Valvular heart disease remains a major cause of morbidity globally and is commonly treated with valve replacement surgery in severe cases. Patients with prosthetic heart valves require lifelong anticoagulation to prevent valve-related thromboembolic events. Warfarin remains the standard anticoagulant for mechanical valves because direct oral anticoagulants have limited evidence and accessibility in this population and setting. Effective anticoagulation requires adherence to medication, dietary and lifestyle recommendations, and regular monitoring of the INR to maintain the target therapeutic range specific to valve type.
Suboptimal anticoagulation control among warfarin users has been widely reported in sub-Saharan Africa. Quantitative studies have identified correlates of poor adherence, but they provide limited insight into how patients experience and manage long-term anticoagulation in daily life, particularly in low-resource settings such as Tanzania. This study sought to fill that gap by exploring lived experiences and system-related barriers that affect warfarin use after prosthetic valve surgery.
The study aimed to explore day-to-day experiences and challenges encountered by patients with prosthetic heart valves regarding long-term warfarin use at a National Cardiac Institute in Dar es Salaam, Tanzania.
An exploratory descriptive qualitative design was used to gather detailed accounts of patients’ everyday management of long-term warfarin therapy after hospital discharge. The study employed qualitative content analysis to preserve context while systematically describing and interpreting participant narratives. Data collection occurred at a national cardiac referral centre in Dar es Salaam between April and June 2025.
Twelve patients with prosthetic valves on long-term warfarin therapy were purposively recruited according to the principle of data saturation. In-depth interviews were conducted using a semi-structured interview guide. Participants had received discharge education about consistent medication use, dietary and lifestyle modifications, and INR monitoring prior to leaving the hospital.
Interview transcripts were analyzed manually using a combined inductive–deductive content analysis approach. The analytic process allowed identification of themes describing both individual adaptation to lifelong anticoagulation and interactions with the health system that influenced adherence and monitoring.
Participants commonly reported clinical improvement and symptom relief following valve surgery, with perceived enhancement in quality of life. Despite these gains, daily life with long-term warfarin involved multiple challenges. Participants described strict dietary recommendations as restrictive and difficult to sustain. Medication side effects were noted and contributed to emotional distress for some patients.
Several participants described reduced engagement in socio-economic activities because of fears about bleeding, scheduling of follow-up visits, or side effects. Emotional burden and ongoing worry about the risks of thrombosis or bleeding were recurrent themes. Although patients had received education at discharge, many still found it difficult to negotiate dietary and lifestyle changes in the context of their households and communities.
The second major theme highlighted system-level barriers that made maintaining therapeutic INR challenging. Financial difficulties were repeatedly cited as a barrier to consistent medication purchase, travel to the referral centre, and access to INR testing. Limited availability of INR monitoring and warfarin services in peripheral regions forced patients to travel to the national centre or to forgo monitoring.
Participants also reported inconsistent medication use driven by cost or supply issues. Contradictory information from different healthcare providers undermined confidence in dosing and follow-up plans. In some cases, patients described self-adjusting warfarin doses or missing follow-up appointments because of cost and accessibility barriers. These behaviors increased the risk that INR would fall outside the therapeutic range, with attendant bleeding or thrombotic risks.
Although patients in this study experienced clinical improvement after valve replacement, long-term warfarin use remained burdened by both personal and health system challenges. Key issues included restrictive dietary guidance, medication side effects, emotional distress, financial barriers, limited decentralization of INR services, inconsistent messaging from providers, and gaps in structured long-term follow-up.
The authors recommend strengthening patient-centered education, improving continuity and consistency of anticoagulation counselling across providers, decentralizing warfarin dispensing and INR monitoring services to peripheral facilities, and implementing structured systems for long-term follow-up. These measures were proposed to improve adherence and anticoagulation outcomes in low-resource settings.
The study was funded by Muhimbili University of Health and Allied Sciences (MUHAS) through institutional research support awarded to the lead author. Co-authors affiliated with MUHAS contributed in academic and supervisory roles and did not receive specific funding for the work. Important supporting materials, including the interview guide, COREQ checklist, and codebook, are provided with the manuscript. Full qualitative datasets are not publicly available because of confidentiality concerns; de-identified data may be requested through the institutional contact at MUHAS as described in the article.
Ethical approvals and detailed author contributions were reported in the source article. The authors declared no competing interests.