Improvement of the left atrial systolic function after a surgical reduction of the high flow arteriovenous fistula.

Background: High-output heart failure (HOHF) is a distinct cardiac complication in end-stage kidney disease (ESKD) patients with high-flow arteriovenous fistulae (AVFs). While AVF flow reduction improves hemodynamics and left atrial (LA) volume, its effect on LA systolic function remains unclear. Objective: To evaluate changes in left atrial systolic function and left ventricular (LV) filling pressures following surgical AVF flow reduction in haemodialysis patients with high-flow fistulae. Methods: In this prospective, single-centre interventional study, 28 ESKD patients (mean age 63 ± 15 years) with high-flow AVFs (>1,500 mL/min) and clinical heart failure (NYHA ≥ II) underwent surgical AVF flow reduction. Echocardiographic assessments were performed before and 6 weeks after intervention. LA ejection fraction (LAEF) and LV filling pressures (E/e' ratio) were determined from digitally stored imaging data. Results: Surgical intervention reduced AVF flow by approximately 50% [2,525 [1,388] to 1,250 [700] mL/min, p = 0.00006]. LA volume index decreased significantly (44.7 ± 17.3 to 38.5 ± 15.4 mL/m2, p = 0.01), accompanied by an improvement in LAEF (49.6 ± 14.9% to 53.2 ± 13.5%, p = 0.046). Dyspnoea improved or resolved in all patients. Baseline LAEF correlated negatively with age, LA volume index, and NYHA class, but no independent predictors of post-operative LAEF improvement were identified. Conclusions: In patients with high-flow AVF-associated HOHF, surgical AVF flow reduction leads to a significant improvement in LA systolic function alongside decreased LA volume. These findings suggest partial reversibility of atrial remodeling induced by chronic hyperkinetic circulation and highlight the potential cardiovascular benefits of AVF flow optimization in selected dialysis patients.