Decongestion, kidney injury and prognosis in patients with acute heart failure

In patients with acute heart failure (AHF), the development of worsening renal function with appropriate decongestion is thought to be a benign functional change and not associated with poor prognosis. We investigated whether the benefit of decongestion outweighs the risk of concurrent kidney tubular damage and leads to better outcomes.

We retrospectively analyzed data from the AKINESIS study, which enrolled AHF patients requiring intravenous diuretic therapy. Urine neutrophil gelatinase-associated lipocalin (uNGAL) and B-type natriuretic peptide (BNP) were serially measured during the hospitalization. Decongestion was defined as ≥30% BNP decrease at discharge compared to admission. Univariable and multivariable Cox models were assessed for one-year mortality.

Among 736 patients, 53% had ≥30% BNP decrease at discharge. Levels of uNGAL and BNP at each collection time point had positive but weak correlations (r ≤ 0.133). Patients without decongestion and with higher discharge uNGAL values had worse one-year mortality, while those with decongestion had better outcomes regardless of uNGAL values (p for interaction 0.018). This interaction was also significant when the change in BNP was analyzed as a continuous variable (p < 0.001). Although higher peak and discharge uNGAL were associated with mortality in univariable analysis, only ≥30% BNP decrease was a significant predictor after multivariable adjustment.

Among AHF patients treated with diuretic therapy, decongestion was generally not associated with kidney tubular damage assessed by uNGAL. Kidney tubular damage with adequate decongestion does not impact outcomes; however, kidney injury without adequate decongestion is associated with a worse prognosis.