Dietary Vitamin K Restriction and Effectiveness of Vitamin K Antagonists Prescribed at the CNHU-HKM University Cardiology Clinic/BENIN

Introduction: Their efficacy in preventing thrombotic and embolic events has been proven in numerous studies, but their narrow therapeutic index requires particular vigilance, especially in terms of biology. In addition, treatment-related hemorrhagic complications are not uncommon. This study explores the influence of dietary vitamin K restriction on the efficacy of antivitamin K treatment at the University Cardiology Clinic of CNHU-HKM. Methods: Cross-sectional and descriptive study that took place from 25 April to 29 August 2019. Patients’ dietary behaviors and successive INR values were collected. Information on dietary intake was obtained by 2 non-consecutive 24-hour recalls. The effectiveness of VKA treatment was assessed by the “Time in Therapeutic Range” (TTR) of the INR. VKA treatment was considered effective for a TTR greater than 65%. Results: At the end of this study, 40 patients were surveyed. The mean age of the participants was 58.05 years ± 13.32 years, with a sex ratio of 1.35. Complete arrhythmia due to atrial fibrillation was the main indication for VKA treatment (37.50%) and fluindione was the most commonly prescribed drug (77.50%). The duration of treatment was less than or equal to 2 years in 47.5% of the subjects surveyed. Before starting treatment, 85% of patients received advice on restricting vitamin K-rich foods, and 45% of patients reported “food burnout” after a period of compliance with the restriction. The majority of respondents (97.50%) complied with the restriction on vitamin K-rich foods. All respondents had high energy intakes and a poor distribution of macronutrients, with a predominance of carbohydrates and proteins. 2.5% of respondents were on effective anti-vitamin K therapy with a TTR of over 65%. Conclusion: Restriction of vitamin K-rich foods is not conducive to effective treatment with vitamin K antagonists.