Surgical reduction of a high-flow dialysis fistula has long-term positive effects of the heart

Abstract Introduction Part of chronic haemodialysis patients develop a high-flow arteriovenous fistula (AVF). The volume overload caused by the presence of a high-flow AVF leads to increased cardiac output, dilation of cardiac chambers, increased pulmonary artery pressure or even to the development of high-output heart failure. Our previous data showed a positive effect of AVF flow-reducing surgery in 6 weeks follow-up. Purpose The purpose of this study was to analyse the long-term effect of AVF blood flow (Qa) reduction on cardiac structure and function. Methods We included patients with high-flow AVFs (defined as Qa over 1500 mL/min) indicated for blood flow reduction surgery for heart failure symptoms or pre-defined echocardiographic changes (left ventricular hypertrophy, severe secondary valvular regurgitations, or pulmonary hypertension). Echocardiography was performed one day before the surgery, the 6 weeks, 6 months, and 12 months thereafter. Qa was measured by ultrasound during the same visits. Results 27 patients were included, 20 men and 7 women, aged 57 ± 13 years. The procedure led to an immediate decrease in Qa. However, we observed failure of the procedure within 1 year in 8 (= 30%) patients defined by increased Qa back to pre-surgery values. Detailed results are displayed in Table 1. Estimated pulmonary arterial systolic pressure and left atrial volume remained significantly lower after 1 year despite the Qa rise. Effective cardiac output (= difference of cardiac output and Qa) rose immediately and remained increased during the follow-up period despite the increase in AVF blood flow. Conclusions We observed a long-time positive effect of AVF blood flow reduction surgery on the heart despite a significant Qa rise. The effective cardiac output remained increased despite the gradual increase of Qa, probably due to the adaptation of systemic arterioles.