Fluid loss, venous congestion, and worsening renal function in acute decompensated heart failure

To investigate the relationship between decongestion, central venous pressure, and risk of worsening renal function (WRF) in patients with acute decompensated heart failure (ADHF).

We studied 475 patients with ADHF, of whom 238 underwent right heart catheterization. Right atrial pressure (RAP) was measured at baseline and at 24 h. Net fluid loss was recorded in the first 24 h. WRF was defined as a >0.3 mg/dL increase in serum creatinine above baseline. WRF occurred in 84 catheterized patients (35.3%). There was a weak correlation between baseline RAP and baseline estimated glomerular filtration rate (r = -0.17, P = 0.009). The amount of fluid removed during the first 24 h did not correlate with the magnitude of RAP reduction (r = 0.06, P = 0.35). No association was observed between WRF and baseline RAP [odds ratio (OR) 1.06, 95% confidence interval (CI) 0.80-1.41, P = 0.68 per 6.6 mmHg] or the decrease in RAP (adjusted OR 1.13, 95% CI 0.85-1.49, P = 0.40 per 5.3 mmHg reduction in RAP). In contrast, smaller net fluid loss was strongly associated with increased WRF risk. Compared with the first net fluid loss tertile, the adjusted OR was 1.85 (95% CI 0.90-3.80, P = 0.10) and 2.58 (95% CI 1.27-5.25; P = 0.009) for the second and third tertile, respectively (P for trend <0.0001).

Smaller early net fluid loss is associated with increased risk for WRF. RAP is not a reliable surrogate of the magnitude of decongestion and risk of WRF. Future research is necessary to determine if targeting congestion may help prevent WRF.