Cardiorenal syndrome caused by heart failure with preserved ejection fraction.

Since cardiorenal dysfunction is usually secondary to multiple factors acting in concert (and not only reduced cardiac output) in the present paper we are going to focus on the interrelationship between heart failure with normal ejection fraction and the development of cardiorenal syndrome. The coexistence of renal impairment in heart failure with preserved ejection fraction (CRS type 2 and 4) is common especially in older females with hypertension and/or diabetes. It can be hypothesized that the incidence of this disease association is growing, while clinical trials enrolling these patients are still lacking. The main mechanisms thought to be involved in the pathophysiology of this condition are represented by the increase of intra-abdominal and central venous pressure and the activation of the renin-angiotensin system. Differently from CRS in heart failure with reduced ejection fraction, the involvement of the kidney may be under-diagnosed in patients with heart failure and preserved ejection fraction and the optimal therapeutic strategy in this condition, though challenging, is far to be completely elucidated. Further studies are needed to assess the best therapeutic regimen in patients with renal dysfunction (and worsening) and heart failure and preserved ejection fraction.