Elevated doses of atorvastatin, a member of a drug class known as statins, does not reduce the risk of acute kidney injury after cardiac surgery, according to a recent study titled “High-Dose Perioperative Atorvastatin and Acute Kidney Injury Following Cardiac Surgery, A Randomized Clinical Trial,” preformed by Vanderbilt University Medical Center (VUMC) researchers in collaboration with the Harvard University School of Medicine, and published in the JAMA journal.
According to a previous study published in CJASN , up to 30 percent of patients develop acute kidney injury (AKI) after cardiac surgery, and 1 percent of them will require dialysis to keep them alive.
Following cardiac surgery, patients are commonly treated with a long-term statin therapy as it has favorable outcomes in terms of serum creatinine, a species indicative of renal health.
Some studies have speculated that high doses of atorvastatin would decrease AKI after cardiac surgery. To test this hypothesis, researchers investigated 615 patients with an average age of 67 who underwent cardiac surgery between November 2009 and October 2014 at VUMC.
199 patients who never took statins (called statin-naive) were administrated 80 mg. of atorvastatin the day before surgery, 40 mg. the morning of surgery, and 40 mg daily after surgery.
416 patients who used statins before their trial enrollment continued on prescribed statins until the day of surgery, then were put on 80 mg. of atorvastatin the morning of surgery and 40 mg. after surgery, resuming the previous dosage after day 2 of surgery.
The results revealed an increase in serum creatinine levels by 0.3 mg/dL (milligrams per deciliter) within 48 hours after surgery, indicative of AKI. As a result, the data and safety monitoring board decided to stop medicating the group who had never received statins before surgery (the naive group), later advising researchers to stop the trial for futility once the 615 patients completed the study.
AKI occurred in 64 out of 308 (20.8 percent) in the atorvastatin group compared with 60 of 307 (19.5 percent) in the placebo group. In the statin-naive group, 22 of 102 (21.6 percent) had AKI in the atorvastatin group compared with 13 of 97 (13.4 percent) in the placebo group. Also, increase in serum creatinine levels was higher in the atorvastatin group (median 0.11 mg/dL) when compared to the placebo group (median 0.05 mg/dL).
Among patients who previously took a stati, AKI occurred in 42 of 206 (20.4 percent) in the atorvastatin group compared with 47 of 210 (22.4 percent) in the placebo group.
The authors concluded that the results did “not support the initiation of statin therapy to prevent AKI following cardiac surgery.”
According to a news release, in a related paper also published in JAMA, Rinaldo Bellomo, MBBS(Hons), M.D., FRACP, FCICM, wrote, “These findings provide important additional evidence that continuing perioperative statin therapy is likely safe, rational, easy, inexpensive, and perhaps slightly protective against [acute kidney injury] for patients undergoing cardiac surgery. In contrast, the results suggest that initiating perioperative statin therapy in patients naive to statin treatment undergoing cardiac surgery may be injurious to the kidney.”
“In the absence of any other convincing evidence of benefit, these findings strongly argue in favor of not administering statins to patients naive to statin treatment about to undergo cardiac surgery,” said Bellomo, from the intensive care unit at Austin Hospital and the school of medicine at the University of Melbourne, Australia.