ABSTRACT
Polycythemia vera and essential thrombocythemia are chronic myeloproliferative disorders
characterized by a relatively benign clinical course that may be complicated by arterial
and venous thromboses. A thrombotic diathesis often manifests at diagnosis or in the
preclinical phase of the myeloproliferative disease. Peculiar microcirculatory disturbances
such as erythromelalgia and visual and hearing symptoms also commonly occur in these
patients, and are highly responsive to aspirin. In a placebo-controlled trial in relatively
low-risk polycythemic subjects, low-dose aspirin recently was shown to reduce the
incidence of both arterial and venous thrombosis with a limited increase of the hemorrhagic
risk. Due to its favorable benefit/risk profile, low-dose aspirin should be prescribed
to all patients with polycythemia vera who have no contraindication to this treatment.
Future studies should assess primarily the efficacy and safety of aspirin in essential
thrombocythemia, and test the possible use of more aggressive antithrombotic strategies
in high-risk polycythemic patients.
KEYWORDS
Polycythemia vera - essential thrombocythemia - aspirin - platelet activation - arterial
thrombosis - venous thrombosis
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Raffaele LandolfiM.D.
Institute of Internal Medicine, Haemostasis Research Center, Catholic University School
of Medicine
Largo Agostino Gemelli 8, 00168 Rome, Italy
eMail: rlandolfi@rm.unicatt.it