TITLE: Delayed conversion from central venous catheter to non-catheter hemodialysis access associates with an increased risk of death: A retrospective cohort study based on data from a large dialysis provider.

BACKGROUND: Hemodialysis initiation using a central venous catheter (CVC) poses an increased risk of death. Conversion to an arterio-venous graft or fistula (AVF, AVG) improves outcomes. The relationship of primary dialysis access and timing of conversion from CVC to either AVF or AVG to all-cause mortality was investigated.

METHODS: Two retrospective analyses in incident hemodialysis patients commencing treatment from January 2010 to December 2014 in dialysis clinics in the United States were conducted. Analysis 1 stratified as per access at initiation and those commencing with CVC were further stratified into (a) those that had a CVC, AVF, or AVG the entire year; (b) those that were converted to either AVF or AVG within either (i) the first or (ii) the second 6 months. Kaplan Meier analysis and Cox regression analysis were employed. Analysis 2 included all CVC patients investigating the relationship between access conversion time and mortality risk using a Cox proportional hazards model depicting the hazard ratio (HR) as a spline function over time.

RESULTS: Two subsets from initial 78,871 patients were studied. In Analysis 1 both AVF (referent) and AVG [HR 1.12 (0.97 to 1.30)] associated with a better outcome than CVC [HR 1.55 (1.38 to 1.74)] during follow-up. Lower mortality risk was seen for early switch from a CVC to AV access within the first 6 months [HR = 1.04 (0.97-1.13)] compared to a later switch [HR = 1.23 (1.10-1.38)]. Analysis 2 indicated that a CVC to AVF switch resulted in improved survival. Analysis 2 indicated early conversion to confer a survival benefit for CVC to AVG switch.

DISCUSSION AND CONCLUSION: AVF and AVG show a survival benefit over CVC. Early conversion from CVC to either access improves survival. This emphasizes the importance of early preparation for dialysis by creation of an AVF or AVG and to convert CVCs early.

SOURCE: Raimann JG, Chu FI, Kalloo S, et al. Delayed conversion from central venous catheter to non-catheter hemodialysis access associates with an increased risk of death: A retrospective cohort study based on data from a large dialysis provider[J]. Hemodial Int, 2020, 24(3):299-308. DOI: 10.1111/hdi.12831. 

背景：使用中央静脉导管（CVC）进行血液透析会增加死亡风险。转换为动静脉移植物或瘘管（AVF，AVG）可改善结局。研究了初次透析通路和从CVC转换为AVF或AVG到全因死亡率的时间之间的关系。

方法：对2010年1月至2014年12月在美国透析诊所开始治疗的血液透析患者进行了两项回顾性分析。分析1按开始时的访问进行分层，从CVC开始的访问被进一步分层为（a）全年具有CVC，AVF或AVG的访问； （b）在（i）前六个月或（ii）后六个月内转换为AVF或AVG。使用Kaplan Meier分析和Cox回归分析。分析2包括所有CVC患者，他们使用Cox比例风险模型调查访问转化时间与死亡风险之间的关系，该模型描述了风险比率（HR）作为随时间变化的函数。

结果：研究了来自最初的78,871例患者的两个亚组。在分析1中，AVF（参考）和AVG [HR 1.12（0.97至1.30）]的随访结果均优于CVC [HR 1.55（1.38至1.74）]。与前一个转换（HR = 1.23（1.10-1.38））相比，在前6个月内从CVC早期转换为AV访问的死亡率风险较低[HR = 1.04（0.97-1.13）]。分析2表明，从CVC到AVF的转换可提高生存率。分析2指出，尽早转换可为CVC到AVG转换带来生存优势。

讨论与结论：AVF和AVG较CVC具有生存优势。从CVC早期转换为两种通路都可以提高生存率。这强调了通过创建AVF或AVG以及尽早转换CVC进行透析的早期准备的重要性。

启发：从转换的角度去思考AVF或AVG的价值。