Pulmonary hypertension is associated with increased post-lung transplant mortality risk in patients with chronic obstructive pulmonary disease

Abstract

Background: Pulmonary hypertension associated with lung disease (PHLD) has been shown to be a predictor of disease severity and survival in patients awaiting lung transplantation. Little is known about the relationship of PHLD and survival after lung transplantation or how this may vary by disease. This study evaluated the effect of PHLD on 1-year survival after lung transplantation for patients with the 3 most common indications for transplantation: chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), and cystic fibrosis (CF).

Methods: Organ Procurement and Transplantation Network data were obtained for all lung transplant recipients who received an allograft between May 2005 and June 2010. The relationship between PHLD and 1-year survival after lung transplantation for each diagnostic group was examined with Kaplan-Meier estimates and Cox regression. Covariates included in the model were those defined in the current Lung Allocation Score system post-transplant survival model, including age, serum creatinine, percentage predicted forced vital capacity, functional status, and mechanical ventilation use at time of transplant. The estimated relative risk was calculated using Poisson regression with robust error variance and adjustment for covariates.

Results: Sample sizes for COPD, IPF, and CF patients were 2,025, 2,304, and 866, respectively. The 1-year post-transplant survival for COPD patients with PHLD was 76.9% vs 86.2% for COPD patients without PHLD (p = 0.001). In multivariate Cox regression analysis COPD patients with PHLD had a 1.74 (95% confidence interval, 1.3-2.3) times higher risk of 1-year post-transplant mortality (p = 0.001). Similar analyses for IPF and CF diagnostic groups showed no significant difference in survival between patients with and without PHLD.

Conclusions: COPD patients with PHLD have increased post-transplant 1-year mortality. No significant difference was seen in patients with IPF or CF. Further studies to evaluate the potential mechanisms for this difference between diagnoses are needed.

Keywords: Pulmonary hypertension associated with lung disease; chronic obstructive pulmonary disease; cystic fibrosis; idiopathic pulmonary fibrosis; lung transplantation; survival.