Would you extend the duration of anticoagulation in patients with a provoked DVT, but evidence of residual clot at 3 months?

This is a really interesting discussion. I do tend to get Dopplers at the end of the anticoagulation treatment period, but only to assess the new baseline and to help decision-making in the future if they develop new symptoms and have another Doppler. I find this to be very helpful to understand if a future "clot" is chronic or new. However, I do not use this to inform the initial anticoagulation duration.

While there are many studies that show that residual venous obstruction (RVO) after treatment leads to an increased risk of future thrombosis, there are also studies that show the risk is not increased. For the subset of provoked clots, in particular, most studies showing increased risk included cancer as a provoking factor. A systematic ...

Residual changes on the follow-up duplex scan may be associated with an increased risk of recurrence. This is particularly true if the patient has other co-morbidities that can be graded with the Caprini score. If the residual changes are minimal, I would advise a D-dimer and Factor VIII assay on anticoagulation and if elevated, would not stop anticoagulation. I have seen many patients with provoked VTE that recur when AC is stopped after 3 months. Look for a further discussion of my thoughts that will appear on my YouTube channel soon (Caprini venous resource center). You can always email me for references and other information regarding this question. jcaprini2@aol.com.

If the patient is younger, has no ongoing risk factors for thrombosis, and has tolerated the therapy well, I would continue treatment for another 3 months. If risk factors are present, I would continue indefinitely.