Statins are the most prescribed drugs in the world. They are usually taken to lower cholesterol, though they also lower the risk of heart attack, premature death, and stroke. The evidence is mixed concerning the risk of developing acute respiratory distress syndrome (ARDS) in patients taking statins.
Dr. Daryl J. Kor, Department of Anesthesiology and Division of Critical Care Medicine, Mayo Clinic, Rochester, Minnesota, and coauthors evaluated the association between preoperative statin therapy and the development of ARDS in a group of patients at increased risk of developing postoperative ARDS: patients undergoing high-risk vascular and thoracic surgery. The results of their analysis are discussed in the article titled “Preoperative Statin Administration Does Not Protect Against Early Postoperative Acute Respiratory Distress Syndrome: A Retrospective Cohort Study,” published in this month’s issue of Anesthesia & Analgesia.
The authors used the detailed and perhaps unique databases, search strategies, and tools available at the Mayo Clinic in Rochester, Minnesota. They studied patients who underwent this high-risk surgery between January 1, 2005, and November 11, 2010. A total of 1845 high-risk surgery patients were identified and included in the study. Within this group, 722 patients had been taking statins preoperatively and 1123 had not. The incidence of postoperative ARDS did not differ between those patients receiving statin therapy compared to those who were not (7.2% and 6.1%, respectively). Propensity score matching confirmed these findings. More specifically, in the two groups of patients who developed postoperative ARDS, there were no statistically significant differences in mortality (7.7% vs. 8.8%), ventilator-free days (24 days vs. 25 days), ICU length of stay (8.3 days vs. 7.1 days), or hospital length of stay (21 days vs. 15 in the patients who were receiving preoperative statins as opposed to those who were not).
As the authors noted, this was a retrospective observational study. The authors did not analyze the duration of statin therapy prior to surgery. If statin therapy might be beneficial, how long might statin therapy be needed before the risk of ARDS is present? Although the authors discounted the possible negative impact of stopping the statins during the perioperative period (i.e., the risk of rebound negative effects), it seems notable that statins were not restarted for more than 5 days, if at all, in 33% of the patients who were taking statins preoperatively.
Although this study does not support the routine use of statins to reduce the risk of developing postoperative ARDS, it does not rule out the possibility that preoperative statins could be beneficial if administered for some yet-to-be-determined period of time preoperatively. Thus, there is still a need for large prospective studies to answer these questions.