Prevalence and risk factors for Pulmonary Hypertension associated with chronic Myeloproliferative Neoplasms

Pulmonary hypertension (PH) is commonly reported in Philadelphia-chromosome negative myeloproliferative neoplasms (MPNs) including polycythemia vera (PV), essential thrombocythemia (ET), and myelofibrosis (MF). PH may be diagnosed directly by right heart catheterization (RHC) or estimated by transthoracic echocardiography (TTE). Survival is shortened by PH but despite the potential significance of PH to management and prognosis of MPN, estimates of its prevalence in MPNs vary and risk factors for the condition are poorly established. We performed a systematic review and meta-analysis of available studies to fill this void.

We searched EMBASE, MEDLINE, and Clinicaltrials.gov for the terms "pulmonary hypertension," "myeloproliferative disorders," "polycythemia vera," "essential thrombocythemia," and "myelofibrosis." We restricted analysis to the 1999-2019 window to improve uniformity of MPN diagnostic criteria. We retrieved 221 records and, after abstract and full-text screening, identified 17 papers meeting criteria for inclusion in our meta-analysis. A modified Newcastle-Ottawa scale was used to assess quality.

Results for 935 patients were available, 309 of these having PH (33%). Using logistic mixed-effect regression, we found that diagnosis mode (RHC vs TTE) and MPN duration influenced PH prevalence. Studies employing predominantly TTE yielded prevalence estimates ~5-fold higher than those using RHC (35% vs 7.2%). We identified MF and duration of MPN as significant risk factors for development of PH.

Prevalence of PH in MPNs is poorly understood with estimates ranging from 3.8% to 58%. Patients with MF and longer duration of disease seem at particularly high risk and should be carefully monitored for PH.