Comparative Assessment of Glomerular Filtration Rate Using Cystatin C and Creatinine in Early Cardiorenal Syndrome

Abstract

Cardiorenal syndrome is characterized by the coexistence of cardiac and renal dysfunction, significantly worsening patient prognosis. Early detection of renal impairment remains challenging, as creatinine-based estimation of glomerular filtration rate (GFR) lacks sensitivity in early stages. Cystatin C has emerged as a promising biomarker for more accurate assessment of kidney function. Methods: This cross-sectional study included 115 patients with chronic heart failure (New York Heart Association [NYHA] class II–III) complicated by early-stage cardiorenal syndrome. Patients were divided into NYHA II (n=30) and NYHA III (n=85) groups. Serum creatinine and cystatin C levels were measured, and GFR was calculated using CKD-EPI equations. Statistical analysis was performed using Student’s t-test, with p<0.05 considered significant. Results: In NYHA II patients, creatinine-based GFR was 88.4±1.57 ml/min/1.73 m², while cystatin C-based GFR was significantly lower at 61.3±3.6 ml/min/1.73 m² (p<0.001). In NYHA III patients, the corresponding values were 79.3±1.67 and 53.5±1.06 ml/min/1.73 m², respectively (p<0.001). Cystatin C-based GFR was consistently lower than creatinine-based estimates in both groups, indicating earlier detection of renal dysfunction. Additionally, GFR values decreased with increasing NYHA functional class. Conclusion: Cystatin C-based estimation of GFR provides a more sensitive assessment of early renal dysfunction in patients with cardiorenal syndrome compared to creatinine-based methods. Its use may improve early diagnosis and clinical management of these patients.