Cardiorenal Syndrome Type 1 in Patients with Heart Failure with Preserved Ejection Fraction.

CRS type 1 (CRS-1) is defined as acute kidney injury (AKI) caused by acute decompensated heart failure (ADHF). HF is divided into three subtypes according to the value of ejection fraction (EF). HF with preserved ejection fraction (HFpEF) is an increasingly prevalent subtype of heart failure. A significant number of patients with HFpEF during episodes of acute decompensation (ADHFpEF) develop CRS-1. The objective of this narrative review is to summarize the data about the epidemiology, pathophysiological mechanisms, therapy, and prognostic impact of CRS-1 in patients with ADHFpEF. The most important pathophysiological mechanisms leading to the development of CRS-1 in these patients are hemodynamic disturbances and inflammation. Loop diuretics alone or in combination with other diuretics are the mainstay therapeutic option for treating congestion in patients with CRS-1. Introducing SGLT-2 inhibitors as soon as clinically possible has a positive impact on prognosis. CRS-1 is an independent predictor of a worse outcome in patients with ADHF, although this impact appears to be less associated in patients with HFpEF, than in patients with ADHF with reduced EF. Further studies are needed to better clarify pathophysiological mechanisms and develop treatments that improve cardiorenal outcomes in these patients.