A Phase III Pilot RCT (Randomized, Controlled Trial) to Assess the Effectiveness of Low Dose Vitamin K1 (200 Micrograms Per Day) on Improving Anticoagulation Control in Unstable Patients on Warfarin
试验速览
- 阶段
- 3 期
- 状态
- 已完成
- 入组人数
- 100
- 试验地点
- 2
- 主要终点
- Anticoagulation control -- Point estimates (and standard deviations) for the following variables: Percent time in therapeutic range, standard deviation of INRs, number of INRs outside of therapeutic range, and number of dose changes
研究概览
简要总结
The main objective of this study is to assess the effectiveness of low dose Vitamin K1 (200 micrograms per day) at improving anticoagulation control in unstable patients on warfarin. This study will also aim to look at effectiveness in the context of genes known to influence warfarin metabolism, variability in the consumption of Vitamin K rich foods, and patient knowledge about warfarin anticoagulation -- factors which have been associated with anticoagulation control and which can influence the effectiveness of this intervention in clinical practice.
详细描述
A double-blinded placebo controlled pilot RCT assessing the effectiveness of daily supplementation with low dose Vitamin K1 (200 micrograms per day) against placebo at improving anticoagulation control. Previous studies assessing the efficacy of this intervention have been small and further trials are required to evaluate the true effectiveness and safety profile. Furthermore the impact of genetic polymorphisms, known to impact warfarin metabolism, on the effectiveness/safety of this intervention will also be assessed in this study. Demographic and clinical variables as well as potential confounding variables such as variable dietary Vitamin K intake, concomitant interacting medications, and anticoagulation knowledge will be assessed in this study. Given that this is a pilot study we will be looking at recruitment numbers and necessary parameter estimates to determine the number of patients available at our institution for the study. Power analysis will be performed to evaluate the treatment effect size between the placebo and intervention groups.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •>= 18 years old
- •Have been on warfarin anticoagulation for at least 9 months
- •Have an INR target range of 2.0-3.0
- •Have "unstable" anticoagulation control, defined as in the preceding 6 months having at least 3 INRs out of range (>= 3.2 or =<1.8) or at least 3 warfarin dose changes
- •Have anticoagulation managed by the Ottawa Hospital Thrombosis Clinic
- •Able to provide written, informed consent
排除标准
- •Anticipated interruption or termination of warfarin anticoagulation in the next six months for a period of 1 week or greater
- •Patient instability in the preceding six months suspected to be due to a) Interruption of warfarin therapy for a period of 1 week or more or b) Significant non-compliance (assessed from patient record)
- •Possess a known allergy to Vitamin K or lactose based placebos
- •Unable/Refusal to provide written, informed consent
结局指标
主要结局
Anticoagulation control -- Point estimates (and standard deviations) for the following variables: Percent time in therapeutic range, standard deviation of INRs, number of INRs outside of therapeutic range, and number of dose changes
时间窗: At study initiation (for the six month pre-intervention period) and at study completion (after the six-month intervention period)
Recruitment Numbers -- Number of patients deemed eligible, Number of patients solicited, Number of patients screened, Number of patients enrolled, and Number of enrolled patients lost to follow-up
时间窗: Monthly
次要结局
- Bleeding Events -- Both major and minor as defined by the International Society on Thrombosis and Haemostasis (ISTH) criteria(Over 6 month study period)
- Recurrent thrombosis(Over six month study period)