“…However, a certain proportion of patients fail to respond adequately to medical therapy and surgical intervention, either balloon atrial septostomy or lung transplantation, is necessary. In his report, HOEPER [29] describes the case of a young female with idiopathic PAH who, despite an initially good response to monotherapy and then sequential combination therapy, rapidly deteriorated. She developed right heart failure with renal failure and lactic acidosis within 48 h of hospital admission and her only hope was lung transplantation.…”