The Kidney Cardiac Link

The Kidney Cardiac Link

interaction between chronic kidney disease (CKD) and cardiovascular disease (CVD), termed the cardiorenal syndrome (CRS), is characterized by enhanced risk of atherosclerosis and uremia-related myocardial disorders (Figure 1). While milder degrees of renal impairment (CKD stages 1–3) are associated with accelerated risk of atherosclerotic events, a uremia-specific cardiomyopathy characterizes the more severe and advanced stages of renal dysfunction and end stage renal disease (ESRD) (stages 4, 5, and ESRD) (Figure 1).

Figure 1. Guanylyl cyclase (GC) pathways, activation of cGMP as their second messenger

anemia is common in congestive heart failure (CHF) and is associated with increased mortality, morbidity, and progressive renal failure. The two most common causes of the anemia are associated renal failure, which causes depression of erythropoietin production in the kidney, and excessive cytokine production, which can also cause depression of erythropoietin production in the kidney as well as depression of the erythropoietic response in bone marrow.

renal dysfunction is a common and often progressive complication of heart failure (Figure 1). Renal function is—to use a descriptive term—“twitchy” in the patient with heart failure. It can change relating to patient volume status, concomitant medications, and adequacy of pump function, with all factors influenced by the background level of renal function.

most cardiologists consider the coexistence of heart failure and chronic kidney disease (CKD) (1) or worsening of renal function (WRF) defined as an increase in serum creatinine >0.3 mg/dL (2) during treatment of acute decompensated heart failure (ADHF) as a reasonable working definition of cardiorenal syndrome (CRS).

the interaction between the heart and the kidney is well known. Congestive cardiac failure can be tied to acute renal failure with prerenal origin or, if it is sustained in time, to renal failure. Chronic cardiac disease and chronic kidney disease can both lead to chronic disturbances in the other organ. Lindner et al. published work describing the association between hemodialysis and accelerated atherosclerosis (1).

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Cardiac and renal diseases are common and frequently coexist, adding to the complexity and costs of care, and ultimately, to increased morbidity and mortality (1).

Cardiorenal syndrome can be defined as a pathophysiological state in which primary dysfunction of one organ (the heart or the kidney) induces or exacerbates dysfunction of the other. Cardiorenal syndrome occurs through multiple mechanisms that demonstrate the complex interaction between the two organs.