Eisenmengers Syndrome Managed With Inhaled Prostacyclin

Abstract

INTRODUCTION: Atrial septal defect( ASD) is the second most common congenital heart defect in adults, causing shunting and severe fixed pulmonary artery hypertension (PAH). We present a patient with Eisenmenger’s syndrome, who underwent percutaneous closure and was successfully treated with inhaled prostacyclin. CASE PRESENTATION: A 42 year old man with atrial flutter presented with progressive dyspnea for two weeks. Physical examination revealed a systolic murmur at the left sternal margin and pitting edema of all extremities. Chest x ray revealed bilateral lung infiltrates. CT of the chest was suggestive of PAH and chronic fibrosis. Transthoracic echocardiogram showed a 1.3 cm ASD (ostium secundum) with bidirectional flow. Over the next twelve hours, the patient developed acute hypoxemic respiratory failiure on BiPAP and required intubation. He remained hypoxemic despite 80% FiO2, so right heart catheterization( RHC) was performed and confirmed severe PAH with elevated pulmonary vascular resistance (PVR) and preserved LV function. Due to persistent hypoxemia despite increasing positive end expiratory pressure(PEEP) to 12cm H20, intravenous(IV) epoprostenol was initiated. Bronchoalveolar lavage was negative for infection, and endobronchial biopsy was negative for granuloma or tumor. Hypoxemia worsened on IV epoprostenol, and cardiology was consulted for closure of the ASD, which was performed successfully using an Amplatzer septal occlusion device. After closure of the ASD, the patient continued to have very high FiO2 and PEEP requirements. Inhaled prostacyclin was then added to improve ventilation/perfusion (V/Q) match, and steady improvement in oxygenation was noted. Repeat RHC showed significant improvement in pulmonary hypertension, and the patient was eventually weaned from the ventilator and discharged on home oxygen DISCUSSION: Pulmonary hypertension in patients with Eisenmenger syndrome is associated with a neurohormonal imbalance of pulmonary vasodilators and vasoconstrictors. This imbalance leads to vascular remodeling, intimal fibrosis, and increased PVR. In the management of patients with Eisenmenger syndrome, prostacyclin therapy improves hemodynamics (decrease in mean PA pressure, improvement in cardiac index, and decrease in PVR) and improves exercise capacity. CONCLUSIONS: This case supports the concept that IV epoprostenol worsens hypoxemia in PAH by non specific vasodilation of pulmonary vasculature leading to V/Q impairment whereas inhaled prostacyclin is more selective and is superior to systemic therapy. Additionally, maintenance of inter-atrial communication provides a mechanism to decompress the right ventricle and is thought to be advantageous in Eisenmengers syndrome. Our patient, however, underwent closure, yet had a successful outcome.