title: New-onset atrial fibrillation during acute coronary syndromes: predictors and prognosis.
abstract: BACKGROUND
  New-onset atrial fibrillation (AF) frequently complicates myocardial infarction, with an incidence of 6-21%.
  
  
  OBJECTIVE
  To assess the predictors and prognosis of new-onset AF during acute coronary syndromes (ACS).
  
  
  METHODS
  We performed a retrospective observational cohort study including 902 consecutive patients (mean age 64 years, 77.5% male) admitted to a single center over a two-year period, with a six-month follow-up.
  
  
  RESULTS
  AF rhythm was identified in 13.8% patients, of whom 73.3% presented new-onset AF and 26.8% pre-existing AF. New-onset AF was more frequent in older (p<0.001) and hypertensive patients (p=0.001) and in those with previous valvular heart disease (p<0.001) and coronary artery bypass grafting (p=0.049). During hospitalization, patients with new-onset AF more often had respiratory infection (p=0.002) and heart failure (p<0.001), and higher values of NT-proBNP (p=0.007) and peak creatinine (p=0.001). On echocardiography they had greater left atrial (LA) diameter (p<0.001) and more frequent significant mitral regurgitation (p<0.001) and left ventricular ejection fraction (LVEF) ≤40% (p<0.001) and were less likely to have significant coronary lesions (p=0.009) or to have undergone coronary revascularization (p<0.001). In multivariate analysis, age (OR 1.06, p=0.021), LVEF ≤40% (OR 4.91, p=0.002) and LA diameter (OR 1.14, p=0.008) remained independent predictors of new-onset AF. Together with age, diabetes and maximum Killip class, this arrhythmia was an independent predictor of overall mortality (OR 3.11, p=0.032).
  
  
  CONCLUSIONS
  Age, LVEF ≤40% and LA diameter are independent predictors of new-onset AF during ACS. This arrhythmia is associated with higher overall mortality (in-hospital and in follow-up).
authors.affiliation: Serviço de Cardiologia, Hospital de Braga, Braga, Portugal. Electronic address: carlos.galvaobraga@gmail.com.
authors.forename: Carlos
authors.initials: C
authors.lastname: Galvão Braga
authors.affiliation: Serviço de Cardiologia, Hospital de Braga, Braga, Portugal.
authors.forename: Vítor
authors.initials: V
authors.lastname: Ramos
authors.affiliation: Serviço de Cardiologia, Hospital de Braga, Braga, Portugal.
authors.forename: Catarina
authors.initials: C
authors.lastname: Vieira
authors.affiliation: Serviço de Cardiologia, Hospital de Braga, Braga, Portugal.
authors.forename: Juliana
authors.initials: J
authors.lastname: Martins
authors.affiliation: Serviço de Cardiologia, Hospital de Braga, Braga, Portugal.
authors.forename: Sílvia
authors.initials: S
authors.lastname: Ribeiro
authors.affiliation: Serviço de Cardiologia, Hospital de Braga, Braga, Portugal.
authors.forename: António
authors.initials: A
authors.lastname: Gaspar
authors.affiliation: Serviço de Cardiologia, Hospital de Braga, Braga, Portugal.
authors.forename: Alberto
authors.initials: A
authors.lastname: Salgado
authors.affiliation: Serviço de Cardiologia, Hospital de Braga, Braga, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Azevedo
authors.affiliation: Serviço de Cardiologia, Hospital de Braga, Braga, Portugal.
authors.forename: Miguel
authors.initials: M
authors.lastname: Alvares Pereira
authors.affiliation: Serviço de Cardiologia, Hospital de Braga, Braga, Portugal.
authors.forename: Sónia
authors.initials: S
authors.lastname: Magalhães
authors.affiliation: Serviço de Cardiologia, Hospital de Braga, Braga, Portugal.
authors.forename: Adelino
authors.initials: A
authors.lastname: Correia
mesh_terms: D054058:Acute Coronary Syndrome / Q000150:complications*; D000368:Aged; D001281:Atrial Fibrillation / Q000209:etiology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors
keywords: Acute coronary syndrome; Atrial fibrillation; Fatores de risco; Fibrilhação auricular; Prognosis; Prognóstico; Risk factors; Síndrome coronária aguda