Incidence and risk factors of hemorrhagic events in essential thrombocythemia

Patients diagnosed with essential thrombocythemia (ET) experience thrombocytosis and risk reduction is therefore a key goal for therapeutic intervention. Currently, the main risk stratification model as recommended by the European LeukemiaNet is the International Prognostic Score of thrombosis in ET (IPSET-t); however, to date there has been no specific tool developed to aid in the prediction of hemorrhagic risk. Below, we summarize a publication from Tosoni et al. in Annals of Hematology on a retrospective analysis to define both the incidence and risk factors connected to hemorrhagic events in patients with ET.

Study design¹

• Included 308 ET patients diagnosed between 1996–2022
• The primary study endpoint was the incidence of thrombotic and hemorrhagic vascular events linked with possible correlations between associated clinical variables and their occurrence.

Results¹

Thrombotic events

• More patients experienced thrombotic events during the course of ET compared with diagnosis (10.4% vs 6.2%).
• More patients who experienced thrombosis had a high-risk IPSET-t score compared with patients who were high-risk but had no thrombosis at diagnosis (95% vs 47%, p < 0.001).
• No correlation was found between mutational status and thrombotic risk.

Hemorrhagic events

• A total of 40 hemorrhagic events were experienced by 35 patients.
• Risk of hemorrhagic event was increased:
  • in patients at an older age (≥60) at diagnosis by 2.5-fold after diagnosis vs younger patients (p = 0.032); and
  • in patients with a high-risk IPSET-t score by 4.2-fold after diagnosis vs low/intermediate risk (p = 0.003).
• The 10- and 20-year cumulative incidence of hemorrhagic events were 6% and 12%, respectively.
• Hemorrhage-free survival was lower in high-risk IPSET-t patients vs low/intermediate risk (p = 0.002).
• There was no correlation between incidence of hemorrhagic risk, driver mutation, and Janus kinase 2 variant allele frequency.