Hemodynamic factors affecting pulmonary hypertension in hemodialysis patients

Abstract

Background:The fluid status and rate of blood flow through the arteriovenous fistula (AVF) are two important factors affecting hemodynamic in hemodialysis patients; however, their effects on pulmonary hypertension have rarely been studied. Hence, we aimed to evaluate the effects of these factors in hemodialysis patients with pulmonary hypertension. Methods: This single-center cross-sectional survey included 219 maintenance hemodialysis patients (139 [63.5%] male). The prevalence of pulmonary hypertension was 13.6% (30 of 219). Pulmonary artery pressure was measured by echocardiography, fluid status was measured objectively using bioimpedance spectroscopy, and blood flow rate in the AVF (Qa) was determined using Doppler ultrasound.Results: The overall mean overhydration before hemodialysis was 1.5 L (range, 0.6-2.8 L). The mean overhydration in patients with and without pulmonary hypertension was 3.6 L (range, 2.3-4.6 L) and 1.4 L (range, 0.6-2.4 L), respectively (p < 0.001). The overall mean Qa was 780 mL/min (range, 570-1,015.5 mL/min). The mean Qa of patients with and without pulmonary hypertension was 672 mL/min (range, 505.7-982.2 mL/min) and 790 mL/min (range, 591-1,026 mL/min), respectively (p = 0.27). Overhydration (odds ratio [OR], 1.46; 95% confidence interval [CI], 1.08-1.97; p = 0.01), N-terminal prohormone of brain natriuretic peptide (NT-proB-NP; OR, 1.36; 95% CI, 1.09-1.71; p = 0.007), and left atrial diameter (OR, 1.14; 95% CI, 1.01-1.28; p = 0.03) were risk factors. Conclusion: Pulmonary hypertension is strongly associated with overhydration, NT-proBNP, and left atrial diameter in hemodialysis patients.