The landscape of referrals for lung transplantation in pulmonary arterial hypertension: A report from the Pulmonary Hypertension Association Registry

Background: Early referral for lung transplantation in patients with pulmonary arterial hypertension (PAH) is recommended by multiple professional societies. We sought to use the Pulmonary Hypertension Association Registry (PHAR) to describe the current landscape of referrals for lung transplantation in patients with PAH. Methods: PHAR is a 72-center US-based registry of patients with PAH. Participants were followed longitudinally with repeat assessments of clinical parameters, including referrals for transplantation. We compared clinical parameters between those referred for transplantation at any point, with those never referred. Next, we tested whether various clinical parameters predicted time to referral, using cox-proportional hazards modeling and stepwise backward elimination. Results: Of 1,671 participants analyzed with 4,607 person-years of follow up, 199 (12%) were referred for transplantation. Of those referred, 30% underwent transplantation and 21% died without transplantation. Only 18–29% of participants with functional class 4 disease, registry to evaluate early and long-term PAH disease management Lite 2 high-risk disease, or 2022 European Society of Cardiology/European Respiratory Society (ESC/ERS) high-risk disease were referred for transplant. Rates of referral did not increase in sensitivity analyses restricting the cohort to participants without obvious contraindications based on body mass index or age. In multivariate modeling accounting for death as a competing risk, a diagnosis of pulmonary veno-occlusive disease, higher registry to evaluate early and long-term PAH disease management Lite 2 Scores, and parenteral prostacyclin use were associated with increased likelihood of referral, while older age and higher body mass index were associated with decreased likelihood of referral. Conclusion: Rates of referral for lung transplantation in patients with PAH remain unacceptably low and occur too late. Increased awareness of the benefit of early referral is necessary, even at expert centers.