[Cardiorenal syndrome and its pathophysiological implications]

Cardiorenal syndrome is a pathophysiological condition in which combined cardiac and renal dysfunction amplifies individual organs failure progression. Therefore, morbidity and mortality is higher in this group patients. Its incidence has increased due to increased longevity and because patients survive more years with cardiac and/or renal dysfunction. The aim of the present paper is the revision of the most recent advances in this area. For a better comprehension and systematization of this syndrome it is suggested a classification in various subtypes (I-V). Type I reflects an abrupt worsening of cardiac function leading to acute kidney injury. Type II results from chronic abnormalities in cardiac function (chronic heart failure) causing progressive and potentially irreversible kidney disease. Type III consists of an abrupt worsening of renal function (acute kidney lesion) causing acute cardiac dysfunction (heart failure, arrhythmia or ischemia). Type IV describes a state of chronic kidney disease contributing to decrease cardiac function, ventricular hypertrophy, and/or increased risk of adverse cardiovascular events. Type V reflects a systemic condition causing both: cardiac and renal dysfunction. The clinical use of recently identified biomarkers can be an additional tool in the early diagnosis and stratification of this syndrome. This classification can be particularly useful in the identification of underlying abnormalities and in the establishment of an effective therapeutic approach.