“We see two to three people with unexplained blood clots every day at The Ottawa Hospital. Tools like these can help us counsel patients and guide the duration of their treatment.” -Dr. Phillip WellsOver 750,000 Canadians will have an unexplained vein blood clot in their lifetime, known as venous thrombosis.
These people may need to take blood thinners for the rest of their lives, but that decision requires balancing the risk of bleeding with the long-term risk of a second clot if treatment is stopped. Unfortunately, there is a lot of uncertainty around these risks.
A collaborative international study led by Dr. Philip Wells created a new tool to predict bleeding risk in these patients and compared it to existing risk scores, which they customized for this patient population.
In this study published in Blood Advances, the researchers followed 2,516 venous thrombosis patients from 12 centres who were taking life-long blood thinners, and recorded their risk characteristics and bleeding events.
Based on this data, they found that modified versions of the ACCP, VTE-BLEED, and HAS-BLED scores accurately predicted major bleeding in this population. The new CHAP tool they created during this study also had similar predictive power, but requires external validation before it can be used in the clinic.
“We see two to three people with unexplained blood clots every day at The Ottawa Hospital. Tools like these can help us counsel patients and guide the duration of their treatment.” -Dr. Phillip Wells, senior scientist at The Ottawa Hospital and professor at the University of Ottawa
Authors: Philip S. Wells, Tobias Tritschler, Faizan Khan, David R. Anderson, Susan R. Kahn, Alejandro Lazo-Langner, Marc Carrier, Grégoire Le Gal, Lana A. Castellucci, Vinay Shah, Scott Kaatz, Clive Kearon, Susan Solymoss, Russell Zide, Sam Schulman, Isabelle Chagnon, Ranjeeta Mallick, Marc A. Rodger, Michael J. Kovacs
Funders: This study was funded by the Canadian Institutes of Health Research and the Heart and Stroke Foundation. Research at The Ottawa Hospital is possible thanks to generous donations to The Ottawa Hospital Foundation.
The Ottawa Hospital is a leading academic health, research and learning hospital proudly affiliated with the University of Ottawa and supported by The Ottawa Hospital Foundation.
