Kidney Replacement Therapy in Cardiorenal Syndromes

Cardiorenal syndromes (CRS) have increasingly been recognized as distinct disorders that affect the heart and kidneys simultaneously, either with acute or chronic onset. The different types share common pathophysiological characteristics. The concept "cardiorenal" shall emphasize the inter- or even multidisciplinary approach to respective patients. Anticongestive therapy becomes mandatory in many subjects that suffer from CRS. In recent years, the role of dialysis treatment in a broader sense has been investigated in CRS in more detail. We performed a search for studies related to the topic in the following databases: MEDLINE, PROSPERO, and Web of Science. The following keywords were used for reference identification: "CRS", "cardiorenal syndrome", "dialysis", "hemodialysis", "hemofiltration", "renal replacement therapy", "kidney replacement therapy", "peritoneal dialysis", and "aquapheresis". Finally, a total number of 22 studies, partly performed as retrospective cohort studies, and partly designed as prospective investigations, were included. The selected studies evaluated different modes of peritoneal dialysis (PD) or of non-PD procedures including intermittent hemodialysis, continuous procedures, and so-called aquapheresis. Inclusion and outcome parameters were almost not comparable between selected trials. Some studies revealed dialysis as effective, with reasonable tolerability. Particularly so-called "pure" ultrafiltration (e.g., aquapheresis) was associated with higher rates of adverse events. Future studies should be designed in a more homogenous manner, particularly concerning the inclusion criteria, the respective dialysis procedure applied, and endpoints in the short- and long-term.