Pulmonary Hypertension in the Setting of Hemodialysis Arteriovenous Fistulas: Natural History and Outcomes

Abstract

<h3>Purpose</h3> Patients with arteriovenous fistulas (AVF), whether used for hemodialysis or abandoned prior to or after use, are at increased risk for development of pulmonary hypertension (PH). The purpose of this study is to describe the demographic and clinical characteristics of patients with both arteriovenous fistulas and pulmonary hypertension to better understand this subset of patients. <h3>Methods</h3> All patients ≥18 years old, with echocardiography, AVF placement and/or revision, and right heart catheterization (RHC) procedures seen at the Minneapolis Heart Institute (MHI) between 1/1/2010 and 3/31/2020. Fistula placement must have preceded RHC in order to capture any interactions between the AVF and PH. Patients were grouped by class of PH using standard definitions. <h3>Results</h3> Of 39 patients, one had group 1 PH (pulmonary arterial hypertension, PAH), eight had group 1* PH (combined pre-and post-capillary pulmonary hypertension, CPC-PH), 24 had group 2 PH, two patients had group 3 PH, and four had group 5 PH due to high cardiac output. Hypertension, diabetes, obstructive sleep apnea, and coronary artery disease were the most common comorbidities present. 58% of patients had moderate/severe left atrial enlargement, 49% had moderate/severe right atrial enlargement, and 29% had moderate/severe right ventricular enlargement and dysfunction. Only six patients had a cardiac output greater than 8 L/min, suggesting that high output caused by the fistula was not the primary contributor to most patients' PH. Two-year survival for patients was 56%. <h3>Conclusion</h3> Group 2 PH is predominant among individuals with end-stage renal disease and AVF, suggesting that PH in this population is usually not caused by high flow through AVF, but rather due to comorbidities and other factors. Additionally, low survival estimates suggest that PH is a poor prognostic indicator for patients with ESRD.