title: Non-ST elevation acute coronary syndrome: QRS duration and long-term prognosis.
abstract: BACKGROUND
  Recent studies have demonstrated that QRS duration (QRSd) is associated with poor prognosis in heart failure and ST-elevation myocardial infarction. Less is known about the prognostic importance of QRSd in patients with non-ST elevation acute coronary syndrome (non-ST ACS).
  
  
  OBJECTIVE
  To determine if admission QRSd is associated with 1-year mortality in non-ST ACS.
  
  
  METHODS
  We studied 539 patients (aged 65.52 +/- 12.47 years, 69.9% male) admitted to the coronary unit with non-ST ACS. QRSd was measured on the admission electrocardiogram.
  
  
  RESULTS
  Mean QRSd was 94.29 +/- 18.3 ms. One-year mortality was 13.4%. QRSd showed a good correlation with 1-year mortality and its best cut-off was 92 ms. Patients with QRSd > or = 92 ms were older, more frequently male and with prior history of coronary heart disease. On admission they presented more often in Killip class > 1, and had a higher incidence of heart failure and left ventricular systolic dysfunction. They less often underwent coronary angiography. One-year mortality was higher in patients with QRSd > or = 92 ms. After adjusting for baseline characteristics and treatment, QRSd > or = 92 ms remained an independent predictor of 1-year mortality (adjusted OR=3.87; 95% CI 1.74-8.44).
  
  
  CONCLUSIONS
  In this non-ST ACS population, QRSd was an independent predictor of 1-year mortality after the event.
authors.affiliation: Serviçio de Cardiologia, Hospital de São Marcos, Braga, Portugal. sergia.rocha@hotmail.com
authors.forename: Sérgia
authors.initials: S
authors.lastname: Rocha
authors.forename: Márcia
authors.initials: M
authors.lastname: Torres
authors.forename: Sérgio
authors.initials: S
authors.lastname: Nabais
authors.forename: António
authors.initials: A
authors.lastname: Gaspar
authors.forename: Adília
authors.initials: A
authors.lastname: Rebelo
authors.forename: Sónia
authors.initials: S
authors.lastname: Magalhães
authors.forename: Alberto
authors.initials: A
authors.lastname: Salgado
authors.forename: Pedro
authors.initials: P
authors.lastname: Azevedo
authors.forename: Miguel Alvares
authors.initials: MA
authors.lastname: Pereira
authors.forename: Adelino
authors.initials: A
authors.lastname: Correia
mesh_terms: D054058:Acute Coronary Syndrome / Q000401:mortality* / Q000503:physiopathology*; D000368:Aged; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D011379:Prognosis; D013997:Time Factors