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

Abstract

Rationale & objective: Reduced kidney function, as evaluated by estimated glomerular filtration rate (eGFR), is a powerful risk factor for adverse outcomes among patients with 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.

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

Outcomes: 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 treated death as a competing risk.

Results: Among 753 patients, higher CVP and PCWP were significantly associated with lower eGFR (β [95%CI]: -5.01 [-6.68, -3.35] and -2.84 [-4.55, -1.13] ml/min/1.73m² per 1 SD higher CVP and PCWP, respectively), and lower in-hospital eGFR slope (-1.13 [-1.57, -0.69] and -0.59 [-1.02, -0.15] ml/min/1.73 m²/week per 1 SD higher). Over a median of 33 (IQR 13, 58) months, 62 (8.2%) required dialysis and 264 (35.1%) died. Higher CVP and PCWP were associated with increased risk for dialysis: aHR (95%CI) per 1 SD higher CVP was 1.49 (1.17, 1.90) and PCWP 1.30 (1.04, 1.62). 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.