The role of extracorporeal life support in the management with severe idiopathic pulmonary artery hypertension undergoing lung transplantation: are those patients referred too late?

Idiopathic pulmonary artery hypertension (iPAH) is a clinical condition characterised by pre-capillary pulmonary hypertension (i.e., pulmonary capillary wedge pressure ≤15 mmHg) at right heart catheterisation. iPAH may be idiopathic, heritable, induced by drug or toxin exposure, or develop as a consequence of different disorders, such as connective tissue diseases, HIV infection, congenital heart diseases or portal hypertension (1). The estimated prevalence of iPAH is ≤15–50 patients per one million of the population (2,3). According to the National Institutes of Health (NIH) in the United States, pulmonary hypertension was associated with an overall survival for iPAH patients of 2.8 years (4). Conventional management of iPAH, apart from general measures to help alleviate symptoms, include oral anticoagulants, diuretics and oxygen; while the targeted therapies that developed in in recent decades act on prostacyclin, endothelin, and nitric oxide pathways to improve endothelial dysfunction (5,6). Patients who fail to improve or show clinical worsening despite maximal medical therapy, have a very poor prognosis and should routinely be assessed for lung transplantation (LTx) (5). iPAH forms one of the less common indications for LTx comprising 3% of all indications (7). It has already been shown that increasing pulmonary artery pressure, while awaiting LTx, is associated with worse long-term survival following LTx (8). Primary graft dysfunction (PGD) is the main cause of early morbidity and mortality after LTx and iPAH is one of the major risk factors for PGD (9). Extracorporeal life support (ECLS) is rarely utilized in patients with severe iPAH as a bridge to LTx or as a rescue in PGD following LTx for iPAH while being the only possible rescue therapy for this demanding patient cohort. In this respect, we evaluated the utility of ECLS in the management of severe iPAH for a patient cohort undergoing LTx in our institution