Effectiveness Study On longitudinal Laboratory monitoring Of the INR in Patients Receiving Vitamin-K Antagonist For Atrial Fibrilation in R.Macedonia

Atrial fibrillation is preventable cause for ischemic stroke and various other thrombo-embolic events. One of the main agents used in the prevention of the consequences are the vitamin-K antagonists. Although efficacy is proven, studies have questioned their efficiency in this setting. Various factors contribute to variations of their efficiency, which is still underinvestigated in many health systems. Few studies have shown varied estimates and cited different reasons for its effectiveness, ranging from subtle differences in diet, concurrent medications use, variable level of enzyme activity to age and compliance of users, which can vary unexpectedly. The aim of the present study of effectiveness is to describe how often patients that use VKA achieve the targeted values for INR. The population consists of the hospital reach area of Clinical Hospital Tetovo, observed for 6 months with routine laboratory investigation for the values of INR. Our study reveals that 57.4% of all measurements of INR where within the target values between 2-3, while 9.7% of all measurements revealed extreme values that can put patients at risk for further thrombo-embolic events or catastrophic hemorrhagic events

Effectiveness of Vitamin K antagonist for secondary prophylaxis of brain stroke in patients with atrial fibrillation in routine public care settings

Vitamin K antagonists are the mainstay for prevention of strokes in patients with atrial fibrillation (AF) world-wide. Yet estimates on its effectiveness are heterogeneous and reveal stark differences between different health-care systems. The aim of the present study was to assess the laboratory parameters for achieving the goal of the therapy (Time in therapeutic range – TTR) and to describe the effectiveness of the therapy in real-time setting. Methods : Patients treated in our clinic, with confirmed AF were considered in the study. The study was prospective observational study by design, where the participants were assessed at baseline for known risk factors for stroke, diagnosis for atrial fibrillation, use of anticoagulant medication and presence of identifiable ischemic lesions in the brain with non-contrast computed tomography (NCCT). The drug of choice was acenocoumarol, with planned monthly measurements of INR with the duration of 6 months, and the study was concluded with additional NCCT at the end, in order to assess for differences. Results : 96 patients finished the observation. The mean age of the patients was 64.5 years (SD = 6.36), and 50 (52%) were male. Regarding the INR measurement, we collected data from 88.2% of the planed measurements; 69.7% of the patients achieved TTR above 60%. Cross-comparison between groups (TTR 60%) revealed that the first group had statistically significant higher proportion of patients with newly registered lesions on NCCT (p-value < 0.05). Conclusion: Acenocoumarol is the only therapeutic VKA option in our country, despite the availability of other VKA antagonists that show better indices for effectiveness. Our sample confirmed that the proper use of VKA significantly reduces the incidence of new NCCT ischemic lesions in conditions of routine public health care