title: Blunted cyclic variation of heart rate predicts mortality risk in post-myocardial infarction, end-stage renal disease, and chronic heart failure patients.
abstract: OBJECTIVE
  Cyclic variation of heart rate (CVHR) associated with sleep-disordered breathing is thought to reflect cardiac autonomic responses to apnoeic/hypoxic stress. We examined whether blunted CVHR observed in ambulatory ECG could predict the mortality risk.
  
  
  RESULTS
  CVHR in night-time Holter ECG was detected by an automated algorithm, and the prognostic relationships of the frequency (FCV) and amplitude (ACV) of CVHR were examined in 717 patients after myocardial infarction (post-MI 1, 6% mortality, median follow-up 25 months). The predictive power was prospectively validated in three independent cohorts: a second group of 220 post-MI patients (post-MI 2, 25.5% mortality, follow-up 45 months); 299 patients with end-stage renal disease on chronic haemodialysis (ESRD, 28.1% mortality, follow-up 85 months); and 100 patients with chronic heart failure (CHF, 35% mortality, follow-up 38 months). Although CVHR was observed in ≥96% of the patients in all cohorts, FCV did not predict mortality in any cohort. In contrast, decreased ACV was a powerful predictor of mortality in the post-MI 1 cohort (hazard ratio [95% CI] per 1 ln [ms] decrement, 2.9 [2.2-3.7], P < 0.001). This prognostic relationship was validated in the post-MI 2 (1.8 [1.4-2.2], P < 0.001), ESRD (1.5 [1.3-1.8], P < 0.001), and CHF (1.4 [1.1-1.8], P = 0.02) cohorts. The prognostic value of ACV was independent of age, gender, diabetes, β-blocker therapy, left ventricular ejection fraction, sleep-time mean R-R interval, and FCV.
  
  
  CONCLUSIONS
  Blunted CVHR detected by decreased ACV in a night-time Holter ECG predicts increased mortality risk in post-MI, ESRD, and CHF patients.
authors: Department of Medical Education, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho Mizuho-ku, Nagoya 467-8601, Japan.
authors: Junichiro
authors: J
authors: Hayano
authors: Departments of Medicine, Suzuka National Hospital, Suzuka, Japan.
authors: Fumihiko
authors: F
authors: Yasuma
authors: Division of Cardiology, Department of Internal Medicine, Fujita Health University School of Medicine, Toyoake, Japan.
authors: Eiichi
authors: E
authors: Watanabe
authors: Department of Psychiatry, Washington University School of Medicine, St Louis, MO 63108, USA.
authors: Robert M
authors: RM
authors: Carney
authors: Departments of Medicine, Washington University School of Medicine, St Louis, MO 63108, USA.
authors: Phyllis K
authors: PK
authors: Stein
authors: Department of Psychiatry, Duke University Medical Center, Durham, NC 27710, USA.
authors: James A
authors: JA
authors: Blumenthal
authors: First Cardiology Division, University of Athens Medical School, Hippokration Hospital, Athens, Greece.
authors: Petros
authors: P
authors: Arsenos
authors: First Cardiology Division, University of Athens Medical School, Hippokration Hospital, Athens, Greece.
authors: Konstantinos A
authors: KA
authors: Gatzoulis
authors: Division of Medical Statistics, Fujita Health University, Toyoake, Japan.
authors: Hiroshi
authors: H
authors: Takahashi
authors: Department of Cardiology, Nagoya University, Nagoya, Japan.
authors: Hideki
authors: H
authors: Ishii
authors: School of Engineering Science, Osaka University, Suita, Japan.
authors: Ken
authors: K
authors: Kiyono
authors: Educational Physiology Laboratory, Graduate School of Education, University of Tokyo, Tokyo 113-0033, Japan.
authors: Yoshiharu
authors: Y
authors: Yamamoto
authors: Department of Medical Education, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho Mizuho-ku, Nagoya 467-8601, Japan.
authors: Yutaka
authors: Y
authors: Yoshida
authors: Department of Medical Education, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho Mizuho-ku, Nagoya 467-8601, Japan.
authors: Emi
authors: E
authors: Yuda
authors: Nagoya University, Nagoya, Japan.
authors: Itsuo
authors: I
authors: Kodama
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D000465:Algorithms; D002908:Chronic Disease; D002940:Circadian Rhythm; D015716:Electrocardiography, Ambulatory; D005260:Female; D006115:Greece; D006333:Heart Failure / Q000175:diagnosis / Q000401:mortality* / Q000503:physiopathology* / Q000628:therapy; D006339:Heart Rate; D006801:Humans; D007564:Japan; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000401:mortality* / Q000503:physiopathology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000401:mortality* / Q000503:physiopathology* / Q000628:therapy; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D006435:Renal Dialysis; D015203:Reproducibility of Results; D012307:Risk Factors; D012815:Signal Processing, Computer-Assisted; D013318:Stroke Volume; D013997:Time Factors; D016277:Ventricular Function, Left
chemical_list: D000319:Adrenergic beta-Antagonists
keywords: Ambulatory ECG; Heart rate; Holter ECG; Mortality; Risk stratification; Sleep apnoea