Pulmonary hypertension in end-stage renal disease patients on dialysis and predialysis patients

Purpose: Pulmonary hypertension (PH) is a frequent and serious cardiovascular complication in patients with end-stage renal disease (ESRD) on dialysis. The purpose of this study was to investigate the prevalence of PH and its associated factors in patients with ESRD on maintenance dialysis and predialysis patients. Methods: The medical records of ESRD patients who underwent kidney transplantation between January 2011 and December 2017 were retrospectively reviewed. Demographic and clinical characteristics including echocardiographic findings before joining the waiting list for transplantation were evaluated and compared among groups divided according to dialysis or not and dialysis types. The results of transthoracic Doppler echocardiography were used to determine the pulmonary artery pressure. Pulmonary hypertension was defined as a systolic pulmonary artery pressure (sPAP) greater than 35 mmHg. Univariate and multivariate analyses were used to investigate factors associated with PH. Results: Data from 35 pre-dialysis patients with ESRD, 72 maintenance hemodialysis (HD) and 34 peritoneal dialysis (PD) patients were analysed. Pulmonary hypertension was 20.69% in pre-dialysis patients, 16.7% in HD patients and 14.7% in PD patients (P=0.957). There were negative correlations between sPAP and calcium (r=-0.230, P=0.012), Ca×P(r=-0.210, P=0.021), hemoglobin (r=-0.243, P=0.008) and a positive correlation between sPAP and cardiac output (r=0.481, P=0.000). Cardiac output (CO) was an independent risk factor of sPAP (B=1.431, confidence interval [CI] 95%: 0.687 to 2.175, P=0.000). Conclusion: Incidence of PH was not statistically different in ESRD patients on dialysis and pre-dialysis patients. Uremia may play a major role in the pathogenesis of PH in patients