Managing thrombotic risk in myeloproliferative disorders

INTRODUCTION: Myeloproliferative neoplasms (MPNs) are clonal hematopoietic stem cell disorders associated with arterial and venous thrombosis. Thrombotic risk reflects conventional vascular factors and disease-specific thromboinflammatory biology. Thrombosis remains a major cause of morbidity and mortality in MPNs despite contemporary guidelines. Thus, there remains a challenging therapeutic uncertainty across diverse clinical presentations. AREAS COVERED: We reviewed PubMed-listed articles on the epidemiology, mechanisms, risk stratification and clinical management of thrombosis in classical Philadelphia-negative MPNs. We discuss evidence for aspirin, hematocrit control, cytoreduction and anticoagulation choice. We also examine management in special populations such as in pregnancy and frailty. Lastly, we give an overview on the emerging use of Direct oral anticoagulants (DOACs) in unusual site thrombosis in this setting. EXPERT OPINION: Thrombosis in MPNs should not be treated as a single entity. Arterial, venous and unusual-site events all differ in biology and this can have therapeutic implications. Future progress requires personalized strategies that balance thrombosis prevention, bleeding risk and clonal disease control in a heterogenous group.