title: The role of variability in night-time mean heart rate on the prediction of ventricular arrhythmias and all-cause mortality in implantable cardioverter defibrillator patients.
abstract: OBJECTIVE
  This study was to use implantable cardioverter defibrillator (ICD) home monitoring (HM) feature to evaluate the role of mean night-time heart rate (MNHR) in the occurrence of ventricular arrhythmias (VAs) and mortality.
  
  
  RESULTS
  This study retrospectively analysed clinical and ICD device data in 318 ICD patients. Data of the first 30-day MNHR (recorded 02:00-06:00 am) by HM were collected. The average and standard deviation of 30-day MNHR (AVHR and SDHR, respectively) were then determined in each patient. The primary endpoint was appropriate ICD treatment of VAs. The secondary endpoint was all-cause mortality. During a mean follow-up period of 32 ± 10 months, 179 of the 318 patients (56.3%) experienced VAs, 123 patients (38.7%) were treated by ICD shocks, and 37 patients (11.6%) died. The overall SDHR in this study cohort was 4.5 ± 3.0 bpm. Based on the receiver operating characteristic curve, the cut-off value of SDHR = 3.685 bpm was identified to predict VAs. In the Kaplan-Meier survival, SDHR ≥ 3.685 bpm was associated with increased VAs [hazard ratio (HR) = 1.885; 95% confidence interval (CI) = 1.362-2.609; P < 0.001], shock events (HR = 1.637; 95% CI = 1.11-2.414; P = 0.013), all-cause mortality (HR = 2.42; 95% CI = 1.266-4.627; P = 0.008), and the combined endpoints (HR = 1.872; 95% CI = 1.365-2.567; P < 0.001). In univariate and multivariate Cox models (adjusting for clinical factors), SDHR ≥ 3.685 bpm was still an independent predictor for all endpoints.
  
  
  CONCLUSIONS
  In ICD population, SDHR ≥ 3.685 bpm was an independent predictor for VAs and all-cause mortality.
authors: State Key Laboratory of Cardiovascular Disease, Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
authors: Shuang
authors: S
authors: Zhao
authors: State Key Laboratory of Cardiovascular Disease, Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
authors: Keping
authors: K
authors: Chen
authors: Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, PR China.
authors: Yangang
authors: Y
authors: Su
authors: State Key Laboratory of Cardiovascular Disease, Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
authors: Wei
authors: W
authors: Hua
authors: State Key Laboratory of Cardiovascular Disease, Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
authors: Jielin
authors: J
authors: Pu
authors: Beijing Hui Kang Xin Technology Co., Ltd, Beijing, PR China.
authors: Hui
authors: H
authors: Li
authors: State Key Laboratory of Cardiovascular Disease, Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
authors: Yan
authors: Y
authors: Dai
authors: State Key Laboratory of Cardiovascular Disease, Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
authors: Min
authors: M
authors: Tang
authors: State Key Laboratory of Cardiovascular Disease, Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
authors: Xiaohan
authors: X
authors: Fan
authors: State Key Laboratory of Cardiovascular Disease, Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
authors: Yunzi
authors: Y
authors: Zhao
authors: State Key Laboratory of Cardiovascular Disease, Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
authors: Xiaolin
authors: X
authors: Zheng
authors: State Key Laboratory of Cardiovascular Disease, Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
authors: Chi
authors: C
authors: Cai
authors: State Key Laboratory of Cardiovascular Disease, Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
authors: Zeyi
authors: Z
authors: Li
authors: State Key Laboratory of Cardiovascular Disease, Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China zsfuwai@vip.163.com.
authors: Shu
authors: S
authors: Zhang
mesh_terms: D002681:China / Q000453:epidemiology; D015897:Comorbidity; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D003936:Diagnosis, Computer-Assisted / Q000379:methods; D015716:Electrocardiography, Ambulatory / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis; D016016:Proportional Hazards Models; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012680:Sensitivity and Specificity; D015996:Survival Rate; D017180:Tachycardia, Ventricular / Q000401:mortality* / Q000517:prevention & control*; D014693:Ventricular Fibrillation / Q000401:mortality* / Q000517:prevention & control*
keywords: Heart rate variability; Home monitoring; Implantable cardioverter defibrillator; Night-time heart rate; Ventricular arrhythmias