Beyond Creatinine: Novel Renal Biomarkers at the Interface of Kidney Injury and Cardiovascular Risk

Chronic kidney disease, acute kidney injury and cardiorenal syndrome are major determinants of cardiovascular morbidity and mortality, yet conventional renal assessment based on serum creatinine, estimated glomerular filtration rate and urine output often fails to detect early structural injury or pathway-specific cardiorenal risk. This narrative review synthesized recent evidence on emerging renal and cardiorenal biomarkers with potential value for cardiovascular risk stratification beyond creatinine. Literature published between 2015 and April 2026 was reviewed, focusing on biomarkers of tubular injury, functional renal impairment, fibrosis/remodeling and mineral metabolism. NGAL and KIM-1 may detect tubular stress and proximal tubular injury before overt functional decline and have shown relevance in heart failure, acute coronary syndromes and post-cardiac surgery settings. Cystatin C and pro-enkephalin refine functional renal assessment and may improve prognostic classification when creatinine is confounded by frailty, muscle mass or acute hemodynamic changes. Soluble ST2 and galectin-3 reflect inflammation, fibrosis and cardiorenal remodeling, while FGF-23 links kidney dysfunction to cardiovascular risk through phosphate imbalance, vascular calcification and myocardial hypertrophy. Multi-biomarker panels may help identify dominant cardiorenal phenotypes and personalize monitoring intensity. However, routine implementation requires standardized assays, validated thresholds, cost-effectiveness data and prospective evidence that biomarker-guided management improves clinical outcomes.