PULMONARY HYPERTENSION IN ESSENTIAL THROMBOCYTOSIS: IS HYDROXYUREA A POTENTIAL TREATMENT? A CASE REPORT

Abstract

SESSION TITLE: Monday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/21/2019 02:30 PM - 03:15 PM INTRODUCTION: Essential thrombocytosis is a myeloproliferative disorder which is associated with group 5 pulmonary hypertension (PH). PH is uncommonly prevalent in patients with myeloproliferative disease. Here we present a case of essential thrombocytosis with elevated right ventricular systolic pressures that showed significant improvement with initiation of hydroxyurea. CASE PRESENTATION: 79 year old Caucasian female with past medical history of chronic obstructive pulmonary disease , paroxysmal atrial fibrillation, essential thrombocytosis who initially presented with shortness of breath. Physical examination revealed decreased bilateral air entry, with a loud pulmonary component of the second heart sound and a grade 2 systolic ejection murmur in the left lower sternal border. Laboratory studies revealed a platelet count of 1,368 x 103/cumm. Initial admission echocardiogram confirmed the physical findings revealing severe tricuspid regurgitation and severe pulmonary hypertension with right ventricular systolic pressure(RSVP) of 94 mm Hg. The interventricular septum was flattened , consistent with right heart pressure overload. A previous echocardiogram done 5 years ago demonstrated mild pulmonary hypertension with RVSP of 45 mmHg and mild tricuspid regurgitation. Computed tomography pulmonary angiogram performed during the admission did not show any significant pulmonary vascular pathology. Patient had discontinued hydroxyurea as an outpatient on her own due to a non-healing ankle ulcer. She was restarted on hydroxyurea and discharged on the same. Patient was readmitted two months later with cough and worsening expectoration, low-grade fever and was treated for an exacerbation of her underlying chronic obstructive pulmonary disease. A repeat echocardiogram performed during this admission for concerns of worsening pulmonary hypertension showed a significant improvement in pulmonary hypertension with right ventricular systolic pressure of 60 mmHg. Platelet count also improved to 389 x 103/cumm. DISCUSSION: We suspect pulmonary hypertension can have a significant impact on morbidity and mortality in patients with myeloproliferative disorder. One of the studies revealed an incidence of pulmonary hypertension in about 47.8%(1 )in patients with essential thrombocytosis. Pulmonary hypertension is often asymptomatic (1,2,3 )in these patients and treatment modalities have not been identified and established. The beneficial effect of hydroxyurea could be just due to its effect on underlying myeloproliferative disease by inactivating ribonucleotide reductase and inhibiting DNA synthesis causing cell death or via a alternate mechanism which needs to be studied at this point(4). CONCLUSIONS: The case report emphasizes the need for early evaluation of PH in myeloproliferative disorder. There is also a need for further studies regarding the use of hydroxyurea as a treatment modality for such cases. Reference #1: 1. Altintas A, Karahan Z, Pasa S, et al. Pulmonary hypertension in patients with essential thrombocythemia and reactive thrombocytosis. Leuk Lymphoma 2007;48(10):1981–1987. Reference #2: 2. Kadikoylu G, Onbasili A, Tekten T, Barutca S, Bolaman Z. Functional and morphological cardiac changes in myeloproliferative disorders (clinical study). Int J Cardiol 2004;97(2):213–220. Reference #3: 3. Dingli D, Utz JP, Krowka MJ, Oberg AL, Tefferi A. Unexplained Pulmonary Hypertension in Chronic Myeloproliferative Disorders. CHEST 2001;120(3):801–808. 4. Yarbro JW. Mechanism of action of hydroxyurea. Semin Oncol 1992 Jun;19(3 Suppl 9):1-10 DISCLOSURES: No relevant relationships by Shaylika Chauhan, source=Web Response No relevant relationships by Akhilesh Kumar Khuttan, source=Web Response No relevant relationships by Arjun Madhavan, source=Web Response No relevant relationships by Shalini Tripathi, source=Web Response