Aprotinin, a drug used to limit bleeding, was temporarily suspended from marketing in the U.S. in November 2007 after a small Canadian study was stopped because similar findings were discovered. "We're not surprised by the results,” says Dr. Andrew Shaw, an associate professor in Duke Medicine’s department of anesthesiology and the lead author of the paper.
The prospective data was collected between 1996 and 2005, a time when aprotinin was thought to be safe. “Unlike the highly selected nature of randomized trial populations, our data represent the every day cardiac bypass surgery patient population. The Duke team started analyzing its database of patients after a 2006 NEJM study reported aprotinin use may increase the risk of heart attack, stroke and serious kidney injury. The study found aprotinin use increased serum creatinine levels, but they did not report an increase in patients needing dialysis. Shaw believes “that’s because we probably didn’t have enough patients who needed dialysis in our study to detect a significant statistical difference, although the incidence was numerically higher.”
Of the 10,275 patients studied, 1343 patients (13.2%) received aprotinin, 6776 patients (66.8%) received aminocaproic acid and 2029 patients (20.0%) received no therapy. All patients underwent coronary-artery bypass surgery, and 1181 of them also underwent valve surgery. Patients who received either aminocaproic acid or no therapy did not have high rates of death or poor kidney function seen in the aprotinin group.
Shaw says this study does not rule out the possibility that the increased death rate was due to high-risk, sicker patients receiving the drug. “The unanswered question is, ‘are there differences between the patient groups that we were unable to detect that led to the increased death rate, or is the death rate due to exposure to the drug?’”, he said. “Our study doesn’t answer that question nor was it designed to,” he added. “But it does further raise the question of the safety of aprotinin.
MEDICA.de; Source: Duke University Medical Center