HEMODIALYSIS VASCULAR ACCESS CLINICAL TRIALS CONSORTIUM

说明(改编自应用程序) 目前透析患者血管通路的方法包括 监测移植物和瘘管是否有狭窄的证据，并干预 在狭窄发生后纠正它。一种药物干预， 预防血管通路并发症可能会显著减少对 抢救程序、与接触相关的住院治疗以及 照顾血液透析患者。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高血压的危险因素 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。鉴于标准剂量 叶酸(每天1毫克)对同型半胱氨酸水平的影响微乎其微 透析患者，药物剂量(每天15毫克)可降低同型半胱氨酸 很大程度上。目前尚不清楚是否会积极削减 药物剂量叶酸对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频率。 本研究将检验以下假设：(1)药理剂量 每天15毫克的叶酸比标准剂量(每天1毫克)更有效 减少血液透析中移植物狭窄和血栓形成的发生率 病人。(2)大剂量叶酸对移植物预后的有益影响 与血浆同型半胱氨酸的下降幅度成正比。(3)偏高 剂量叶酸在改善移植物结果方面是有效的 一级预防(既往无狭窄或血栓形成)和二级预防 预防(预防初次手术后再狭窄或血栓形成 事件)。 研究设计为前瞻性、随机、双盲、多中心研究 接受房室移植的慢性血液透析患者将接受哪些治疗 随机接受高剂量(每天15毫克)或标准剂量(每天1毫克) 叶酸补充剂。主要终点将是移植物的总体存活率。 次要终点将是移植干预的频率和 心血管事件。结果将被分析，以确定是否有 在移植物存活率或并发症方面有显著差异 叶酸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.