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.

Background and Objective. Epistaxis is a frequent bleeding manifestation in patients receiving antithrombotic therapy, and its management falls between otolaryngology and cardiology guidance. We aimed to translate the evidence into an operational framework for joint decisions. Methods. PubMed/MEDLINE, Scopus, Embase, and the Cochrane Library were searched (January 2015 through August 2026), current ESC, ACC/AHA, EHRA, AAO-HNS, and SFORL guidance were analyzed, and national clinical protocols of different countries were screened; 67 sources were included. Results. Direct oral anticoagulants were consistently associated with fewer clinically relevant epistaxis events than warfarin, and minor epistaxis led to permanent anticoagulant discontinuation more often than minor bleeding at other sites. No guideline defines epistaxis severity, and guidance diverges on protected dual antiplatelet therapy, bleeding-risk assessment, and the sequence of local hemostasis and drug interruption. We propose a three-tier severity classification (minor, clinically relevant non-major, major) informed by ISTH and BARC definitions, a pragmatic thrombotic risk stratification, and an algorithm with agent-specific decisions. Conclusions. In minor and most clinically relevant non-major episodes, antithrombotic therapy can usually be continued while local hemostasis is achieved; interruption, de-escalation, or reversal should be individualized and reserved for uncontrolled or major bleeding. Effective local hemostasis can help avoid unnecessary interruption of antithrombotic therapy, and otolaryngologists should be part of multidisciplinary teams managing such bleeding.

Background. This study presents the results of a clinical trial evaluating the effectiveness of surgical treatments for atrial fibrillation in patients with rheumatic mitral valve disease. Special attention is given to the comparison of cryoablation and radiofrequency ablation, two methods used in conjunction with mitral valve surgeries. The results indicate that cryoablation, a method first used in Kazakhstan, has long-term advantages for restoring sinus rhythm and cardiac remodeling, thereby improving patients' quality of life. Materials and Methods. The study was conducted at the period from January 2020 to March 2024 through a retrospective analysis of data from patients with atrial fibrillation and rheumatic mitral valve disease who underwent surgical treatment using one of two methods: Cryoablation with left atrial appendage clipping (Group I) – 50 patients; Radiofrequency ablation with left atrial appendage suturing (Group II) – 50 patients. Results. According to the conducted research, both cryoablation and radiofrequency ablation are highly effective in restoring sinus rhythm in patients with atrial fibrillation and rheumatic mitral valve disease. Cryoablation, a procedure that was used for the first time in Kazakhstan, demonstrated significant advantages in the long-term maintenance of sinus rhythm and improvement in heart remodeling parameters, such as left atrial volume. This has enhanced the quality of life for patients. Conclusions. There is a need for the widespread implementation of innovative treatments for atrial fibrillation, such as cryoablation, as surgical procedures are more effective and patients with severe cardiovascular diseases have better outcomes.