Anticoagulating people forever after unprovoked VTE lacks robust evidence
Do you really benefit from DOAC in year 5, 6 or 17
Just out, and led by UCSF medical student Anushka Walia, we investigate anti-coagulation for unprovoked VTE, which is typically discussed as “lifelong”— does it make sense?
The real question is: do patients benefit from continued anti-coagulation at year 4, 6, or 17?
In the essay, we articulate a series of concerns
Provoked vs unprovoked is an inexact science. Any hematologist will tell you there is lots of gray here, and yet the distinction has massive impact on long term risk of DOAC
Each year, we find more clots than before— and much smaller clots. How many people anti coagulated for sub-segmental clots? Data on VTE risk always lags the clot sizes now found.
It is important to consider the shape of the hazard function for clot and bleeding risk. They are not the same, and the curves may cross. Clot risk eventually plateaus, but bleed risk is more volatile, depending on subsequent medical issues.
We know nearly nothing about long term mortality or HRQoL
Ultimately, I have little confidence in clinic that continuing anticoagulation in year 7 or 10 after an ‘unprovoked clot’— as someone ages— is a good idea. Yet, this is too often the inertia of standard practice. Our essay forces us to revisit this question.
Check out the full essay attached here.
