Impact of pulmonary hypertension on survival in patients with cystic fibrosis undergoing lung transplantation: an analysis of the UNOS registry.

Background: Pulmonary hypertension (PH) is a comorbidity reported in patients with cystic fibrosis (CF) with research limited to single-center studies.

Methods: To assess the impact of PH in patients with CF who received a lung transplant (LTx), the United Network for Organ Sharing was queried from 1987 to 2012, restricting analysis to transplant patients 6-55 years old between 1/1/2005 and 7/6/2011.

Results: Of 23,951 lung transplants, 1177 met inclusion criteria with 831 having mean pulmonary artery pressure (mPAP) data available. For the entire cohort, mean age was 30.3 (SD=9.2, range 12-55), and mean mPAP was 26.5 (SD = 7.8, range 5-66) mmHg. A total of 470 (57%) had PH defined as mPAP ≥ 25 mmHg. Comparing PH to non-PH groups, mean forced expiratory volume in one second (FEV1) was 24.4 (SD = 13.8) vs. 26 (SD=13.9) % of predicted, mean supplemental oxygen requirement at rest was 4.5 (SD = 4.1) vs. 3.7 (SD = 3.0) liters per minute, and mean lung allocation score was 49 (SD = 16) vs. 43 (SD = 12), respectively. For the PH group, median survival was 84.4 months compared to 67.1 months for the non-PH group (log-rank p-value = 0.326). The adjusted hazard ratio for PH vs. non-PH was 0.862 (95% CI: 0.653-1.138; p = 0.293), thus indicating no statistically significant effect of PH on survival.

Conclusions: A high prevalence of PH was found in CF patients prior to LTx. Based on our models despite PH being prevalent, there is no strong evidence suggesting that it significantly alters the risk of death in CF patients after LTx.