Correlation of Albuminuria and Renal Doppler Indices with Myocardial Function in Patients with Nephrotic Syndrome

Background: Nephrotic syndrome (NS) is characterized by proteinuria and edema, often stemming from minimal change disease. Secondary causes include systemic conditions and medications. NS raises the cardiovascular risk due to inflammation, cytokine release, hypoalbuminemia, and impaired cardiac function. Renal Doppler ultrasound evaluates the renal microcirculation using resistive index (RI) and pulsatility index (PI). Objectives: To evaluate the impact of albuminuria and renal Doppler indices on myocardial function in patients with nephrotic syndrome, for early detection of myocardial dysfunction using speckle tracking echocardiography and renal Doppler imaging. Patients and methods: This cross-sectional study was carried out at Qena University Hospitals, involving 100 participants: 60 patients with nephrotic syndrome and hypoalbuminemia and 40 control cases. Clinical, laboratory, and imaging assessments, including echocardiography and renal Doppler, were performed. Left ventricular ejection fraction (LVEF), global longitudinal strain (GLS), E/e' ratio, resistive index (RI), and pulsatility index (PI) were measured. Results: The nephrotic group exhibited lower LVEF (63.3% versus 66.6%, p < 0.01) and GLS (-14.5 % versus -19.5 %, p < 0.001), along with an elevated E/e' ratio (7.15 versus 5.79, p < 0.01) compared to controls. Significant negative correlations were found between GLS and renal Doppler indices (RI and PI) (p < 0.001). Significant negative correlations were found between GLS and albumin creatinine ratio (ACR) (p = 0.0195). Conclusion: Albuminuria and impaired renal microcirculation negatively affect myocardial function in nephrotic syndrome. Early detection of myocardial dysfunction using echocardiography and renal Doppler is crucial for better cardiovascular risk management in these patients.