Severe pulmonary arterial hypertension: treatment options and the bridge to transplantation.

Pulmonary arterial hypertension (PAH) is a rare disease leading to right heart failure and death. Prognosis remains poor, particularly for patients with severe disease, i.e. World Health Organization functional class IV. There have been significant improvements in treatment options. Several agents are available that target the three main established PAH disease pathways, and can be combined sequentially or upfront. Strong scientific evidence supports the use of intravenous epoprostenol in severe PAH; however, despite recommendations, many patients do not receive parenteral prostanoids and there is a lack of evidence from randomised clinical trials supporting the value of other PAH medications alone in severe PAH. Lung transplantation is an important option in patients with severe PAH who have not responded sufficiently to therapy, or who have worsened despite maximal treatment. Bridging techniques are available for patients who worsen while awaiting transplantation. The type of bridging technique used depends on various factors including patient illness severity, physician experience and the anticipated waiting time for transplantation. With the aim to facilitate the treatment decision-making process, herein we review the medical treatment options available for patients with severe PAH, and the bridging techniques that may be used to sustain patients awaiting transplantation.