Day-to-day experiences and challenges of long-term warfarin use among patients with prosthetic heart valves at a National Cardiac Institute in Tanzania: A qualitative study

Abstract

BACKGROUND: Long-term warfarin therapy following prosthetic heart valve placement is essential for preventing valve-related thromboembolic complications. Due to its narrow therapeutic window, maintaining a therapeutic International Normalized Ratio (INR) requires strict adherence to healthcare medication, dietary recommendations, and regular monitoring. Despite receiving education at discharge, patients with prosthetic heart valves continue to demonstrate poor adherence to warfarin therapy. While previous quantitative studies have identified factors associated with non-adherence, little is known about patients' day-to-day experiences and challenges with long-term warfarin use in low-resource settings. AIM OF THE STUDY: This study explored day-to-day experiences and challenges encountered during long-term warfarin use among patients with prosthetic heart valves attending a National Cardiac Institute in Dar es Salaam, Tanzania. MATERIALS AND METHODS: An explorative qualitative study design using inductive content analysis was conducted among twelve (12) patients with prosthetic valves on long-term warfarin therapy, who were purposively recruited based on the principle of data saturation between April 2025 and June 2025 at a national cardiac institute. In-depth interviews were conducted using a semi-structured interview guide. Data were analyzed manually using a deductive-inductive content analysis approach. RESULTS: Two main categories emerged from this study. The first category, adapting to life with long-term warfarin use, describes participants' experiences of symptom relief and improved quality of life after surgery, alongside issues related to dietary restrictions, medication side effects, emotional distress, and reduced engagement in socio-economic activities. Participants perceived dietary recommendations as restrictive and reported difficulties with lifestyle modifications required during long-term warfarin therapy. The second category, navigating warfarin care within an unstructured continuum of care, reports participants' struggles in maintaining therapeutic INR levels amid financial difficulties, inconsistent medication use, contradictory information from healthcare providers, and limited access to INR monitoring and warfarin services in peripheral regions. Some participants reported self-adjusting warfarin doses or missing follow-up appointments due to cost and accessibility barriers. CONCLUSION AND RECOMMENDATIONS: Although participants experienced clinical improvement post-surgery, they continued to face substantial challenges related to long-term warfarin use and access to anticoagulation care. Strengthening patient-centered education, improving continuity and consistency of anticoagulation counselling, decentralizing warfarin and INR monitoring services, and enhancing structured long-term follow-up systems may improve warfarin adherence and patient outcomes in low-resource settings.