Chronic Renocardiac Syndrome (Type 4 Cardiorenal Syndrome): A Comprehensive Review

Elmukhtar Habas¹, Ala Habas², Mohamed Bhagi³, Eshrak Habas⁴, Amnna Rayani⁵

Keywords: Cardiorenal syndrome, type 4 CRS, chronic kidney disease, heart failure, SGLT2 inhibitors, finerenone, mineralocorticoid receptor antagonist, cardiorenal protection, biomarkers

DOI: 10.63475/yjm.v5i1.0282

DOI URL: https://doi.org/10.63475/yjm.v5i1.0282

Publish Date: 05-04-2026

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Author Affiliation:

1 Professor of Internal Medicine, Qatar University, Hamad Medical Corporation, Hamad General Hospital, Doha, Qatar
2 Resident, Tripoli Central Hospital, University of Tripoli, Tripoli, Libya
3 Associate Consultant, Hamad Medical Corporation, Hamad General Hospital, Doha, Qatar
4 Resident, Tripoli University Hospital, University of Tripoli, Tripoli, Libya
5 Professor, University of Tripoli, Tripoli, Libya

Abstract

The five-subtype classification of cardiorenal syndrome (CRS), established a decade ago, provides a crucial framework for understanding the interdependent relationship between the heart and kidneys. Chronic renal cardiac syndrome (cRCS), categorized as type 4 CRS, is characterized by primary chronic kidney disease (CKD) that leads to persistent cardiac dysfunction, associated with markedly increased morbidity and mortality rates. The elevated risk is attributed to a multifaceted pathophysiological mechanism wherein advancing renal dysfunction induces metabolic anomalies, persistent inflammation, neurohormonal stimulation, and expedited vascular pathology, culminating in considerable structural harm to the heart. CKD has diverse cardiac effects, including systolic heart failure, diastolic dysfunction, arrhythmias, valvular calcification, and sudden cardiac death. Historically, management focused on support via volume control, dialytic optimization, and neurohormonal blockade. The therapeutic landscape for cRCS has undergone a notable paradigm shift. The use of sodium-glucose cotransporter-2 (SGLT2) inhibitors and non-steroidal mineralocorticoid receptor antagonists (MRAs) as critical, disease-modifying therapies offers a substantial opportunity to improve cardiovascular and renal outcomes. This review, current through December 2025, synthesizes contemporary epidemiology, pathophysiology, and evolving diagnostic approaches for cRCS, with an emphasis on evidencebased treatment strategies. An early and integrated cardiorenal management strategy is crucial for addressing the substantial and growing public health challenge posed by CKD.

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