Pulmonary Hypertension and Mortality in Patients Awaiting Kidney Transplant: Cause for Concern and Potential Opportunity

BACKGROUND: Pulmonary hypertension (PH) is frequently reported in patients with advanced chronic kidney disease (CKD) and is associated with early allograft failure and death. However, the causes of PH are heterogeneous, and patient prognosis may vary by etiologic subtype. METHODS: Data from the UNC Cardiorenal Registry were examined to determine associations between pulmonary hypertension (PH), with or without elevated left atrial pressure (eLAP), and mortality in candidates for kidney transplantation. PH and eLAP were determined by Doppler echocardiography and by tissue Doppler imaging, respectively. RESULTS: From 2006-2013, 778 registry patients were screened preoperatively by echocardiography. Most patients were black (64%) and male (56%); the mean age was 56 years. PH was identified in 97 (12%) patients; of these, eLAP was prevalent in half. During a median follow up of 4.4 years, 179 (23%) received a kidney transplant, and 195 (25%) died. After adjustments for demographics, comorbidities, dialysis vintage and kidney transplantation, PH was associated with twice the 5-year mortality (HR = 2.11; 95% CI: 1.48 – 3.03), with stronger associations in the absence of eLAP (HR = 2.87; 95% CI: 1.83 – 4.49) than with eLAP (HR = 1.11; 95% CI: 0.57 – 2.17); P for interaction = 0.01. CONCLUSION: The mortality risk associated with PH among patients with advanced CKD appears to differ by etiology. Patients with PH in the absence of eLAP are at high risk of death and in need of focused attention. Future research efforts should investigate potential strategies to improve outcomes for these patients.