Worsening Renal Function during Decompensated Heart Failure: The Cardio-abdomino-renal syndrome

Abstract

The syndrome of heart failure is characterized by complex hemodynamic alterations with the hallmark being elevated filling pressures leading to symptoms of congestion. The pathophysiology of the interactions between heart and kidney is still insufficiently elucidated and in the setting of acute decompensated heart failure, coexisting renal insufficiency often complicates the treatment course. Historically, poor forward flow, i.e., low cardiac output, has been considered the culprit mechanism of acute decompensated heart failure, but growing evidence has emphasized the importance of venous congestion, not only for the progression of heart failure, but also for the development of worsening renal function during its treatment course. A potential role of the abdomen, through coexisting elevated intra-abdominal pressure (IAP), has recently been proposed. Therefore, the traditional perception of worsening renal function secondary to hypoperfusion of the kidneys through low-flow states has been challenged by the actual hemodynamics present, characterized by congestion and elevated IAP, leading to the concept of ‘congestive kidney failure’ or ‘cardio-abdomino-renal syndrome’. This review will discuss the contemporary pathophysiological insights into the role of systemic venous congestion and elevated IAP in acute decompensated heart failure and its repercussions on the heart, kidneys and abdominal compartment. Current and future treatment strategies, aiming to relieve congestion while preserving renal function, will also be discussed.