HEMODIALYSIS VASCULAR ACCESS CLINICAL TRIALS CONSORTIUM

描述（改编自应用程序） 目前透析患者血管通路的方法包括 监测移植物和瘘管的狭窄证据，并进行干预， 在狭窄发生后进行纠正。药物干预， 预防血管通路并发症可显著降低 挽救手术、与入路相关的住院治疗以及 护理血液透析患者。血浆同型半胱氨酸水平经常 在透析患者中升高。高同型半胱氨酸血症是 血液透析患者的心血管疾病，也可能是一个危险因素 用于血管通路血栓形成叶酸是同型半胱氨酸的底物， 服用叶酸可以降低同型半胱氨酸水平。而标准剂量 叶酸（每天1毫克）对高半胱氨酸水平的影响很小， 透析患者，药理剂量（每日15 mg）可降低同型半胱氨酸 水平相当。目前尚不清楚是否积极减少 叶酸对血液透析患者同型半胱氨酸水平的影响 可降低血管通路狭窄和血栓形成的发生率。 本研究将检验以下假设：（1）药理学剂量 叶酸（每天15毫克）比标准剂量（每天1毫克）更有效 降低血液透析中移植物狭窄和血栓形成的频率 患者(2)高剂量叶酸对移植结果的有益作用 与血浆同型半胱氨酸降低的幅度成比例。(3)高 剂量叶酸管理是有效的，在改善移植结果， 一级预防（既往无狭窄或血栓形成）和二级预防 预防性治疗（预防初次治疗后再狭窄或血栓形成） 事件）。 研究设计为前瞻性、随机、双盲、多中心 在一项研究中，患有AV移植物的慢性血液透析患者将 随机接受高剂量（每日15 mg）或标准剂量（每日1 mg） 叶酸补充剂。主要终点为移植物总生存率。 次要终点是移植物干预的频率， 心血管事件。将对结果进行分析，以确定是否存在 在移植物存活率或并发症方面， 高剂量组和标准剂量组。

DESCRIPTION (adapted from the application) The current approach to vascular access in dialysis patients consists of monitoring grafts and fistulas for evidence of stenosis, and intervening to correct the stenosis after it occurs. A pharmacologic intervention that prevents vascular access complications may markedly decrease the need for salvage procedures, access-related hospitalizations, and the overall cost of caring for hemodialysis patients. Plasma homocysteine levels are frequently elevated in dialysis patients. Hyperhomocysteinemia is a risk factor for cardiovascular disease in hemodialysis patients, and may also be a risk factor for vascular access thrombosis. Folate is a substrate for homocysteine, and folic acid administration can lower homocysteine levels. Whereas standard doses of folic acid (1 mg daily) have a minimal effect on homocysteine levels in dialysis patients, pharmacologic doses (15 mg daily) can reduce homocysteine levels substantially. It is not known whether aggressive reduction of homocysteine levels in dialysis patients with pharmacologic doses of folic acid can decrease the frequency of vascular access stenosis and thrombosis. The following hypotheses will be tested in this study: (1) Pharmacologic doses of folic acid (15 mg daily) are more effective than standard doses (1 mg daily) in decreasing the frequency of graft stenosis and thrombosis in hemodialysis patients. (2) This beneficial effect of high-dose folic acid on graft outcome is proportionate to the magnitude of reduction in plasma homocysteine. (3) High dose folic acid administration is effective in improving graft outcomes both as primary prophylaxis (no previous stenosis or thrombosis) and as secondary prophylaxis (prevention of recurrent stenosis or thrombosis after an initial event). The study design is a prospective, randomized, double-blind, multicenter investigation in which chronic hemodialysis patients with AV grafts will be randomized to receive either high (15 mg daily) or standard (1 mg daily) doses of folic acid supplements. The primary endpoint will be overall graft survival. Secondary endpoints will be the frequency of graft interventions and cardiovascular events. The results will be analyzed to determine whether there are significant differences in graft survival or complications between the groups receiving high dose and standard dose of folic acid.