Vascular and neoplastic risk in a large cohort of patients with polycythemia vera.
OBJECTIVE
The clinical course of polycythemia vera is often complicated by thrombosis as well as by the possible transition to myeloid metaplasia with myelofibrosis or acute myeloid leukemia. The aim of this study was to assess the rate of these complications in subjects receiving currently recommended treatments.


METHODS
Overall, 1,638 patients from 12 countries were enrolled onto a large, prospective multicenter project aimed at describing the clinical history of polycythemia vera for the following outcomes: survival, the cumulative rate of cardiovascular death and thrombosis, the cumulative rate of leukemia, myelodysplasia, and myelofibrosis. The mean duration of the disease at entry and the duration of the follow-up were 4.9 and 2.7 years, respectively.


RESULTS
The overall mortality rate of 3.7 deaths per 100 persons per year resulted from a moderate risk of cardiovascular death and a high risk of death from noncardiovascular causes (mainly hematologic transformations). Age older than 65 years and a positive history of thrombosis were the most important predictors of cardiovascular events. Antiplatelet therapy, but not cytoreductive treatment, was significantly associated with a lower risk of cardiovascular events. We found a consistent association between age and risk of leukemia, and between duration of the disease with risk of myelofibrosis.


CONCLUSIONS
The European Collaboration on Low-Dose Aspirin in Polycythemia Vera study documents that large international collaborative studies are feasible in this field, in which few epidemiologic data are available. The persistently high mortality rate from hematologic malignancies characterizes the unmet therapeutic need of polycythemic patients and suggests a priority for future studies in this disease.
Marchioli
Roberto
R
European Collaboration on Low-Dose Aspirin in Polycythemia Vera Coordinating Centre, Consorzio Mario Negri Sud, Via Nazionale, 66030 Santa Maria Imbaro, Italy. marchioli@negrisud.it
Finazzi
Guido
G
Landolfi
Raffaele
R
Kutti
Jack
J
Gisslinger
Heinz
H
Patrono
Carlo
C
Marilus
Raphael
R
Villegas
Ana
A
Tognoni
Gianni
G
Barbui
Tiziano
T
D000368:Aged; D002318:Cardiovascular Diseases / Q000209:etiology* / Q000401:mortality*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007938:Leukemia / Q000209:etiology* / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D011087:Polycythemia Vera / Q000150:complications* / Q000628:therapy*; D011446:Prospective Studies; D012307:Risk Factors; D016019:Survival Analysis; D013927:Thrombosis / Q000209:etiology* / Q000401:mortality*; D013997:Time Factors