Estimates of the prevalence of pulmonary hypertension (PH) as a complication of myeloproliferative neoplasms (MPNs) vary broadly, according to a systematic review and meta-analysis that was recently published in the European Journal of Haematology.
PH is linked to a higher MPN disease burden and poorer survival, but little has been known about the prevalence and factors associated with PH in MPNs, according to the study investigators.
The investigators performed searches of EMBASE, MEDLINE, and ClinicalTrials.gov databases for studies involving pulmonary hypertension, myeloproliferative disorders, polycythemia vera, essential thrombocytopenia, and/or myelofibrosis (MF) dated between 1999 and 2019. The goal was to assess the prevalence of, and risk factors associated with, PH in patients with MPNs, in addition to patient characteristics and outcomes.
The searches identified 221 records, of which 17 reports met criteria for inclusion. Results for 935 patients were found, of whom 309 had PH. The prevalence of PH varied greatly across studies; PH prevalence was less than 5% in 3 studies, 11% to 14% in 3 studies, and greater than 36% in 7 studies. The prevalence of pulmonary hypertension could not be evaluated in analyses that only included patients with pulmonary hypertension, of those that were case control studies in which pulmonary hypertension was an exposure variable; therefore, 13 of the 17 reports were used as “prevalence sets” that investigated the factors that affected the prevalence of pulmonary hypertension at a study level.
Mode of diagnosis showed an association with reported PH prevalence. Compared with transthoracic echocardiography (TTE) as the mode of diagnosis, the odds ratio (OR) for PH diagnosis using right heart catheterization (RHC) was 0.1 (95% CI, 0.01-0.9).
Age and duration of MPN were identified as significant risk factors for PH, as was the presence of MF. Compared with a diagnosis of polycythemia vera, a diagnosis of MF had a more than 2-fold association with risk of PH (OR, 2.6; 95% CI, 1.36-4.8). Primary MF and secondary MF were both more highly associated with PH than was polycythemia vera.
“Our analysis points to the need for prospective cross-sectional data sets broadly representative of patients of different ages, MPN diagnoses and duration of MPN,” wrote the study investigators in their report.
The investigators recommended that TTE be more broadly used for screening, with RHC reserved for select patients. They also stated that future studies should include a diagnostic approach that clarifies which patients should receive more or less invasive testing, in order to more accurately establish the rate of PH and its pathophysiology.
Ferrari A, Scandura J, Masciulli A, Krichevsky S, Gavazzi A, Barbui T. Prevalence and risk factors for pulmonary hypertension associated with chronic myeloproliferative neoplasms. Eur J Haematol. Accepted manuscript. Published online November 1, 2020. doi:10.1111/ejh.13543