Prevalence of and factors affecting pulmonary hypertension in hemodialysis patients.

Background: Pulmonary hypertension (PH) has been reported to be high among end-stage renal disease (ESRD) patients.

Objectives: The aim of this study was to investigate the role of arteriovenous fistula (AVF) flow in the pathogenesis of PH and the prevalence of PH in patients with chronic renal failure (CRF) and to suggest other possible etiologic factors.

Methods: The prevalence of PH was prospectively estimated by Doppler echocardiography in 116 ESRD patients on regular hemodialysis (HD). Laboratory and clinical variables were compared between patients with and without PH (groups 1 and 2, respectively). PH was defined as systolic pulmonary artery pressure (SPAP) over 30 mm Hg. Patients with PH underwent further evaluation by 2 pulmonologists. AVF flow was measured by Doppler ultrasonography. Blood tests including arterial blood gases, hemoglobin, serum calcium, phosphorus and parathyroid hormone were determined.

Results: PH was found in 25 (21.6%) patients (group 1) with an SPAP of 37.9 ± 2.8 mm Hg. Mean AVF flow was increased (1,554 ± 207.60 ml/min) in group 1. Left ventricular ejection fraction (LVEF) was significantly different between the 2 groups (55.3 ± 11.5 and 64.4 ± 40, respectively; p < 0.05). Neither significant primary lung disease nor parenchymal lesions were detected in group 1. PH showed a significant difference for cigarette smoking (p < 0.05). In group 1 the prevalence of cigarette smoking was higher. The main etiology of CRF was diabetes mellitus with a ratio of 44% in group 1.

Conclusion: Our study demonstrated a surprisingly high prevalence of PH among patients receiving long-term HD. PH was related to high AVF flow, low LVEF and cigarette smoking. AVF flow and cigarette smoking are important correctable causes of PH. Early detection is important in order to avoid the serious consequences.