December 2024
Patients diagnosed with myeloproliferative neoplasms (MPNs) — including polycythemia vera (PV), essential thrombocythemia (ET), and myelofibrosis (MF) — are at a higher risk of both venous and arterial thromboembolism. Management of thrombosis is central to the care of these patients; however, there is a dearth of recommendations specific to MPNs on the duration and selection of anticoagulation for the management of these events.1
In this edition of Drawing First Blood, ASH Clinical News invited Chi-Joan How, MD, clinical chief of hematology at Brigham and Women’s Faulkner Hospital and assistant professor in medicine at Harvard Medical School in Boston, and Brady L. Stein, MD, professor of medicine at Northwestern University’s Feinberg School of Medicine in Chicago, to debate and discuss how long a patient with an MPN should be treated with anticoagulation and other factors to consider when determining the appropriate management of thrombosis. Dr. How was asked to argue for indefinite anticoagulation therapy; Dr. Stein was assigned to argue for limited-duration anticoagulation therapy.’
Chi-Joan How, MD Brady L. Stein, MD
What are the benefits and risks of indefinite anticoagulant therapy?
Chi-Joan How, MD: Anytime someone is on anticoagulation, we are trying to reduce the risk of thrombosis and balance that against the risk for bleeding. MPNs create a procoagulant state, so patients are at a higher risk of thrombosis. Patients with an MPN who had a prior thrombosis are at an especially high risk for recurrence, up to 10% per year in some patients.
The anticoagulant should be effective for however long someone is on it, but once they stop, there is a risk of thrombotic recurrence. Because patients with an MPN have a higher ongoing risk of subsequent blood clots, staying on the blood thinner can help prevent these events, such as pulmonary embolism (PE), deep vein thrombosis (DVT), or blood clots in the splanchnic venous system.
The risk of indefinite anticoagulant therapy is bleeding. We know that patients with an MPN also have more bleeding issues. We know, for instance, that patients with ET who have a very high platelet count might be predisposed to bleeding rather than thrombosis. A blood thinner would add to this bleeding risk.
Finally, a lot of patients might not want to be on indefinite treatment. Even though it may seem like a small matter, one benefit of a finite duration of anticoagulation is that it is one fewer medication a patient has to take.