title: In-hospital heart rate turbulence and microvolt T-wave alternans abnormalities for prediction of early life-threatening ventricular arrhythmia after acute myocardial infarction.
abstract: BACKGROUND
  In the setting of primary prevention, most implantable cardiac defibrillators (ICD) are implanted more than 6 months after acute myocardial infarction (AMI). Abnormal heart rate turbulence (HRT) and T-wave alternans (TWA) are predictors of long-term sudden cardiac death (SCD). We intended to assess the predictive value of HRT and TWA for early post-AMI SCD and life-threatening ventricular arrhythmias (VA).
  
  
  METHODS
  One hundred ninety-nine consecutive patients with AMI were prospectively included (age 61.7 years, LV ejection fraction 45%). One hundred eighty-three patients (92%) underwent percutaneous coronary intervention. We assessed HRT using turbulence slope (TS), turbulence onset (TO), and TWA on channels 1 and 2 (TWA1 and TWA2) using the modified moving average method. Predictive performance for SCD/VA was assessed by area under the receiver operating curve characteristic (ROC-AUC).
  
  
  RESULTS
  Within 6 months after AMI, 2 patients (1%) developed life-threatening VA and 3 (1.5%) experienced SCD. TO and TWA1 had poor ROC-AUC (both 0.64) whereas TS and TWA2 failed to show any predictive performance (ROC-AUC 0.48 and 0.57, respectively). When combining TO and TWA1, ROC-AUC increased to 0.80. Importantly, when considering the subset of patients with a LV ejection fraction ≤40%, the combined variable of TO and TWA1 remained strongly predictive of a short-term event (ROC-AUC 0.86).
  
  
  CONCLUSIONS
  Combined assessment of HRT and TWA showed a high predictive performance for SCD or life-threatening VA within 6 months after AMI. This combined Holter ECG index could be useful to identify high-risk patients who might benefit from early ICD implantation.
authors.affiliation: Department of Rhythmology, Hospices Civils de Lyon, Louis Pradel Cardiovascular Hospital, Lyon, France.
authors.forename: Mohamed Moussa
authors.initials: MM
authors.lastname: Arisha
authors.forename: Nicolas
authors.initials: N
authors.lastname: Girerd
authors.forename: Samuel
authors.initials: S
authors.lastname: Chauveau
authors.forename: Didier
authors.initials: D
authors.lastname: Bresson
authors.forename: Alina
authors.initials: A
authors.lastname: Scridon
authors.forename: Eric
authors.initials: E
authors.lastname: Bonnefoy
authors.forename: Philippe
authors.initials: P
authors.lastname: Chevalier
mesh_terms: D000208:Acute Disease; D001145:Arrhythmias, Cardiac / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*; D016757:Death, Sudden, Cardiac / Q000517:prevention & control; D015716:Electrocardiography, Ambulatory / Q000379:methods*; D005260:Female; D006339:Heart Rate; D006801:Humans; D007297:Inpatients; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000503:physiopathology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve
keywords: T-wave alternans; acute myocardial infarction; heart rate turbulence; sudden death