Analysis of results to optimize anticoagulant therapy in patients who underwent mechanical heart valve replacement: a pilot singlecenter controlled study

Aim. This study aims to conduct a comparative analysis of anticoagulant-related complications and clinical outcomes in patients with mechanical aortic valve prostheses who are on long-term warfarin therapy. The analysis will focus on two groups: those maintained at therapeutic INR values (3 ± 0.5) and those maintained at reduced INR values (2 ± 0.5). Material and methods. The analysis of a prospective, randomized, single-center study included 80 patients (56% men and 44% women) who underwent mechanical aortic valve replacement between March 2020 and September 2022. The observation period lasted 12 months, with an average age of 59 years (range: 50-63). The primary endpoint was a composite outcome measured over 12 months, consisting of death, symptomatic bleeding, thrombosis, and thromboembolism. Patients were enrolled based on the following inclusion criteria: mechanical prosthesis in the aortic position implanted more than three months prior, age over 18 at the time of inclusion, and provision of written informed consent. Exclusion criteria included multivalvular prosthetics, history of cardiac cavity thrombosis, left ventricular ejection fraction of less than 30%, atrial fibrillation/flutter, pregnancy or plans for pregnancy during the study, patient refusal at any stage of the study, liver pathology (types B and C according to Child- Pugh), and severe renal failure (creatinine clearance <30 ml/ min). Results. All participants (n = 80, 100%) completed the pilot study. Among the 40 patients in the study group, 6 (7.5%) experienced events related to the primary endpoint. The odds ratio for the primary endpoint at 12 months was 2.71 (p = 0.25). Additionally, the odds ratio for the primary endpoint at 18 months was calculated to be 3.35 (p = 0.155). Given the observed negative trend in the frequency of disabling events in the primary group, and despite the lack of statistically significant differences, the study was terminated at the pilot stage for ethical reasons. Conclusion. This study reveals a negative trend in the frequency of primary endpoint events among patients with reduced INR levels. Notably, the majority of these events consisted of ischemic strokes, which occurred in 5% of the study group. Consequently, the optimal target INR range for patients who have undergone heart valve replacement with mechanical prostheses remains inadequately defined