A clinical trial involving an experimental blood substitute that was linked to heart attacks in patients with cardiac problems will continue in Richmond despite an outcry from some in the medical community.
Virginia Commonwealth University Medical Center is one of 31 hospitals across the country involved in the trials. VCU officials said last week that doctors and federal regulators had looked into an earlier study linking the fake blood to heart attacks and other problems, and deemed it safe enough to continue the current trials.
On Feb. 22, The Wall Street Journal reported that Northfield Laboratories had failed to publicly disclose an earlier study involving their blood substitute, known as PolyHeme, wherein all of the 10 patients who received infusions suffered heart attacks. Two of them died.
Northfield didn’t submit a full report of its findings to potential participants in the current trials, which began in 2004. Some doctors told The Journal that they demanded Northfield report the findings publicly, but the company did not.
The differences between the earlier study which led to heart attacks and the current one are like comparing “apples and oranges,” say officials at VCU. In the earlier study, the patients who received the fake blood were older and were infused during cardiac surgery. In the current study, PolyHeme is administered to trauma patients, such as accident and gunshot victims, who have lost large amounts of blood.
Because trauma patients are often unable to give their consent, the FDA allows Northfield to administer PolyHeme on unwitting patients after holding a series of community meetings in areas where the trial is taking place.
Dr. Rao Ivatury, director of trauma and surgical critical care at VCU Medical Center, says he’s reviewed the controversial study and found Northfield’s explanation that the heart attacks were caused by doctors misapplying PolyHeme — essentially giving patients too much — is plausible.
“There is no evidence that the results [the heart attacks] are from PolyHeme,” Ivatury says, adding that the current, larger study has found no similar problems. The study involves 600 patients, of which VCU is responsible for 40. Also, the FDA and the Internal Review Board, a federal agency that sanctions human clinical trials, has looked into the earlier study and decided the current PolyHeme trial can continue.
Some aren’t satisfied. Dr. Bruce Spiess, a anesthesiologist at VCU Medical Center who is heading a study of another synthetic blood substitute, says the problems with PolyHeme appears to be similar to those of other hemoglobin-based blood substitutes that have failed in the past. They tend to constrict blood vessels, which can lead to heart attacks.
“The possibility of heart attacks looks to me to be real,” says Spiess. “I would put everything on hold until you are sure the patients aren’t at risk.” S
