Risk factors for death of patients with cystic fibrosis awaiting lung transplantation.

Abstract

The optimal timing for listing of cystic fibrosis patients for lung transplantation is controversial. We conducted a retrospective cohort study of 343 patients listed for lung transplantation at four academic medical centers to identify risk factors for death while awaiting transplantation. Data on possible risk factors were abstracted from medical records. Time to death, patient demographic characteristics, and risk factors for death while awaiting transplantation were assessed. Univariate and multivariate survival analyses were performed using Cox regression. By univariate analyses, FEV1 < or = 30% predicted (HR, 3.8; 95% CI, 2.0-7.5), Pa(CO2) > or = 50 mm Hg (HR, 1.85; 95% CI, 1.1-3.0), and shorter height (HR, 1.8; 95% CI, 1.1-3.0) were associated with a higher risk of death. Referral from an accredited cystic fibrosis center was associated with a lower risk (HR, 0.53; 95% CI, 0.30-0.92). The final multivariate model included referral from an accredited cystic fibrosis center (HR, 0.5; 95% CI, 0.3-1.0) and listing year after 1996 (HR, 0.4; 95% CI, 0.2-0.7); both were associated with a lower risk of death. FEV1 < or = 30% predicted (HR, 6.8; 95% CI, 2.4-19.3), Pa(CO2) > or = 50 mm Hg (HR, 6.9; 95% CI, 1.5-32.1), and use of a nutritional intervention (HR, 2.3; 95% CI, 1.3-4.1) were associated with increased risk. Patients with FEV1 > 30% predicted had a higher risk of death only when their Pa(CO2) was > or = 50 mm Hg (HR, 7.0; 95% CI, 1.5-32), while the increased risk of death with FEV1 < or = 30% was not further influenced by the presence of hypercapnia. We identified risk factors for waiting list mortality that could impact on transplant listing and allocation guidelines.