title: Prognosis following acute coronary syndromes according to prior coronary artery bypass grafting: Meta-analysis.
abstract: OBJECTIVE
  Conduct a meta-analysis to study the prognostic influence of a previous coronary artery bypass grafting (CABG) in patients admitted for an acute coronary syndrome (ACS).
  
  
  METHODS
  A systematic review of the literature was performed using electronic reference databases through January 2013 (MEDLINE, Cochrane Library, Web of Knowledge, Google Scholar and references cited in other studies). Studies in which ACS outcomes with a previous history of CABG were compared with ACS outcomes with no history of previous CABG were considered for inclusion. The main endpoints of interest were mortality and non-fatal acute myocardial infarction. Data was aggregated at three follow-up times using random-effects meta-analysis models.
  
  
  RESULTS
  Twenty-four studies were included which provided 387,181 patients for analysis. Previous CABG ACS patients were older, more diabetic and had a more frequent history of a previous myocardial infarction. Pooled in-hospital mortality was higher for the previous CABG ACS patients (OR 1.22 [1.04-1.44], p<0.01, I(2) 88%). The pooled adjusted OR showed no significant differences for the two groups (adjusted OR 1.13 [0.93-1.37], p=0.22, I(2) 92%). Previous CABG ACS patient had a higher pooled 30-day mortality (OR 1.28 [1.05-1.55], p=0.02, I(2) 74%); a higher non-adjusted (OR 1.61 [1.38-1.88], p<0.01, I(2) 70%) and adjusted (adjusted OR 1.37 [1.15-1.65], p<0.01, I(2) 0%) long-term mortality. Both the in-hospital and the long-term re-infarction rates were higher for the previous CABG ACS patients.
  
  
  CONCLUSIONS
  According to our data, ACS patients with previous CABG history had a higher risk for short- and long-term adverse events.
authors.affiliation: Departamento de Medicina, Serviço de Cardiologia, Hospital Beatriz Ângelo, Loures, Portugal Faculdade de Medicina da Universidade de Coimbra, Coimbra, Portugal rogeriopteixeira@gmail.com.
authors.forename: Rogério
authors.initials: R
authors.lastname: Teixeira
authors.affiliation: Faculdade de Medicina da Universidade de Coimbra, Coimbra, Portugal.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Vieira
authors.affiliation: Departamento de Medicina, Serviço de Cardiologia, Hospital Beatriz Ângelo, Loures, Portugal.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Ribeiro
authors.affiliation: Faculdade de Medicina da Universidade de Coimbra, Coimbra, Portugal Serviço de Cardiologia, Centro Hospitalar e Universitário de Coimbra - Hospital Geral, Coimbra, Portugal.
authors.forename: Lino
authors.initials: L
authors.lastname: Gonçalves
authors.affiliation: Division of Cardiovascular Disease and Internal Medicine, Mayo Clinic, Rochester USA.
authors.forename: Bernard J
authors.initials: BJ
authors.lastname: Gersh
mesh_terms: D054058:Acute Coronary Syndrome / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D001026:Coronary Artery Bypass / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D011379:Prognosis; D012307:Risk Factors
keywords: Acute coronary syndromes; coronary artery bypass grafting; meta-analysis; prognosis