Optimizing the Laboratory’s Role in Monitoring Vitamin K Antagonist Therapy: A Cross-Analysis at Hôpital de la Paix de Ziguinchor

Abstract

Introduction: Vitamin K Antagonist are large molecular therapy used in Africa to treat cardiologic illnesses .The aim of this study was  to evaluate how the clinical laboratory supports safe and effective monitoring of patients on vitamin K antagonists (VKAs) at Hôpital de la Paix de Ziguinchor (HPZ), through analysis of patient INR profiles, laboratory practices, and prescribers’ perceptions. Methodology: We have conducted a Monocentric, mixed-methods, descriptive cross-sectional study from November 2024 to January 2025 in the cardiologic ward and the laboratory of the HPZ, Ziguinchor. Thirty-three cardiology outpatients on VKAs (N=33) were analyzed with two sequential INR measurements (INR1, INR2). Associations with demographics used χ² tests; paired comparisons used paired t-test and Wilcoxon. Structured questionnaires captured laboratory staff practices (n=9) and prescribers’ perceptions (n=13). Results: The cohort was predominantly female (57.6%); mean age 50.0 ± 20.0 years (16–79). From INR1 to INR2, subtherapeutic results decreased (14→10) while supratherapeutic results increased (11→16). No significant paired difference overall (t-test p=0.2403; Wilcoxon p=0.3775). No significant association between INR status and age group or sex (p=0.0737; p=0.0934). Staff highlighted pre-analytical vulnerabilities and training needs; clinicians prioritized faster reporting, clearer interpretive comments, and stronger communication. Conclusion: VKA monitoring at HPZ shows partial short-term stabilization with a sizeable supratherapeutic fraction. Priorities include tightening pre-analytical control, securing reagent/analyzer continuity, upskilling staff, and codifying rapid critical-INR communication to increase time in therapeutic range and reduce adverse events.