Cardiorenal syndrome: review of our current understanding

Abstract

Renal and cardiac diseases are both prevalent and carry significant morbidity and mortality. They share common vascular risk factors and are physiologically interlinked. Dysfunction in one organ affects the other. Concurrent renal and cardiac disease is associated with a poor prognosis. This close relationship is reflected through cardiorenal syndrome. A classification system has been proposed; however, the underlying process is complex and multifactorial. Management of this syndrome focuses on improving heart function, reducing volume overload, and managing heart failure and chronic kidney disease. This, however, is challenging, limited by paucity of evidence and may lead to suboptimal therapy. Increased recognition of this syndrome should raise awareness in providing early therapy and avoiding adverse outcomes due to under-treatment. In this article, we provide an overview of our current understanding of cardiorenal syndrome, as well as its pathophysiology and treatment options.

Mechanisms in fluid retention – towards a mutual concept

“…Cardiorenal syndrome type 1 and 2 cause fluid retention through mechanisms similar to the ones described under 'heart failure' main difference being the kidney injury contributing to further fluid retention (Jonsson et al, 2014;Hadjiphilippou & Kon, 2016).…”

An Update on the Pathophysiology and Treatment of Cardiorenal Syndrome

“…In order to oxygenate the kidney, the difference between the arterial driving pressure and venous outflow pressures must remain large enough to allow for adequate renal blood flow and glomerular filtration rate [1]. In HF, increased central venous pressure (CVP) leads to a reduction of both perfusion gradient across the glomerular capillary bed and renal function [4,5].…”

“…The mechanisms of progression are identified in Figure 3. Identifying this subtype is complex due to differing methods in defining AKI and determining the incidence of acute cardiac dysfunction [5]. It is difficult to establish causality of cardiac disease due to AKI given that multiple comorbid conditions can predispose to AKI.…”

“…CRS type 5 is characterized by the simultaneous presentation of cardiac and renal dysfunction as a result of an acute or chronic systemic condition and is illustrated in Figure 5. The most common condition that leads to CRS-5 is sepsis; others such as amyloid or vasculitis are less prevalent [5]. Compared to the other types of CRS, there is significantly less literature on CRS-5.…”

Three‐dimensional speckle‐tracking echocardiography for evaluating myocardial motion in patients with cardiorenal syndrome

“…The cardiovascular disease‐related mortality in dialysis patients is 10 to 30 times higher than that in the normal population. Septicemia is the most common systemic disease in CRS type 5 . AKI occurs in 11% to 64% of septic patients.…”