How to interpret serum creatinine increases during decongestion

Abstract

During decongestion in acute decompensated heart failure (ADHF), it is common to observe elevations in serum creatinine (sCr) values due to vascular congestion, a mechanism that involves increased central venous pressure that has a negative impact on the nephron, promoting greater absorption of water and sodium, increased interstitial pressure in an encapsulated organ developing "renal tamponade" which is one of main physiopathological mechanism associated with impaired kidney function. For the treatment of this syndrome, it is recommended to use diuretics that generate a high urinary output and natriuresis to decongest the venous system, during this process the sCr values can rise, a phenomenon that may bother some cardiologist and nephrologist, since raise the suspicion of kidney damage that could worsen the prognosis of these patients. It is recommended that increases of up to 0.5 mg/dL from baseline are acceptable, but some patients have higher increases, and we believe that an arbitrary number would be impractical for everyone. These increases in sCr may be related to changes in glomerular hemodynamics and true hypovolemia associated with decongestion, but it is unlikely that they are due to structural injury or truly hypoperfusion and may even have a positive connotation if accompanied by an effective decongestion and be associated with a better prognosis in the medium to long term with fewer major cardiovascular and renal events. In this review, we give a comprehensive point of view on the interpretation of creatinine elevation during decongestion in patients with ADHF.

Keywords: AKI; acute heart failure; cardiorenal syndrome 1; creatinine; decongestion.

FIGURE 1

Causes of increase in serum creatinine (sCr) during decongestion. Hypotheses that are unlikely to play a critical role, such as ischemic damage that induces acute tubular necrosis and sCr hemoconcentration, are described in the panel (left). In the panel (right), the theories that are more likely and would have more prominence during the appearance of this event such as renal hypoperfusion, the induction of true intravascular hypovolemia and neurohormonal activation with hemodynamic alteration of the afferent and efferent glomerular arteries. The image was licensed from Biorender.

FIGURE 2

Different trajectories of serum creatinine (sCr) during decongestion in cardiorenal syndrome 1. During effective decongestion in acute decompensated heart failure (ADHF), the increase in sCr < 0.5 mg/dL has been considered acceptable, and is associated with fewer major cardiorenal events, this arbitrary number seems to be inconsistent with reality, where even greater increases in sCr could be associated with the same benefit, but there could be patients whose values have negative connotations and reflect a worsening of kidney function that exceeds the benefit of decongestion. The image was licensed from Biorender.