Trasylol's German maker, Bayer AG, suspended marketing in the United States last November after preliminary results from this trial revealed problems with the medication. On Wednesday, following release of the new findings, the U.S. Food and Drug Administration said the manufacturer had begun removing any remaining stock of the drug from the U.S. market.

"In the trial, we asked whether aprotinin [Trasylol] was more effective at reducing massive bleeding during high-risk heart surgery compared to other drugs," lead investigator Dr. Dean A. Fergusson, from the University of Ottawa Centre for Transfusion Research, said during a teleconference Monday.

"We also asked were serious complications, such as death and organ failure, lower for aprotinin compared to the two other drugs," Fergusson said.

The report was released online Wednesday by theNew England Journal of Medicineand will appear in its May 29 issue.

In the Canadian trial, known as BART, Trasylol was compared with two similar drugs Cyklokapron (tranexamic acid) and Amicar (aminocaproic acid).

During the trial, 2,331 high-risk cardiac patients undergoing heart surgery were randomly assigned to one of the three drugs.

"The most important outcome of the trial was a bit of surprise," co-principal investigator Dr. Paul C. Hebert, a critical care physician at Ottawa Hospital, said during Monday's teleconference.

The rate of death from Trasylol was 6 percent versus 3.9 percent and 4 percent for the other two drugs, Hebert said. "This represents a 53 percent of relative risk of dying, which translates into for every 50 patients treated with aprotinin, one patient would die," he said.

Most of the deaths associated with Trasylol were from cardiac complications, Hebert said. Because of the significant increased risk of death, the trial was stopped in October 2007, before the scheduled completion date.

The researchers concluded that while Trasylol may have a small advantage in reducing massive bleeding, the increased risk of death precluded the use of the drug in patients undergoing high-risk heart surgery. "That's the statement at the end of the paper, and we stick by it," Hebert said.

However, despite the drug being pulled off the market in many countries, Bayer continues to sell Trasylol in some areas of the world.