The clinical challenge of cardiorenal syndrome.

Renal dysfunction is a common and progressive complication of chronic heart failure, with a clinical course that typically fluctuates with the patient’s clinical status and treatment. Despite growing recognition of the frequent presentation of combined cardiac and renal dysfunction, or “cardiorenal syndrome,” its underlying pathophysiology is not well understood, and no consensus as to its appropriate management has been achieved. Because patients with heart failure are surviving longer and dying less frequently from primary arrhythmia, we expect that the cardiorenal syndrome will become more common. Against this background, the article by Wang and colleagues1 in the present issue of Circulation is particularly significant because it is the first prospective, controlled therapeutic trial in patients with this condition. To place the findings and implications of this study in context, we first briefly review what is currently known about the cardiorenal syndrome and its treatment options.