# Kidney Outcomes in Patients With Advanced Heart Failure Treated With Ventricular Assist Devices

## TL;DR

Ventricular assist devices initially improve kidney function in heart failure patients, especially those with chronic kidney disease, but benefits fade over time.

## Contribution

This study provides new insights into the longitudinal effects of VADs on kidney function in patients with and without chronic kidney disease.

## Key findings

- Kidney function improved in CKD patients 3 months post-VAD but declined by 12 months.
- AKI requiring KRT occurred in 14% of patients, with 45% in-hospital mortality.
- Heart transplant was associated with worsening kidney function at 1 year.

## Abstract

Ventricular assist devices (VADs) are used for advanced heart failure, but their impact on kidney function remains unclear. This study evaluated changes in kidney function following VAD implantation, including acute kidney injury (AKI) incidence and need for kidney replacement therapy (KRT).

A retrospective cohort study analyzing longitudinal kidney function outcomes post-VAD placement.

Adult patients who underwent durable VAD placement (2009-2019) at a single center were included. Patients were stratified into chronic kidney disease (CKD) (estimated glomerular filtration rate [eGFR] <60 mL/min/1.73m2) and non-CKD (eGFR ≥60 mL/min/1.73m2) groups.

The VAD implantation was the primary intervention, with baseline kidney function modifying its impact on post-VAD kidney function.

Primary outcomes were changes in eGFR and creatinine at 3-months and 12-months post-VAD. Secondary outcomes included AKI incidence, KRT requirement, and postdischarge AKI within 1 year.

Descriptive statistics and comparative analyses, including Wilcoxon rank sum, χ2, and paired t tests, were used to assess differences. Significance was set at P < 0.05.

Among 160 patients (82% male and 69% White), patients with CKD were older with a higher prevalence of diabetes, vasodilator use, and inotrope use. At 3 months, kidney function improved in patients with CKD (eGFR +17, P < 0.001) but declined by 12 months (eGFR +7, P = 0.03). The non-CKD group had a smaller improvement at 3 months (eGFR +8, P = 0.004) that was not sustained. AKI requiring KRT occurred in 14%, with 45% in-hospital mortality; and 41% discontinued KRT before discharge. Post-VAD AKI occurred in 21%. Half of the patients underwent heart transplant, which was associated with worsening kidney function at 1-year.

Single-center design limits generalizability.

The VAD placement initially improves kidney function, particularly in CKD patients, but this effect diminishes over time. AKI and KRT use are common, highlighting the need for close kidney monitoring post-VAD.

Ventricular assist devices (VADs) help patients with advanced heart failure by supporting heart function, but their impact on kidney health is not well understood. Because kidney disease is common in heart failure and linked to worse outcomes, we studied how kidney function changes after VAD placement. We compared patients with and without chronic kidney disease and found that kidney function improved in the first 3 months, especially in those with chronic kidney disease. However, this benefit declined over the first year. Some patients developed acute kidney injury requiring dialysis, which significantly increased their risk of death. These findings highlight the importance of closely monitoring kidney health in VAD patients to improve long-term outcomes.