title: A large frontal QRS-T angle is a strong predictor of the long-term risk of myocardial infarction and all-cause mortality in the diabetic population.
abstract: BACKGROUND
  A large angle between the QRS vector and the T-wave vector (QRS-T angle) in electrocardiograms (ECGs) has recently been introduced as a marker of poor prognosis. The prognostic value in diabetes is unknown. We assessed the long-term predictive power of the frontal plane QRS-T angle in the diabetic population.
  
  
  METHODS
  In 1992-93, the diabetic population of the municipality of Horsens, Denmark, was delineated by the prescription method, and an age- and gender-stratified sample of 240 diabetic persons was randomly selected. In 2015, 12-lead ECGs taken in 1993-94 were analyzed. Vital statistics were obtained from the Danish Civil Registration System and data regarding hospitalizations taken from The National Patient Registry in July 2015.
  
  
  RESULTS
  In total, 178 people agreed to participate (74%) in the study, with the mean (sd) age being 58.9 (10.2) years and 56% being male. The total observation time was 21.5 (0.18) years, during which time 122 (69%) persons died, 32 (18%) suffered a myocardial infarction (MI) and 126 (71%) reached the composite endpoint of non-fatal MI or all-cause death. In Cox regression multivariate analysis a QRS-T angle above 90° was found to be an independent predictor of all-cause death (HR=2.2 (95% CI: 1.3-3.8)), MI (HR=2.95 (95% CI: 1.1-7.7)) and MI or all-cause death (HR=2.0 (95% CI: 1.2-3.5)) (all p<0.05), when adjusting for the effects of co-variates (gender, age, length of diabetes, BMI, total cholesterol, diabetes type, hemoglobin A1c, smoking, hypertension and previous MI).
  
  
  CONCLUSIONS
  A large QRS-T angle is a strong, independent long-term predictor of all-cause mortality, MI and MI or all-cause death in the diabetic population.
authors.affiliation: Cardiovasc. Res. Unit, Dept. of Med., Regional Hospital West Jutland, Aarhus University, Denmark. Electronic address: ole.may@vest.rm.dk.
authors.forename: Ole
authors.initials: O
authors.lastname: May
authors.affiliation: Cardiovasc. Res. Unit, Dept. of Med., Regional Hospital West Jutland, Aarhus University, Denmark.
authors.forename: Christina Boesgaard
authors.initials: CB
authors.lastname: Graversen
authors.affiliation: Cardiovasc. Res. Unit, Dept. of Med., Regional Hospital West Jutland, Aarhus University, Denmark.
authors.forename: Mia Østergaard
authors.initials: MØ
authors.lastname: Johansen
authors.affiliation: Dept. of Infectious Dis., Aarhus University Hospital, Skejby, Denmark.
authors.forename: Hanne
authors.initials: H
authors.lastname: Arildsen
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D003922:Diabetes Mellitus, Type 1 / Q000150:complications* / Q000401:mortality; D003924:Diabetes Mellitus, Type 2 / Q000150:complications* / Q000401:mortality; D003925:Diabetic Angiopathies / Q000175:diagnosis* / Q000453:epidemiology / Q000401:mortality; D058065:Diabetic Cardiomyopathies / Q000175:diagnosis* / Q000453:epidemiology / Q000401:mortality; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality; D009203:Myocardial Infarction / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology / Q000401:mortality; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012042:Registries; D012307:Risk Factors; D016019:Survival Analysis
keywords: Coronary heart disease; Diabetes complications; Population; Prognosis; QRS-T angle