Dr. Keyvan Karkouti siting on a bench
Dr. Keyvan Karkouti, Chief of Anesthesia at Toronto General Hospital, is co-Principal Investigator of the study, which was published Monday in The Journal of the American Medical Association (JAMA). (Photo: UHN)

We can't predict when there will be another "tainted blood" outbreak, but we do know that we are now safer than ever before because of a landmark new study conducted at Toronto General Hospital.

It's been almost 40 years since thousands of people were infected with HIV from contaminated blood products, and thousands more with hepatitis C. Tragedy forced lessons on us, and now the Canadian blood supply is one of the safest in the world.

But safety requires vigilance, innovation and modernization.

For decades, North American hospitals have been using cryoprecipitate to replace fibrinogen, an important clotting factor, in patients who bleed during or after surgery. Cryoprecipitate is a blood product derived from plasma that is both costly and cumbersome to produce, and slow and inefficient in an operating room when time is of the essence.

In Europe, where "mad cow" disease more recently killed Britons and struck fear in their hearts for decades, cryoprecipitate was long ago replaced with fibrinogen concentrate, a more pure blood product.

"We had a purified and likely safer product," says Dr. Keyvan Karkouti, Chief of Anesthesia at Toronto General Hospital (TG). "But, because we didn't have comparative data, here in North American we didn't make the switch."

As in most cases of invention, it was necessity that moved Dr. Karkouti and Dr. Jeannie Callum, Director of Transfusion Medicine and Tissue Banks, Sunnybrook Health Sciences Centre, co-Principal Investigators, and a team of scientists, to prove one blood product is better and safer than the other.

The results of the multicentre, randomized clinical trial conducted at 11 hospitals across Canada was published in The Journal of the American Medical Association (JAMA).

Dr. Michael Farkouh
Dr. Michael Farkouh is lead cardiologist on the trial and Peter Munk Chair in Multinational Clinical Trials at Toronto General Hospital. (Photo: UHN)

The study proves that fibrinogen concentrate is just as effective as cryoprecipitate with more benefits to both the bottom line and to patient welfare. Cryoprecipitate comes from blood collected by donors, which is then processed, frozen and shipped to urban centres. It is an expensive and time-consuming production process for our blood suppliers that also negatively impacts their ability to produce other urgently needed blood components such as platelets.   

In terms of safety, the fibrinogen concentrate is solvent-detergent treated and multi-filtered to inactivate any potential pathogens. And because it does not require freezing, it can be used almost instantly.

With cryoprecipitate, it takes up to 45 minutes to thaw and combine the 10 units that may or may not have the right balance of fibrinogen needed to stop the bleeding. It is very common in trauma, obstetrical and cardiac surgery cases to have a patient who requires blood to survive, and in those cases, every minute counts.

"We are the doctors that send our patients into surgery," says Dr. Michael Farkouh, lead cardiologist on the trial and Peter Munk Chair in Multinational Clinical Trials at TG. "We want them to have optimal outcomes and this clinical trial will lead to safe and effective management of bleeding in surgery."

Currently in Canada, fibrinogen concentrate is approved for use only for patients who have low fibrinogen levels from birth, which is a very rare condition. Its use in the much more common situation of surgical bleeding because of low fibrinogen levels is considered off label. Because of this landmark study, such patients will also be able to receive the best available treatment.  

"As a result of this study, Canadian hospitals can now wholeheartedly switch over to fibrinogen concentrate," says Dr. Callum. "We trust our blood supply, but we don't know what infection risks are around the corner and this product is safer than cryoprecipitate in that regard." 

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