Characteristics and Outcomes of Lung Transplant Candidates With Preexisting Renal Dysfunction.

Background: The proportion of lung transplant candidates with comorbid renal dysfunction (RD) may rise as sicker patients are being considered for lung transplant (LT). There is lack of data regarding the characteristics and outcome of patients with RD and the role of simultaneous lung-kidney transplant (SLuKi) among these patients.

Methods: The United Network of Organ Sharing database was queried for adult patients (18 years or older) undergoing LT between 1995 and 2014. Pretransplant RD was defined as estimated glomerular filtration rate (eGFR), using the Chronic Kidney Disease Epidemiology Collaboration equation of <60 mL/min/1.73 m at the time of transplant listing. The recipient, donor, and procedure-related variables and survival were compared among patients with RD undergoing LT alone (split on the basis of eGFR impairment: 30-60 mL/min/1.73 m and ≤ 30 mL/min/1.73 m) vs those with SLuKi.

Results: The frequency of pretransplant RD was 5.42% (n = 1337). Patients with RD have significantly higher 1-year mortality (23.2% vs 15%; P < .001) and 3-year mortality (38.3% vs 28%; P < .001) than patients with eGFR > 60mL/min/1.73 m. The proportion of patients with RD undergoing SLuKi was 2.84% (38 of 1337). Both the number and proportion of patients undergoing SLuKi progressively increased during the study period, especially in the lung allocation score era (30 of 38 SLuKi patients in the post lung allocation score era (linear R = 0.641, P < .001). The patients who underwent SLuKi were significantly younger, had lower body mass index, serum albumin, and listing eGFR (P < .001 for all comparisons). Patients with SLuKi were more likely to have cystic fibrosis or vascular diseases as the underlying diagnosis (29.7% vs 13.8%, P = .004). Despite higher need of early dialysis support after transplant, there was no difference in the 30-day, 1-year, or 3-year survival between the 2 groups.

Conclusions: A significant proportion of LT candidates have a pre-existing RD, and this comorbidity is associated with significantly worse 1- and 3-year survival. Despite being the sicker group at baseline, patients with RD who undergo SLuKi have 1-year outcomes similar to patients with LT alone.