Unexplained pulmonary hypertension in chronic myeloproliferative disorders

Aim: To investigate the potential association between the chronic myeloid disorders (CMDs), including the chronic myeloproliferative disorders, and pulmonary hypertension (PH). Methods: Retrospective chart review of patients who had received diagnoses of both CMD and PH. Patients with a known cause of PH were excluded. The diagnosis of a CMD was based on established criteria. The diagnosis of PH was based on echocardiographic data or right heart catheterization data. Results: Twenty-six patients satisfied the criteria for both a CMD and PH. Twelve patients had myeloid metaplasia with myelofibrosis (MMM), 5 patients had essential thrombocythemia (ET), 6 patients had polycythemia vera, 2 patients had a myelodysplastic syndrome, and 1 patient had chronic myeloid leukemia. Twenty-two patients (92%) received treatment for their CMDs, which included therapy with hydroxyurea (18 patients), anagrelide (7 patients), and busulfan (3 patients). PH was diagnosed a median of 8 years after recognition of the CMD (range, 0 to 26 years). The median right ventricular systolic pressure (RVsys) was 71 mm Hg (range, 32 to 105 mm Hg). RVsys correlated with the platelet count in patients with MMM (r = 0.30) and ET (r = 0.6) and with the hemoglobin levels in patients with PV (r = 0.77). Treatment of CMD did not seem to affect the severity of the pulmonary artery pressures as measured by serial echocardiography. With a median survival time of 18 months after the diagnosis of PH, the cause of death in the majority of the patients was cardiopulmonary. Conclusions: The current study suggests a higher than expected incidence of PH in patients with MMM, PV, and ET. Prognosis in such a setting is poor and may not be influenced by aggressive treatment of the underlying hematologic disorder.