Negative d‐dimers justify stopping anticoagulants in women but not in men after a first unprovoked venous thromboembolism, a Canadian study shows.
Long‐term VTE recurrence risk was high for men with negative d‐dimer levels in the five years after a first unprovoked proximal DVT or pulmonary embolism (PE), but not for women, according to results published in the Journal of Thrombosis and Haemostasis.
In the study, 410 patients with a first unprovoked VTE had anticoagulants stopped if d‐dimer was negative on therapy and one month after stopping therapy.
The subsequent rate of recurrent VTE was 5.1% per patient‐year overall, 7.5% in men, 3.8% in women (with VTE not associated with oral contraception or hormone replacement therapy) and 0.4% in women with VTE associated with oestrogens.
Cumulative risk of recurrence at five years was 21.5% overall, 29.7% in men, 17.0% in women not taking oestrogen and 2.3% in oestrogen-using women.
The study investigators said their findings should help inform decisions about whether a patient with unprovoked VTE should receive indefinite anticoagulation or not.
“The clinical implications of these findings are that the risk of recurrence in men is too high to justify routinely stopping anticoagulant therapy in response to negative d‐dimer testing,” they wrote.
“The risk of recurrence in women with unprovoked VTE (and not related to oestrogens) who have negative d‐dimer testing is low enough that that many may choose to stop anticoagulants, provided there are no other reasons to continue therapy.”
But the risk of recurrence in these women was not low enough to justify strongly recommending that they stop anticoagulants.
For women taking oestrogen therapy that the risk of recurrent VTE was low enough to justify strongly recommending that they stop anticoagulants, the study authors advised.
However they added: “When deciding if a patient with unprovoked VTE should receive indefinite anticoagulation, the expected absolute reduction in deaths from PE need to be carefully balanced with the expected increase in deaths from bleeding, and take into account the costs of treatment and the patient’s preferences.”