title: Use of T-wave alternans in identifying patients with coronary artery disease.
abstract: OBJECTIVE
  Microvolt T-wave alternans (MTWA) has been found to predict fatal events in patients with coronary artery disease (CAD). In a previous study, we found that MTWA values are higher in patients with CAD, compared with apparently healthy individuals. In this study, we assessed the relation between CAD and MTWA in patients with a diagnosis based on coronary angiography results.
  
  
  METHODS
  We studied 98 consecutive patients undergoing coronary angiography for suspected CAD. All patients underwent a maximal exercise stress test (EST), and MTWA was measured in the precordial ECG leads. Patients were divided into three groups: 40 patients without any significant (>50%) stenosis (group 1); 47 patients with significant stenosis (group 2); and 11 patients with a previous percutaneous coronary intervention (PCI) who had no evidence of restenosis (group 3). EST was repeated after 1 month in 24 group 2 patients who underwent PCI and in 17 group 1 patients.
  
  
  RESULTS
  MTWA was significantly higher in group 2 (58.7 ± 24 μV) compared with group 1 (34.2  ± 15 μV, P < 0.01) and group 3 (43.2 ± 24 μV, P < 0.05). An MTWA greater than 60 μV had 95% specificity and 82% positive predictive value for obstructive CAD. At 1-month follow-up, MTWA decreased significantly in patients treated with PCI (from 61.3 ± 22 to 43.5 ± 17 μV; P < 0.001), but not in group 1 patients (from 50.5 ± 22 to 44.3 ± 19 μV, P = 0.19).
  
  
  CONCLUSIONS
  MTWA is increased in patients with obstructive CAD and is reduced by coronary revascularization. An assessment of MTWA can be helpful in identifying which patients with suspected CAD are likely to show obstructive CAD on angiography.
authors.affiliation: Department of cardiovascular medicine, Università Cattolica del Sacro Cuore, Roma, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Figliozzi
authors.forename: Alessandra
authors.initials: A
authors.lastname: Stazi
authors.forename: Gaetano
authors.initials: G
authors.lastname: Pinnacchio
authors.forename: Marianna
authors.initials: M
authors.lastname: Laurito
authors.forename: Rossella
authors.initials: R
authors.lastname: Parrinello
authors.forename: Angelo
authors.initials: A
authors.lastname: Villano
authors.forename: Giulio
authors.initials: G
authors.lastname: Russo
authors.forename: Maria
authors.initials: M
authors.lastname: Milo
authors.forename: Roberto
authors.initials: R
authors.lastname: Mollo
authors.forename: Gaetano A
authors.initials: GA
authors.lastname: Lanza
authors.forename: Filippo
authors.initials: F
authors.lastname: Crea
mesh_terms: D000368:Aged; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000628:therapy; D023921:Coronary Stenosis / Q000175:diagnosis / Q000628:therapy; D004562:Electrocardiography / Q000379:methods; D005080:Exercise Test / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention