title: Heart rate variability during hemodialysis is an indicator for long-term vascular access survival in uremic patients.
abstract: BACKGROUND
  Vascular access (VA) is the lifeline of hemodialysis patients. Although the autonomic nervous system might be associated with VA failure (VAF), it has never been addressed in previous studies. This study aimed to evaluate the predictive values of the heart rate variability (HRV) indices for long-term VA outcomes.
  
  
  METHODS
  This retrospective study was conducted using a prospectively established cohort enrolling 175 adult chronic hemodialysis patients (100 women, mean age 65.1 ± 12.9 years) from June 2010 to August 2010. Each participant received a series of HRV measurements at enrollment. After a 60-month follow-up period, we retrospectively reviewed all events and therapeutic procedures of the VAs which existed at the enrollment and during the follow-up period.
  
  
  RESULTS
  During the 60-month follow-up period, 37 (26.8%) had VAF but 138 (73.2%) didn't. The values of most HRV indices were statistically increased during hemodialysis since initiation in the non-VAF group, but not in the VAF group. Among all participants, the independent indicators for VAF included higher normalized high-frequency (nHF) activity [hazard ratio (HR) 1.04, p = 0.005], lower low-frequency/high-frequency (LF/HF) ratio (HR 0.80, p = 0.015), experience of urokinase therapy (HR 11.18, p = 0.002), percutaneous transluminal angioplasty (HR 2.88, p = 0.003) and surgical thrombectomy (HR 2.36, p = 0.035), as well as higher baseline serum creatinine (HR 1.07, p = 0.027) and potassium level (HR 1.58, p = 0.037). In subgroup analysis, a lower sympathetic activity indicated by lower LF/HF ratio was an independent indicator for VAF (HR 0.61, p = 0.03) for tunneled cuffed catheter, but conversely played a protective role against VAF (HR 1.27, p = 0.002) for arteriovenous fistula.
  
  
  CONCLUSIONS
  HRV is a useful tool for predicting long-term VAF among hemodialysis patients.
authors.affiliation: Graduate Institute of Clinical medical sciences, Chang Gung University, Taoyuan City, Taiwan (R.O.C.).|Department of Nursing, Saint Mary's hospital Luodong, Yilan, Taiwan (R.O.C.).
authors.forename: Ya-Ting
authors.initials: YT
authors.lastname: Huang
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Saint Mary's hospital Luodong, Yilan, Taiwan (R.O.C.).
authors.forename: Yu-Ming
authors.initials: YM
authors.lastname: Chang
authors.affiliation: Department of Nursing, Saint Mary's hospital Luodong, Yilan, Taiwan (R.O.C.).
authors.forename: I-Ling
authors.initials: IL
authors.lastname: Chen
authors.affiliation: Department of Nursing, Saint Mary's hospital Luodong, Yilan, Taiwan (R.O.C.).
authors.forename: Chuan-Lan
authors.initials: CL
authors.lastname: Yang
authors.affiliation: Department of Nursing, Saint Mary's hospital Luodong, Yilan, Taiwan (R.O.C.).
authors.forename: Show-Chin
authors.initials: SC
authors.lastname: Leu
authors.affiliation: Department of Nursing, Saint Mary's hospital Luodong, Yilan, Taiwan (R.O.C.).
authors.forename: Hung-Li
authors.initials: HL
authors.lastname: Su
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Saint Mary's hospital Luodong, Yilan, Taiwan (R.O.C.).
authors.forename: Jsun-Liang
authors.initials: JL
authors.lastname: Kao
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Saint Mary's hospital Luodong, Yilan, Taiwan (R.O.C.).
authors.forename: Shih-Ching
authors.initials: SC
authors.lastname: Tsai
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Saint Mary's hospital Luodong, Yilan, Taiwan (R.O.C.).
authors.forename: Rong-Na
authors.initials: RN
authors.lastname: Jhen
authors.affiliation: Graduate Institute of Nursing, Chang Gung University, Taoyuan City, Taiwan (R.O.C.).
authors.forename: Woung-Ru
authors.initials: WR
authors.lastname: Tang
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Saint Mary's hospital Luodong, Yilan, Taiwan (R.O.C.).|Saint Mary's Medicine, Nursing and Management College, Yilan, Taiwan (R.O.C).
authors.forename: Chih-Chung
authors.identifier: http://orcid.org/0000-0003-2220-7574
authors.initials: CC
authors.lastname: Shiao
mesh_terms: D000368:Aged; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D015996:Survival Rate; D014511:Uremia / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D062666:Vascular Access Devices