However, significantly more patients in the treatment group had an MI – mostly early – after surgery (500 vs. 408 in the placebo group), an increased risk of 22%, which was statistically significant.
The use of methylprednisolone was not associated with an altered risk of other stroke, new renal failure, or respiratory failure, or other outcomes measured, including transfusion requirements, new-onset atrial fibrillation, length of ICU or hospital stay, surgical site infections, delirium, or GI complications, Dr. Whitlock said.
When asked about a possible mechanism behind the SIRS results, Dr. Whitlock said that one possible explanation could be that since one of the important early recovery strategies after myocardial injury is movement of glucose into cells, and insulin requirements increase in the steroid-treated patients, "it is possible that we’re inducing insulin resistance: Thereby, glucose is not entering the myocyte for the recovery phase after the ischemic insult." While that is plausible, he added, "we really don’t have the answer. What is important is the signal is clear, it’s clear across all subgroups, and it is a prognostically important increase."
Dr. Amit Khera, director of the preventive cardiology program at UT Southwestern Medical Center, Dallas, commented that SIRS was a definitive study, and this use of methylprednisolone, at least at higher doses, "should not be a strategy we should pursue."
The SIRS trial was conducted by the Population Health Research Institute at the Hamilton Health Sciences and McMaster University during 2007-2014 and was funded with grants from the Canadian Institutes for Health Research and the Canadian Network and Centre for Trials Internationally. Dr. Whitlock said he had no relevant financial disclosures.