Sept 2016) investigated the potential preventive role of perioperative atorvastatin on AKI, in a double-blind, randomised, placebo controlled trial involving 200 statin-naïve patients undergoing valvular heart surgery. The intervention group was scheduled to receive 80 mg single dose on the evening prior to surgery; 40 mg on the morning of surgery; and three further doses of 40 mg on the evenings of postoperative days (POD) 0, 1, and 2. From both groups, 100 patients were randomly selected at a 1:1 ratio for the measurement of plasma neutrophil gelatinase-associated lipocalin (NGAL) and interleukin (IL)-18 levels. The primary end point was the incidence of postoperative AKI as defined by the Acute Kidney Injury Network (AKIN) criteria for more than 6 h within 48 h after surgery. The secondary end points were changes in serum biomarkers including sCr, plasma NGAL, and IL-18 during the perioperative period. sCr was recorded 24 h before surgery; on arrival to the intensive care unit (ICU); and on POD 1, 2, 3, and 5. The incidence of AKI was similar in the statin and control groups (21 vs. 26%, respectively, p = 0.404). Biomarkers of renal injury including plasma NGAL and IL18 were also similar between the groups. The statin group required significantly less norepinephrine and vasopressin during surgery, and fewer patients in the statin group required vasopressin. There were no significant differences in postoperative outcomes. 

Conclusions  
Although some limitations of the study (especially AKI incidence lower than expected), these results do not confirm that acute perioperative statin treatment was associated with a lower incidence of AKI or attenuation of biomarkers related with renal injury in patients undergoing valvular heart surgery. 

Article review was prepared by Gennaro De Pascale and Temistocle Taccheri on behalf of the ESICM NEXT Committee.

Reference 

Park et al. Effect of atorvastatin on the incidence of acute kidney injury following valvular heart surgery: a randomised, placebo-controlled trial. Intensive Care Med, Original, Volume 42, Issue 9 / September, 2016, Pages 1398 – 1407