The Intravenous Amino Acid Therapy for Vascular Rigidity in End Stage Renal Disease

The goal of this study is to learn if giving amino acids through the dialysis machine can help protect the blood vessels and heart in people with kidney failure. Patients on dialysis often have problems with stiff blood vessels, which increases their risk of heart attacks, strokes, and other cardiovascular diseases. A chemical change called carbamylation is thought to make blood vessels age and stiffen faster. Amino acids may block this process and improve blood vessel health. The main questions are: * Does amino acid treatment reduce the risk of death in dialysis patients? * Does it improve the health of the heart and blood vessels? * What side effects or medical problems happen when patients receive amino acids during dialysis? In this study: * Participants will be randomly assigned to receive either amino acids (Synthamin 9®) or a placebo (saline). * The infusion (250 ml) will be given twice a week during dialysis sessions for 12 months. * After 12 months of treatment, patients will be followed for another 6 months. During the study, patients will: * Have regular blood tests to measure markers of blood vessel health, inflammation, and protein carbamylation. * Undergo heart and vessel tests, including echocardiography, CT scans, and pulse wave velocity measurements. * Complete quality-of-life questionnaires about symptoms and daily living. By comparing the amino acid group with the placebo group, researchers will see whether amino acid therapy can make dialysis patients live longer and have healthier hearts and blood vessels.