Anticoagulation Control and Associated Factors in Patients with Atrial Fibrillation Receiving Warfarin at a Tertiary Care Hospital in Nepal

Background Effective anticoagulation control is critical in patients with atrial fibrillation (AF) to prevent thromboembolic events. Warfarin remains widely used in resource-limited settings like Nepal, where maintaining therapeutic levels is often challenging. This study aimed to assess the proportion of anticoagulation control and identify associated factors in patients with AF receiving warfarin therapy. Methods A cross-sectional study was conducted among 235 AF patients receiving warfarin at a tertiary care hospital in Nepal. Anticoagulation control was evaluated using the Time in Therapeutic Range (TTR) calculated by the Rosendaal method. Sociodemographic, clinical, and medication-related data were collected and analyzed to identify factors associated with suboptimal TTR (<65%). Results The results showed that only 72 (30.6%) patients had a Time in Therapeutic Range of ≥ 65%. The mean percentage TTR is 40.14%. About 99 (42.1%) had International Normalized Ratio (INR) in the therapeutic range (2 - 3) on the hospital visit day. Statistical significance was found between good anticoagulation control and female gender. Similarly, good anticoagulation control was observed in the patients who never consumed Vitamin K-containing foods and among the patients with more than 5 years of therapy. Conclusion This study demonstrated that a significant proportion of individuals receiving warfarin therapy for atrial fibrillation in Nepal had suboptimal anticoagulation control. The relatively high prevalence of out-of-range INR values warrants further investigation to identify underlying causes and contributing factors. The study emphasizes the important role of clinical pharmacists in improving warfarin management and recommends regular, structured monitoring of PT-INR levels to enhance treatment effectiveness and reduce the risk of complications .