Each year 1 in 1000 people will experience venous thrombosis, a condition characterized by the occurrence of blood clots in deep veins. Its treatment consists of blood thinners for 3 to 6 months. After discontinuation of blood thinners, there is a risk of recurrent venous thrombosis. In some cases blood thinners are continued indefinitely to prevent these recurrences. However, blood thinners have a risk of bleeding. Therefore, indefinite treatment is only done in cases of a high recurrence risk and low bleeding risk.
The risk of recurrence is high in the case of unprovoked venous thrombosis. In almost half of patients a provoking factor is absent. This implies that a large group of patients is exposed to bleeding risks of blood thinners in the long term. In this thesis of Bibie Bhoelan is investigated whether we could identify patients in whom indefinite treatment is not necessary within the group with an unprovoked venous thrombosis.
We showed that existing risk scores are yet not useful for clinical practice. Subsequently, we investigated whether presence inflammation and infection in otherwise unprovoked venous thrombosis is associated with a lower recurrence risk, similar to other known provoking factors. Transient inflammation and infection seem to be associated with a lower recurrence risk. However, this risk was not low enough to refrain from indefinite treatment. Transient inflammation and infection could possibly be added to existing risk scores and thereby identify patients with a low enough recurrence risk.
