Assessment of Oral Anticoagulation with Vitamin K Antagonists in Patients Living in a Low-Income Country of West Africa

Introduction: Despite the rise of direct oral anticoagulants (DOACs), vitamin K antagonists (VKA) remain the most widely used oral anticoagulants in developing countries. The aim of this study was to estimate the prevalence of good anticoagulation in patients treated with VKA in Lomé and describe associated factors. Methods: This was a cross-sectional study conducted from November 2019 to October 2020 in the cardiology departments of two University teaching hospitals in Lomé (CHU Sylvanus Olympio and CHU Campus), involving patients on VKA for ≥3 months, with a target international normalized ratio (INR) of 2.5 and a therapeutic margin between 2 and 3. The quality of anticoagulation was assessed by the time in therapeutic range (TTR) which was assessed by the Rosendaal method. Good anticoagulation was defined by a TTR > 70%. Results: A total of 344 patients were included (mean age = 58 ± 13.8 years, women = 56.1%). Indications for VKA treatment were represented by venous thromboembolic disease (43.3%), supraventricular arrhythmia (28.2%), severe left ventricular systolic dysfunction (19.8%) and pulmonary hypertension (8.7%). The average TTR was 47.6 ± 20.8%. The rate of good anticoagulation was 17.7%. Factors associated with good anticoagulation were the use of fluindione vs acenocoumarol (OR = 11.17;95% CI: 3.2 - 39.6;p = 0.0002), concomitant low-dose aspirin (OR 4.44;95% CI: 1.4 - 13.9;p = 0.01) and INR monitoring exclusively by the patient himself (OR = 4.92;95% CI: 1.5 - 16.3;p = 0.008). The rate of thromboembolic and hemorrhagic complications was each 2.6% and was not correlated with the quality of anticoagulation. Quality of anticoagulation by VKAs was poor in our practice. Factors associated with good anticoagulation were the use of fluindione vs acenocoumarol, concomitant low-dose aspirin and monitoring of INR exclusively by the patient himself. Conclusion: The quality of oral anticoagulation by VKAs could be improved in our practice by the creation of anticoagulation clinics for better therapeutic education of patients and efficient management of VKA dose, and the use of prescription assistance software.

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.

蛇毒血凝酶联合维生素K 1治疗新生儿消化道出血的临床效果

目的观察蛇毒血凝酶联合维生素K 1治疗新生儿消化道出血的临床效果。方法回顾性分析2022年3月—2024年3月福建医科大学附属三明第一医院收治的75例新生儿消化道出血患儿临床诊疗资料,以治疗方案不同分为观察组(38例)和对照组(37例)。在常规治疗基础上,对照组单纯予维生素K 1注射液治疗,观察组在对照组基础上加用蛇毒血凝酶注射液治疗,2组均治疗3 d。比较2组治疗效果,呕血、血便、腹胀等症状改善及粪便隐血试验转阴时间,治疗前1 d、治疗后3 d凝血功能指标[纤溶酶原激活物抑制剂-1(PAI-1)、凝血酶时间(TT)、活化部分凝血活酶时间(APTT)、纤维蛋白原(Fib)、D-二聚体(D-D)、组织型纤溶酶原激活物(t-PA)]水平及不良反应。结果观察组患者治疗总有效率为97.37%,高于对照组的83.78%(χ2=4.088,P=0.043);观察组呕血、血便、腹胀等症状改善及粪便隐血试验转阴时间均短于对照组(P<0.01)。治疗后3 d,2组TT、APTT、t-PA较治疗前缩短或降低,其余指标升高(PAI-1对照组内比较无差异),且观察组降低或升高程度均大于对照组(P<0.05或P<0.01)。观察组不良反应总发生率为5.26%,低于对照组的21.62%(χ2=4.341,P=0.037)。结论蛇毒血凝酶联合维生素K 1治疗新生儿消化道出血的临床效果肯定,可有效改善症状与凝血功能指标,且用药安全性高。

心房颤动患者口服抗凝剂疗效指标选择的系统评价

目的:了解心房颤动(房颤)患者口服抗凝剂治疗过程中抗凝效果的疗效观察指标应用情况,比较不同疗效观察指标的优缺点及适用性。方法:运用Cochrane系统评价方法,检索MEDLINE,EMBASE和Cochrane Library近10年(1998年1月～2008年1月)关于口服抗凝剂(调整剂量华法林)疗效控制指标的文献进行系统评价。相关指标包括:在抗凝目标值范围内的时间百分比(percentage of time in therapeutic range,TTR),在抗凝目标值范围内的国际标准化比值(INR)百分比等。结果:根据纳入排除标准入选文献50篇,共计68个研究组。研究样本量从25例到6 454例不等(平均757例);研究或随访时间最短3个月,最长42个月(中位数12个月)。使用最多的抗凝控制指标为TTR[占研究总数69%(45/65)]和抗凝目标值范围内的INR百分比[占研究总数37%(24/65)]。仅有9%(6/65)的研究同时采用以上两种指标,两指标间差别有统计学意义[(59±13)%vs.(53±10)%,P=0.002],同时有显著直线相关关系(r=0.988,P<0.001)。结论:TTR和抗凝目标值范围内的INR百分比是目前最常用的抗凝控制指标。相关研究可以同时采用这两种指标,并结合其他指标使用,以弥补相互不足便于抗凝监控和比较。