Case Report: Chronic Thromboembolic Pulmonary Hypertension Postsplenectomy in Hereditary Spherocytosis

Abstract

SESSION TITLE: Pulmonary Vascular Disease SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: Chronic thromboembolic pulmonary hypertension (CTEPH) is an uncommon but well-recognized cause of pulmonary hypertension.1 CTEPH is characterized by intra-luminal thromboembolism and subsequent arterial stenosis after recanalization. Splenectomy carries an increased risk of CTEPH development.2 CASE PRESENTATION: A 43 year old male with a history of hereditary spherocytosis (HS) status-post splenectomy and narcolepsy was admitted for dyspnea and syncope. He denied prior history of deep vein thrombosis or pulmonary embolism. Home medications were significant for an 8 year use of amphetamine-dextroamphetamine. Pertinent physical exam findings included jugular venous distention and a prominent S2 on cardiac auscultation. Labs were significant for polycythemia (hemoglobin 18.3 g/dl), normal platelets, and a brain natriuretic peptide level of 2200 pg/ml. Computed tomography scan for pulmonary embolism was negative. Transthoracic echocardiogram suggested pulmonary hypertension, with a normal left ventricular ejection fraction. Cardiac MRI depicted severe right ventricular dilation and dysfunction. Right heart catheterization revealed mean pulmonary artery pressure of 55 mmHg, pulmonary capillary wedge pressure of 7 mmHg, a cardiac index of 2.2, and a pulmonary vascular resistance of 1012 dyn*s/cm5. Ventilation/perfusion scan showed large perfusion mismatched defects, confirming the diagnosis of CTEPH (Figure 1). Prothrombotic workup was unrevealing. The treatment plan included a referral for pulmonary thromboendarterectomy. DISCUSSION: Splenectomy and hereditary spherocytosis have been associated with a 20 fold increased risk of CTEPH.2 The link between splenectomized spherocytosis patients and CTEPH remains undetermined.1 Theories include the involvement of prothrombotic, abnormal erythrocytes allowed to circulate due to the loss of splenic filtration. Thrombocytosis may also cause a prothrombotic state in these patients. Finally, scavenging of nitric oxide by free heme due to intravascular hemolysis may result in vasoconstriction and endothelial damage.2 Important aspects of therapy include anticoagulation and surgery. Confounding this case, amphetamines such as those taken by this patient for narcolepsy have been associated with an increased risk of pulmonary hypertension.3 CONCLUSIONS: Although CTEPH is rare, it should be considered in patients with prior splenectomy presenting with symptoms consistent with pulmonary hypertension, especially if they have underlying hematologic disease. Reference #1: Hoeper MM, Mayer E, Simonneau G, Rubin LJ. Chronic thromboembolic pulmonary hypertension.Circulation. 2006 Apr 25;113(16):2011-20. Reference #2: Jaïs X, Ioos V, Jardim C, Sitbon O, Parent F, Hamid A, Fadel E, Dartevelle P, Simonneau G, Humbert M. Splenectomy and chronic thromboembolic pulmonary hypertension. Thorax. 2005 Dec 1;60(12):1031-4. Reference #3: Chin KM, Channick RN, Rubin LJ. Is methamphetamine use associated with idiopathic pulmonary arterial hypertension?. Chest.2006;130(6):1657-63. DISCLOSURE: The following authors have nothing to disclose: Nisha Crouser, Avraham Cooper, Samuel Jersak No Product/Research Disclosure Information