TỶ LỆ ĐẠT INR MỤC TIÊU VÀ KIẾN THỨC THỰC HÀNH ĐÚNG Ở BỆNH NHÂN DÙNG THUỐC KHÁNG VITAMIN K SAU PHẪU THUẬT VAN TIM

Abstract

Background: Lifelong anticoagulation with vitamin K antagonists (VKAs) is essential for preventing thromboembolic complications in patients after mechanical heart valve replacement by maintaining the international normalized ratio (INR) within the therapeutic range. However, the effectiveness of anticoagulation therapy is influenced by several factors, including diet, drug interactions, and most notably, patients’ adherence and knowledge regarding VKA use. Objective: To assess the proportion of patients achieving target INR values and to evaluate the level of practical knowledge regarding VKA therapy in patients after cardiac valve surgery. Methods: A cross-sectional descriptive and analytical study was conducted on 294 patients who had undergone mechanical heart valve replacement at Thong Nhat Hospital between January and December 2022. Data collected included demographic characteristics, valve type, weekly VKA dosage, INR values, bleeding complications, and patients’ knowledge about anticoagulation therapy. Results: Of the 294 patients included, 44.22% were male (130/294), with a mean age of 55.3 ± 10.2 years. Mitral valve replacement was the most common type (53.06%, 156/294). The average weekly dose of warfarin was 28.34 ± 9.34 mg, while for acenocoumarol it was 13.71 ± 3.1 mg. A total of 72.11% (212/294) of patients achieved target INR levels, and the incidence of bleeding complications was 17.3%. Only 23.13% (68/294) of patients demonstrated good knowledge of anticoagulant use. A positive correlation was observed between patients' knowledge and the effectiveness of anticoagulation therapy. Conclusion: This study highlights that patients’ knowledge regarding VKA therapy remains limited, which may impact the likelihood of maintaining INR within the therapeutic range in this population.