Giving steroids to reduce inflammation during cardiopulmonary bypass has no benefit, and may in fact harm patients who receive the drugs, new research shows.
An international study of more than 7,500 patients, the largest of its kind to date, is the latest to find that the prophylactic administration of IV steroids during bypass procedures does not reduce mortality or prevent heart attacks in this population. Roughly one-fourth of hospitals worldwide use the treatment—suggesting that thousands of patients each year may be at risk from the approach.
Taken with the findings of a 2012 Dutch study, DECS (Dexamethasone for Cardiac Surgery), the new results may mean that the use of steroids to reduce postoperative myocardial infarction (MI) has reached a dead end.
“I want to be careful to avoid throwing the baby out with the bath water here. The crux of the hypothesis was that inflammation is bad, and cardiopulmonary bypass incites a lot of inflammation in these patients,” said Richard Whitlock, MD, assistant pro fessor of cardiac surgery at McMaster University in Hamilton, Ontario, Canada, who led the trial. “Now, with SIRS [Steroids in CaRdiac Surgery trial] and DECS we have more than 12,000 patients for whom a therapy that strongly suppresses that inflammatory response shows no clinical benefit. It does suggest that this is a pathway into which further resources should not be invested.”
What’s more, not only do steroids not appear to help, the studies show an “important signal of harm”—more heart attacks, Dr. Whitlock said. “This is a novel finding, and it will perhaps open up pathways” to investigate. “This pathway of MI caused by steroids—if it’s glucose-based, maybe some therapy that focuses on glucose control” will help where previous approaches have failed.
The DECS researchers reported no benefit from dexamethasone in patients having coronary artery bypass grafting, although the drug did appear to reduce the risk for death, heart attack and other poor outcomes in the sickest patients. That ambiguity left room for the results of the recent SIRS trial—which experts hoped would definitively answer the question.
The 7,507 patients in SIRS, who were considered to be at high risk for poor outcomes, received either 500 mg of IV methylprednisolone intraoperatively or a placebo injection. The researchers performed intention-to-treat analyses on 3,755 patients in the steroid arm and 3,752 patients in the placebo arm.
The two primary end points were total mortality within 30 days of surgery and a composite of death, MI, stroke, new-onset kidney failure and respiratory failure. Secondary outcomes included transfusion requirement within 24 hours of surgery, hospital and ICU lengths of stay, delirium, and two measures of blood sugar: postoperative use of insulin and peak blood glucose concentrations.
More patients in the steroid group experienced an MI after surgery than in the placebo arm (13.3% vs. 10.9%, respectively; P=0.001), according to the researchers. Those events tended to occur within the first 72 hours after the procedure, and most were non–Q-wave MIs.
C. David Mazer, MD, a professor in the Department of Anesthesia at the University of Toronto, said many centers use steroids for patients undergoing deep hypothermic arrest. The latest data “raise the issue of whether we should be using” steroids in this population, Dr. Mazer said.