Can Arterio-Venous Fistula (AVF) precipitate or worsen congestive heart failure in ESRD patients going for initiation of hemodialysis?

The chronic kidney disease patients are referred to vascular surgeons for creating an arterio-venous fistula for hemodialysis with different types of hidden cardio-vascular problems. We have noted that those patients with sub clinical congestive heart failure are at greater risk of worsening of the cardiac condition after creation of the arterio-venous fistula for hemodialysis. In general, it was observed that patients with CHF and ESRD have poor prognosis. Optimizing the hemodynamics is crucial in both these conditions. Adding the AVF as a third factor in these patients can also make the optimization of hemodynamics more difficult. When an AVF is created, it reduces peripheral resistance, increases the preload and the stroke volume and cardiac output are increased. In 7 to 10 days the cardiac output is increased by 15% to 20%, left ventricular end diastolic pressure is increased by 5% to 10%. The Atrial naturietic and brain naturietic factors (ANP, BNP) are elevated.  The higher flows throughs the AVF was not seem to be linked to the incidence of high output failure. The fistula flows will be twice higher in the upper limb than those at the wrist. The upper arm AVF flows (Q_a) will be between 1.13 to 1.72 Lit/min. The fistula flow can be higher than 2 lit/min (Q_a) in 15% of the patients. Generally, the ratio between cardiac output and fistula flow (Q_a) is 22% in the upper limbs. The risk of high output heart failure is high when CO/Q_a is more than 40%. It was observed that 17% of the patients developed de novo congestive heart failure in the HEMO study. Median time to develop high output heart failure will be 51 days and it is noted in 40% of the upper limb Brachio-cephalic and 8% of the Radio-cephalic arteriovenous fistula.

Dr. Pinjala R K

14 April 2017