Impact of age and time since diagnosis on thrombosis risk in MPN: A Swedish matched-cohort study

Thrombosis and hemorrhagic complications are primary manifestations of myeloproliferative neoplasms (MPN), contributing to increased morbidity and mortality. Although older age is an established thrombosis risk factor, the role of time since diagnosis and age remain unclear. 

Batyrbekova et al. published a Swedish register-based matched-cohort study investigating the impact of age and time since diagnosis on thrombosis risk in patients with MPN in the British Journal of Hematology.

The study cohort included patients with polycythemia vera (n = 7,071), essential thrombocythemia (n = 6,735), primary myelofibrosis (n = 1,132), and MPN unclassifiable (n = 2,892), along with matched controls (n = 172,634). Approximately 25% of patients in the MPN cohort and 12% of matched controls had prior thrombosis.

Key learnings

Increasing attained age was associated with high rates of thrombosis in both patients with MPN and matched controls, though the MPN cohort experienced significantly higher rates of thrombosis.

In the MPN cohort, the highest rates of thrombosis were observed during the first 2 years post-diagnosis, but were then dependent on attained age compared with time since diagnosis. 

At 5 years, the HR for any thrombosis in the MPN cohort vs matched controls was 1.79 (95% CI, 1.65–1.94) at age ≥65 years, 1.51 (95% CI, 1.41–1.62) at age ≥75 years, and 1.46 (95% CI, 1.36–1.56) at age ≥85 years.

The population-based study highlights the importance of age and early interventions to optimize care in MPN. The findings provide a basis for the development of targeted interventions to prevent thrombosis in patients with MPN.