title: Additive Value of Heart Rate Variability in Predicting Obstructive Coronary Artery Disease Beyond Framingham Risk.
abstract: BACKGROUND
  Heart rate variability (HRV) is usually reduced in patients with CAD. We therefore investigated whether reduced HRV is predictive of angiographic CAD beyond Framingham risk in patients with stable angina.
  
  
  RESULTS
  A total of 514 patients (age, 66.1 ± 14.3 years, 358 men) were enrolled. Holter ECG was performed before catheterization, and 24-h HRV was analyzed in both the frequency domain (VLF, LF, HF and total power) and the time domain (SDNN, SDANN, RMSSD and pNN20). Angiographic CAD was defined as ≥ 50% diameter reduction of 1 or more coronary arteries. On coronary angiography 203 patients (39.6%) had angiographic CAD. Patients with CAD had significantly higher Framingham risk and lower HRV according to both frequency and time domain parameters. After controlling for age, gender, heart rate, SBP, renal function, lipids and Framingham risk, reduced HRV indices remained predictors of CAD (OR, 95% CI for LF, HF, SDNN, RMSSD and pNN20: 0.81, 0.66-0.99; 0.77, 0.63-0.94; 0.75, 0.59-0.96; 0.72, 0.58-0.88; and 0.76, 0.62-0.94, respectively). On subgroup analysis, HRV parameters appeared to be predictive of CAD only in subjects with high Framingham risk or diabetes.
  
  
  CONCLUSIONS
  Reduced HRV is predictive of CAD in patients with stable angina, independent of traditional risk factors and Framingham risk. The predictive value of HRV may be relevant only in subjects with high Framingham risk or diabetes.
authors.affiliation: Department of Medicine, Shuang Ho Hospital, Taipei Medical University.
authors.forename: Hsin-Ru
authors.initials: HR
authors.lastname: Li
authors.forename: Tse-Min
authors.initials: TM
authors.lastname: Lu
authors.forename: Hao-Min
authors.initials: HM
authors.lastname: Cheng
authors.forename: Dai-Yin
authors.initials: DY
authors.lastname: Lu
authors.forename: Chuen-Wang
authors.initials: CW
authors.lastname: Chiou
authors.forename: Shao-Yuan
authors.initials: SY
authors.lastname: Chuang
authors.forename: Albert C
authors.initials: AC
authors.lastname: Yang
authors.forename: Shih-Hsien
authors.initials: SH
authors.lastname: Sung
authors.forename: Wen-Chung
authors.initials: WC
authors.lastname: Yu
authors.forename: Chen-Huan
authors.initials: CH
authors.lastname: Chen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D060050:Angina, Stable / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D012042:Registries