title: Clinical implications of QRS duration and QT peak prolongation in patients with suspected coronary disease referred for elective cardiac catheterization.
abstract: BACKGROUND
  The electrocardiogram (ECG) remains a simple, universally available, and prognostically powerful investigation in heart failure, and acute coronary syndromes. We sought to assess the prognostic utility of clinical, angiographic, and simple ECG parameters in a large cohort of patients undergoing elective cardiac catheterization (CC) for known or suspected coronary artery disease.
  
  
  METHODS
  Consecutive consenting patients undergoing CC for coronary disease were enrolled at a single tertiary center. Patient data, drug therapy, catheter reports, and ECG recordings were prospectively recorded in a validated electronic archive. The primary outcome measure was death or nonfatal myocardial infarction (MI) over 1 year or until percutaneous or cardiac surgical intervention. Independent prognostic markers were identified using the Cox proportional hazard model.
  
  
  RESULTS
  A total of 682 individuals were recruited of whom 17(2.5%) died or suffered a nonfatal MI in 1 year. In multivariate analysis QRS duration (ms) (HR 1.03 95% CI 1.01-1.05, P = 0.003), extent of coronary disease (HR 2.01 95% CI 1.24-3.58, P = 0.006), and prolonged corrected QT peak interval in lead I (HR 1.02 95% CI 1.00-1.03, P = 0.044) were independently associated with death or nonfatal MI. Receiver-operator characteristic (ROC) analysis for the multivariate model against the primary end point yielded an area under the curve of 0.759 (95% CI 0.660-0.858), P < 0.001.
  
  
  CONCLUSIONS
  QRS duration and QT peak are independently associated with increased risk of death or nonfatal MI in stable patients attending for coronary angiography.
authors.affiliation: Institutions-Royal Preston Hospital, Preston, UK. nadattar@hotmail.com
authors.forename: M Nadeem
authors.initials: MN
authors.lastname: Attar
authors.forename: Kenneth
authors.initials: K
authors.lastname: Wong
authors.forename: David G
authors.initials: DG
authors.lastname: Groves
authors.forename: Nick
authors.initials: N
authors.lastname: Newall
authors.forename: David R
authors.initials: DR
authors.lastname: Ramsdale
authors.forename: Roger K
authors.initials: RK
authors.lastname: Moore
mesh_terms: D000368:Aged; D006328:Cardiac Catheterization / Q000379:methods; D015331:Cohort Studies; D017023:Coronary Angiography; D003327:Coronary Disease / Q000175:diagnosis* / Q000401:mortality* / Q000628:therapy; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000401:mortality* / Q000628:therapy; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D016019:Survival Analysis; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000401:mortality