title: Heart rate versus heart rate variability in risk prediction after myocardial infarction.
abstract: BACKGROUND
  The aim of this study was to evaluate and compare heart rate and heart rate variability (HRV) in risk prediction after acute myocardial infarction (MI) and to evaluate the effect of beta-blocker treatment on the prognostic performance of heart rate and HRV.
  
  
  RESULTS
  Three hundred sixty-six patients underwent 24-hour Holter recording 1 to 6 days after an MI. HRV was expressed as the standard deviation of all normal-to-normal intervals. Left ventricular systolic function was evaluated using the wall motion index. Half of the patients were taking a beta-blocker at the time of Holter recording. Mean follow-up was 44 months (median 34) after MI. By the end of follow-up, 82 patients had died. Mortality at 1 and 3 years was 12.5% and 22.6%, respectively. HRV, heart rate, wall motion index, number of ventricular premature beats per hour, and ventricular tachycardia were all significantly (P < 0.05) associated with mortality in univariate analysis, independent of beta-blocker therapy. In multivariate Cox analysis, only heart rate, wall motion index, number of ventricular premature beats per hour, and age had independent prognostic value (P < 0.001). In any model, including heart rate, HRV had no predictive value.
  
  
  CONCLUSIONS
  The prognostic information of HRV is contained completely in heart rate, which carries prognostic information further than that of HRV. This result was independent of beta-blocker treatment.
authors.affiliation: Department of Cardiology, Gentofte University Hospital, Copenhagen, Denmark.
authors.forename: Steen Z
authors.initials: SZ
authors.lastname: Abildstrom
authors.forename: Berit T
authors.initials: BT
authors.lastname: Jensen
authors.forename: Erik
authors.initials: E
authors.lastname: Agner
authors.forename: Christian
authors.initials: C
authors.lastname: Torp-Pedersen
authors.forename: Ole
authors.initials: O
authors.lastname: Nyvad
authors.forename: Kristian
authors.initials: K
authors.lastname: Wachtell
authors.forename: Michael M
authors.initials: MM
authors.lastname: Ottesen
authors.forename: Jørgen K
authors.initials: JK
authors.lastname: Kanters
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004562:Electrocardiography / Q000379:methods; D015716:Electrocardiography, Ambulatory / Q000379:methods*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000188:drug therapy / Q000401:mortality*; D011379:Prognosis; D018570:Risk Assessment / Q000379:methods*; D013223:Statistics as Topic
chemical_list: D000319:Adrenergic beta-Antagonists