Heart rate variability during hemodialysis is an indicator for long-term vascular access survival in uremic patients

Abstract

BackgroundVascular 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.MethodsThis 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.ResultsDuring 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.ConclusionsHRV is a useful tool for predicting long-term VAF among hemodialysis patients.

Heart rate variability as an independent predictor for 8-year mortality among chronic hemodialysis patients

“…In this point of view, the work of Chen et al 15 was constructive and worthy of more attention. However, the real dynamic changes of HRV during the hemodialysis process are likely to be a "reverse V-shape, " which denotes "increase at the initial stage but decreases at a later stage [16][17][18] . The HRV measurements at two time-points before and after hemodialysis could not demonstrate the real dynamic changes of HRV during the hemodialysis.…”

The Association between Nutritional Markers and Heart Rate Variability Indices in Patients Undergoing Chronic Hemodialysis

“…During hemodialysis, an adequate compensatory increase, especially in the sympathetic tone, indicates a better autonomic reserve and better survival [31]. On the other hand, an inadequate response predisposes patients to morbidities such as intradialytic hypotension and vascular access failure, or even mortality [18,19].…”

“…Lastly, poor nutritional status results from the interplay of many factors presented in patients undergoing chronic hemodialysis and causes significant morbidity and mortality. Our study has demonstrated an association between poor nutritional status and impaired autonomic function, which further contributes negatively to the prognoses among these patients [18,19,31]. (Figure 2)…”

“…In the current study, values of HRV indices were obtained using a 5 min measurement of an HRV analyzer (SSIC, Enjoy Research Inc., Taipei, Taiwan) which has been applied in many published studies [15,19,20,25]. After keeping quiet for more than 20 min, patients received the HRV measurement when they lay quietly and breathed normally for 5 min.…”

“…In CKD patients undergoing chronic hemodialysis, reduction of HRV is associated with higher morbidities, complications including vascular access failure and intradialytic hypotension, as well as higher mortality [18,19,20,21,22,23]. Nevertheless, the associations between HRV indices and nutritional markers have yet been adequately addressed in patients with CKD undergoing chronic hemodialysis.…”