Risk Factors for Arterial, Venous Thrombosis Differ in Polycythemia Vera
The most common type of venous thrombosis is a deep vein thrombosis, a blood clot in the veins of the leg.
History of thrombotic events is the most predictive risk factor for arterial and venous thrombosis among patients with polycythemia vera (PV), according to a study published in the Blood Cancer Journal.
Patients with PV frequently experience thrombotic complications — a cause of significant morbidity and mortality in this patient population — yet risk factors predicting venous and arterial thrombosis have not been fully elucidated.
For this study, researchers assessed the outcomes of 587 patients with PV. Sixty-four percent of patients were considered high risk (older than 60 years and/or history of prior thrombosis), and many had additional cardiovascular risk factors including hypertension, diabetes, hyperlipidemia, and history of active or infrequent smoking. Most patients had JAK2 mutation-positive disease (99%), with 18% and 11% of patients characterized with the non-driver TET2 and ASXL1 mutations, respectively.
After a median follow-up of 102 months, thrombotic events occurred in 22% (128) of patients, of which 14% (82) were arterial and 10% (57) were venous events.
A multivariate analysis revealed that the significant predictors of subsequent arterial events were prior arterial events, hyperlipidemia, and hypertension.
Factors that were the most significant predictors of subsequent venous events were prior venous events, leukocytosis, and major hemorrhage.
Other significant associations with arterial thrombosis included advanced age (60 years and older), diabetes, hyperlipidemia, hypertension, and normal karyotype, and venous thrombosis was associated with younger age (younger than 60 years), female sex, history of major hemorrhage, and palpable splenomegaly.
Neither the TET2 nor ASXL1 nondriver mutations were found to be predictive of thrombotic events.
Results of the study demonstrated that a history of thrombosis is critical in predicting future cardiovascular events among patients with PV, and that arterial and venous thrombosis are distinct pathologies with differing risk factors. The authors concluded that “further studies are needed to conclusively confirm the role of specific risk factors identified for arterial vs venous thrombosis.”
ReferenceCerquozzi S, Barraco D, Lasho T, et al. Risk factors for arterial versus venous thrombosis in polycythemia vera: a single center experience in 587 patients [published online December 27, 2017]. Blood Canc J. doi: 10.1038/s41408-017-0035-6