Association of Volume Overload With Kidney Function Outcomes Among Patients With Acute Decompensated Heart Failure

Rationale & Objective

Reduced kidney function, as evaluated by estimated glomerular filtration rate (eGFR), is a powerful risk factor for adverse outcomes among patients with acute decompensated heart failure (ADHF). However, evidence that volume overload is a risk factor for declines in eGFR has been inconsistent. This study examined this association among adults with ADHF.

Study Design

Retrospective observational study.

Setting & Participants

Adult patients admitted to a quaternary referral hospital for a primary diagnosis of ADHF requiring right heart catheterization between 2015 and 2021.

Exposure

Initial central venous pressure (CVP), pulmonary capillary wedge pressure (PCWP), and change in CVP and PCWP.

Outcome

The eGFR when CVP and/or PCWP monitoring began, in-hospital eGFR slope, and initiation of dialysis through March 2022.

Analytical Approach

Restricted cubic splines and linear mixed models to examine the association of CVP and PCWP with baseline eGFR and in-hospital eGFR slope. Cox proportional hazard regression models were used to examine the association of CVP, PCWP, and changes in CVP and PCWP with initiation of dialysis. Sensitivity analyses were performed treating death as a competing risk.

Results

Among 753 patients, higher CVP and PCWP were significantly associated with lower eGFR (β, −5.01 [95% CI, −6.68 to −3.35] and −2.84 [95% CI, −4.55 to −1.13] mL/min/1.73m² per 1 SD higher CVP and PCWP, respectively) and lower in-hospital eGFR slope (β, −1.13 [95% CI, −1.57 to −0.69] and −0.59 [95% CI, −1.02 to −0.15] mL/min/1.73 m²/week per 1 SD higher). Over a median of 33 (IQR, 13-58) months, 62 patients (8.2%) required dialysis, and 264 patients (35.1%) died. Higher CVP and PCWP were associated with increased risk for dialysis: the adjusted HR per 1 SD higher CVP was 1.49 (95% CI, 1.17-1.90) and PCWP 1.30 (95% CI, 1.04-1.62). The associations remained consistent when treating death before dialysis as a competing risk. Change in CVP and PCWP were not associated with concomitantly assessed eGFR or risk of dialysis.

Limitations

Observational design.

Conclusions

Volume overload was associated with lower baseline kidney function, greater declines in eGFR, and increased risk of starting dialysis. Changes in the degree of volume overload were not associated with concomitantly assessed changes in eGFR or the risk of dialysis over follow-up.

Plain-Language Summary

Studies evaluating volume overload as a risk factor for kidney function decline have been inconsistent. This study included adult patients admitted to the hospital with acute heart failure (2015-2021) who required invasive monitoring of heart pressures. Statistical models analyzed how volume overload on both the right and left sides of the heart were associated with kidney outcomes, independent of other patient factors. Patients with greater volume overload had lower baseline kidney function, greater decline in kidney function during the hospitalization, and an increased risk of requiring dialysis over approximately 3 years of follow-up evaluation. However, changes in the degree of volume overload were not associated with changes in kidney function measured over the same period.