Risk Factors Of Arteriovenous Fistula Failure In Elderly Hemodialysis Patients:Application Of Competing Risk Model

BackgroundWith an aging society,the proportion of elderly maintenance hemodialysis(MHD)patients is increasing yearly.Due to poor vascular conditions in elderly MHD patients,autologous arteriovenous fistula(AVF)dysfunction is more likely to be observed.Currently,there were many studies on AVF dysfunction for general MHD patients,but studies on elderly MHD patients were still rare.The Geriatric Nutritional Risk Index(GNRI),as a simple nutritional assessment tool,has been suggested in recent years related to inflammation and the risk of cardiovascular death,but whether it is also related to AVF dysfunction is still a blank.ObjectivesOur study was to investigate the risk factors of AVF dysfunction in elderly MHD patients in our center and whether the simple nutrition assessment tool GNRI was related to AVF dysfunction.MethodIt was a single-center and retrospective study.The cohort study included elderly patients(≥65 years of age)who were undergoing MHD with AVF in our center,Guangzhou Red Cross Hospital Affiliated to Jinan University,from January 01,2010 to November 30,2019.Clinical and biochemical data at baseline from MHD patients who met with inclusion criteria were collected when AVF-surgery hospitalization.Clinical endpoints were defined as death and the first episode of AVF dysfunction respectively,and the risk factors of all-cause mortality and the first episode of AVF dysfunction in elderly MHD patients were analyzed by the COX regression models.The Kaplan-Meier survival curve and log-rank test were used to analyze the association factors of AVF survival time in elderly MHD patients in the AVF dysfunction group.With the competitive risk of death,the cumulative risk model and Gray test were used to estimate the cumulative incidence rate of AVF dysfunction,and a partial distribution proportional hazard regression model was used in order to confirm the independent association factors of the first episode of AVF dysfunction.Results(1)In elderly MHD patients,age,cardiovascular disease,higher baseline MPV,lower BUN,and higher baseline CRP were associated with all-cause mortality,and age was the only independent risk factor for all-cause death.(2)Univariate Cox regression analysis showed that diabetes,hypertension,higher level of PDW,RDW,WBC,CRP,lower level of serum Chloride,GNRI,BMI,serum albumin and prealbumin at baseline were associated with the first stage of AVF dysfunction in elderly MHD patients.Multivariate Cox regression model and traditional survival analysis indicated that hypertension,diabetes,lower Chloride level,GNRI <84.583 and higher RDW at baseline were independent risk factors for the first episode of AVF dysfunction.(3)The competitive risk model indicated that the cumulative incidence of first episode AVF dysfunction in elderly patients was associated with hypertension,lower GNRI,serum Chloride levels and higher WBC,N and RDW at baseline.Among them,hypertension,GNRI <84.583,and lower serum Chloride level were independent risk factors for the cumulative incidence rate of the first episode AVF dysfunction in elderly MHD patients.SummaryAge was an independent risk factor for all-cause mortality in elderly MHD patients.Lower serum Chloride and GNRI level at baseline might be predictive factors for the first episode of AVF dysfunction in elderly MHD patients.This might suggest that improving the nutritional status and increasing serum Chloride level of elderly MHD patients may improve long-term survival of AVF in elderly MHD patients,but prospective study with larger sample size still need.