RESULTS OF THE ANALYSIS OF THE EFFICACY AND SAFETY OF LONG-TERM ANTICOAGULANT THERAPY IN KAZAKH NATIONALITY PATIENTS AFTER OPEN HEART VALVE SURGERY

Background. Surgical replacement of heart valves with mechanical prostheses is a life-saving procedure for patients with valvular defects. Postoperative success depends heavily on the efficacy and safety of anticoagulant therapy. Warfarin remains the primary drug to prevent thrombotic complications in such patients. Despite its efficacy, warfarin requires individualized dosing, long-term monitoring, and careful bleeding risk assessment. It is a leading cause of serious adverse drug reactions, accounting for up to one-third of related hospitalizations and deaths. A pharmacogenetic approach is increasingly important in optimizing warfarin therapy. Gene polymorphisms affect warfarin metabolism and sensitivity, making the study of these factors particularly relevant in underrepresented populations, such as patients of Kazakh nationality. However, there is limited data on warfarin response in this group. Materials and Methods. This is the first study of its kind among Kazakh patients. It includes 310 individuals who underwent mechanical heart valve replacement and received warfarin therapy between 2015 and 2020. The aim was to evaluate the association between genotype, warfarin dose, and complication rates. Results. Patients showed variable coagulation responses, with INR fluctuations and both hemorrhagic and thrombotic complications documented. Risk factors for adverse outcomes were identified, underscoring the importance of individualized dosing and close monitoring. Conclusions. This study highlights the need for genotype-based dose adjustment to improve the safety and effectiveness of warfarin therapy in Kazakh patients after mechanical valve replacement.