Ahlstrand E, Samuelsson J, Lindgren M, et al. - Researchers undertook this case-control study nested within the Swedish MPN registry, to determine the relative value of risk factors, treatments and blood counts for the occurrence of vascular complications as well as their influence on life expectancy in Essential Thrombocythemia (ET) and Polycythemia Vera (PV). They compared 71 ET and 81 PV cases with vascular complications vs matched controls. In ET and PV, the respective incidence of vascular complications was estimated to be 2.0 and 3.4 events per 100 patient-years, respectively. Cases and controls exhibited no significant risk factor variations at diagnosis in neither of the diseases. In both ET and PV, a high risk of vascular complications was observed. Life expectancy was considerably affected by these complications. In PV, antithrombotic and cytoreductive therapy conferred a protective effect for vascular complications and this emphasizes the significance of avoiding undertreatment.