“We found that bleeding risk was higher in older, sicker patients or those with a history of bleeding. This new information will be very helpful for patients and clinicians who need to weigh the benefits and risks of long-term treatment”- Faizan KhanOver 750,000 Canadians will have an unexplained vein blood clot in their lifetime, known as venous thrombosis. Guidelines suggest that these people take blood thinners for life to prevent a second clot. Unfortunately, blood thinners come with a risk of bleeding that can be fatal, and the risk beyond three to six months of use is uncertain.
A new systematic review and meta-analysis led by Faizan Khan and published in Annals of Internal Medicine now provides the best data yet on the long-term risks and consequences of bleeding with different blood thinners. The team combined data from 27 relevant studies involving 17,202 patients.
They found that for every 1,000 people who use vitamin K antagonists for a year, 17 will have a major bleeding event, and for every 1,000 people who use a direct oral anticoagulant for a year, 11 will have a major bleeding event. One in every 10 to 12 bleeding events resulted in death. The researchers also estimated risks over 10 years and looked at the impact of other conditions.
“We found that bleeding risk was higher in older, sicker patients or those with a history of bleeding. This new information will be very helpful for patients and clinicians who need to weigh the benefits and risks of long-term treatment,” said lead author Faizan Khan, a PhD candidate at the University of Ottawa and The Ottawa Hospital.
Authors: Faizan Khan, Tobias Tritschler, Miriam Kimpton, Philip S. Wells, Clive Kearon, Jeffrey I. Weitz, Harry R. Büller, Gary E. Raskob, Walter Ageno, Francis Couturaud, Paolo Prandoni, Gualtiero Palareti, Cristina Legnani, Paul A. Kyrle, Sabine Eichinger, Lisbeth Eischer, Cecilia Becattini, Giancarlo Agnelli, Maria Cristina Vedovati, Geert-Jan Geersing, Toshihiko Takada, Benilde Cosmi, Drahomir Aujesky, Letizia Marconi, Antonio Palla, Sergio Siragusa, Charlotte A. Bradbury, Sameer Parpia, Ranjeeta Mallick, Anthonie W.A. Lensing, Martin Gebel, Michael A. Grosso, Kednapa Thavorn, Brian Hutton, Gregoire Le Gal, Dean A. Fergusson, Marc A. Rodger, MAJESTIC Collaborators
Funding: Canadian Institutes of Health Research. All research at The Ottawa Hospital is also enabled by The Ottawa Hospital Foundation.
Source: Annals of Internal Medicine, free patient summary
Core resources: Ottawa Methods Centre
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