Evaluation of arterial compliance in polycythemia vera patients: short and long-term influence of phlebotomy.

Background: Thrombosis is a major cause of morbidity and mortality in polycythemia vera. Hypercoagulability is principally due to hyperviscosity of the whole blood, an exponential function of the hematocrit. PV is also associated with endothelial dysfunction that can predispose to arterial disease.