Pulmonary arterial hypertension in patients with chronic kidney disease on dialysis and without dialysis: Results of the PEPPER-study

Background: Pulmonary hypertension (PH) is common in patients with dialysis-dependent chronic kidney disease (CKD) and is an independent predictor of mortality. However, specific hemodynamics of the pulmonary circulation, changes induced by hemodialysis and prevalence of pulmonary arterial hypertension (PAH) have not been evaluated in patients with CKD. Methods and results: We assessed consecutive patients with CKD on hemodialysis (group 1, n=31) or without dialysis (group 2, n=31), in World Health Organization functional class ≥II with dyspnea unexplained by other causes, using right heart catheterization (RHC). In group 1 RHC was performed before and after dialysis. PAH was diagnosed if mean pulmonary arterial pressure (mPAP) was ≥25 mmHg and pulmonary capillary wedge pressure (PCWP) ≤15 mmHg (after dialysis in group 1) and if other causes of PH were excluded. In CKD patients after dialysis, prevalence of PH was 24/31 (77%; 20/31 postcapillary PH, 4/31 precapillary PH); prevalence of PAH was 3/31 (10%). After dialysis, there were significant decreases in mPAP and PCWP; all four cases of precapillary PH were unmasked by dialysis. In group 2, postcapillary PH was diagnosed in 22 cases (71%); no cases of PAH were detected. Conclusions: The finding that the prevalence of PAH was 10% in CKD patients on hemodialysis who have unexplained dyspnea suggests careful screening for PH in this patient population is warranted. The possibility that dialysis might be a trigger for the development of PAH is plausible given that there were no instances of PAH in the nondialysis CKD patient group. RHC should be performed after dialysis to unmask precapillary PH.