Use of Angiotensin Receptor-Neprilysin Inhibitors (ARNis) in High-Output Heart Failure in a Young Hemodialysis Patient: Synergistic or Cumulative Effect?

In hemodialysis patients, an arteriovenous fistula (AVF) is the preferred option for vascular access. High-output heart failure (HOHF) due to a high-flow AVF can be an underrecognized complication, and arterial hypertension is among the most prevalent comorbidities in this population. Consequently, these patients are closely monitored during hemodialysis and routinely evaluated for cardiovascular pathology. A 32-year-old woman on hemodialysis for five years presented with hypertension refractory to triple pharmacologic therapy and dialysis, pleural effusion, exertional dyspnea, peripheral edema, and jugular venous distention. She was evaluated at an internal medicine day hospital to investigate the underlying cause of recurrent pleural effusion. She was found to have a concomitant high-flow AVF (Qa >3000 mL/min), which had undergone multiple banding procedures. Thoracentesis with cytobiochemical analysis revealed a transudative pleural effusion. Transthoracic echocardiography (TTE) demonstrated HF with reduced ejection fraction (38%) and pulmonary artery systolic pressure (PASP) of 46 mmHg; N-terminal pro-BNP (NT-proBNP) was 113,883 pg/mL. After multidisciplinary discussion, all antihypertensive therapy was replaced with intermediate-dose sacubitril/valsartan (SAC/VAL), aiming to control blood pressure and improve ejection fraction, with close monitoring of serum potassium and hemodynamics. Within two weeks, blood pressure control and symptoms improved significantly, with resolution of the pleural effusion. Two months after initiating SAC/VAL, the AVF was surgically closed, and dialysis access was switched to a long-term catheter. At six-month follow-up, repeat TTE showed recovery of ejection fraction to 71% and reduction of PASP to 23 mmHg. NT-proBNP decreased to 2,005 pg/mL, corroborating clinical improvement. The patient remains clinically stable. Continuous clinical assessment and individualized management are essential for addressing complex conditions in dialysis patients. Further research is warranted to establish the efficacy and safety of SAC/VAL in this population.