Cardiorenal Syndrome in Heart Failure with Preserved Ejection Fraction: Insights into Pathophysiology and Recent Advances.

Background: Cardiorenal syndrome (CRS) refers to the bidirectional interactions between the acutely or chronically dysfunctioning heart and kidney that lead to poor outcomes. Due to the evolving literature on renal impairment and heart failure with preserved ejection fraction (HFpEF), this review aimed to highlight the pathophysiological pathways, diagnosis using imaging and biomarkers, and management of CRS in patients with HFpEF.

Summary: The mechanism of CRS in HFpEF can be hypothesized due to the interplay of elevated central venous pressure, renin-angiotensin-aldosterone system (RAAS) activation, oxidative stress, endothelial dysfunction, coronary microvascular dysfunction, and chronotropic incompetence. The correlation between HFpEF and worsening renal function seen in both long-term trials and observational data points to the evidence for these mechanisms. Upcoming biomarkers such as cystatin C, NGAL, NAG, KIM-1, ST-2, and galectin-3, along with conventional ones, are promising for early diagnosis, risk stratification, or response to therapy. Despite the lack of specific treatment for CRS in HFpEF, the management can be discussed with similar medications used in goal-directed medical therapy for heart failure with reduced ejection fraction (HFrEF). Additionally, there is increasing evidence for the role of vasodilators, inotropes, assist devices, and renal denervation, although long-term studies are necessary.

Key message: The management of CRS in HFpEF is an evolving field that currently shows promise for using diagnostic and prognostic biomarkers, conventional heart failure medications, and novel therapies such as renal denervation, interatrial shunt, and renal assist devices. Further studies are needed to understand the pathophysiological pathways, validate the use of novel biomarkers, especially for early diagnosis and prognostication, and institute new management strategies for CRS in patients with HFpEF.