Introduction: The problem of cardiorenal syndrome (CRS) in patients with acute coronary syndrome (ACS) and arterial hypertension (AH) is highly relevant. Early diagnosis, based on cystatin C, microalbuminuria, and arterial stiffness, is key for prognosis and therapy selection. Aim: To assess CRS marker dynamics and arterial stiffness in patients with ACS, AH, and chronic kidney disease (CKD) on standardized therapy, and to develop a treatment selection algorithm. Materials and Methods: A prospec