Abstract 14139: Nocturnal Dysregulation of Heart Rate is Associated with Cardiovascular and All-cause Mortality in End-stage Renal Disease Patients on Hemodialysis
Background: It has been established that elevated resting heart rate (HR) is associated with cardiovascular (CV) morbidity and mortality, besides, some reports have described that blunted nocturnal dipping of HR, which may be due to sympathetic-parasympathetic imbalance, independently predicts the poor survival in general population. On the other hand, CV disease is a leading cause of death in patients on hemodialysis (HD), however, the association between CV mortality and the nocturnal HR regulation is little known in this population. We investigated whether the amplitudes of nocturnal HR dipping could predict CV and all-cause mortality in HD patients.
Methods: A total of 309 HD patients (male 55%, age 63±11years, diabetes 46%) underwent 24hr ambulatory Holter ECG monitoring during inter-dialysis day. From obtained mean diurnal HR and mean nocturnal HR during each periods based on ambulatory recording described by patients themselves, diurnal-nocturnal HR dipping ratios were calculated as following; (mean diurnal HR - mean nocturnal HR) / mean diurnal HR x 100. They were divided into tertiles according to the percentage reduction of HR levels; <5.4% (T1, n=103), 5.4–11.7% (T2, n=103) and >11.7% (T3, n=103). They were followed up for 8years.
Results: During follow-up period (75±25months), 88 patients (28.6%) died including 36 CV death (11.7%). Eight-year event-free survival rates were 76.9%, 89.6% and 93.2% for CV mortality (p=0.0013), and were 60.4%, 68.1% and 81.0% for all-cause mortality in the groups of T1, T2 and T3 (p=0.0018), respectively. After adjustment for gender, age, diabetes, hypertension, hyperlipidemia, smoking, history of CV disease, hemoglobin, albumin and C-reactive protein, the reduction of HR dipping was an independent predictor for CV mortality [hazard ratio (HR) 3.31, 95% confidential interval (CI) 1.31–8.34 for T1 vs. T3, p=0.011] and for all-cause mortality (HR 2.13, 95%CI 1.20–3.67 for T1 vs. T3, p=0.035), respectively. Neither diurnal HR nor nocturnal HR was associated with the mortality.
Conclusions: Nocturnal dysregulation of HR expressed as the reduction of HR dipping, which may be possibly explained by the abnormalities in autonomic regulation, was strongly associated both CV and all-cause mortality in HD patients.
- © 2010 by American Heart Association, Inc.