Current prediction models appear to overestimate survival for patients with pulmonary arterial hypertension who are awaiting lung transplant, according to data presented at the International Society for Heart and Lung Transplantation Annual Meeting and Scientific Sessions.
Before 2005, lung transplant priority was based on wait time. In 2005, the Lung Allocation Score was developed with the goal of awarding transplant priority based on need, according to background information from the study.
Researchers reviewed past and current models of predicting survival for patients with pulmonary arterial hypertension (PAH) awaiting lung transplant. Data on 1,027 patients with PAH listed for lung or heart/lung transplantation since 1991 from the Scientific Registry of Transplant Recipients were analyzed. Overall survival was estimated using Kaplan-Meier curves and was compared with predicted survival from the Pulmonary Hypertension Connection and French equations, both of which were developed to predict survival in this patient population. Survival estimates were repeated for patients listed before and after Jan. 1, 2006, to account for introduction of the Lung Allocation Score, according to the abstract.
Among 409 PAH patients listed for lung transplant after Jan. 1, 2006, 72% were alive at 1 year, compared with the Pulmonary Hypertension Connection risk equation which predicted survival at 92%.
According to the researchers’ findings, current prediction models, including the Pulmonary Hypertension Connection and French equations, underestimate survival for PAH patients listed prior to 2006 and overestimate survival for those listed after 2006.
“Although treatment for PAH has improved, long-term survival, even with therapy, is disappointing,” Mardi Gomberg-Maitland, MD, director of pulmonary hypertension at the University of Chicago, said in a press release. “We set out to determine if existing survival models for PAH are accurate predictors. In the end, a new equation was needed to better predict survival in PAH patients on the waiting list. Greater attention should be drawn to the possibility of separation in listing procedures for these patients.”
For more information:
Gomberg-Maitland M. Abstract #363. Presented at: International Society for Heart and Lung Transplantation Annual Meeting and Scientific Sessions; April 24-27, 2013; Montreal.
Disclosure:Gomberg-Maitland reports no relevant financial disclosures.