title: Anticoagulation therapy in atrial fibrillation in combination with acute myocardial infarction influences long-term outcome: a prospective cohort study from the Register of Information and Knowledge About Swedish Heart Intensive Care Admissions (RIKS-HIA).
abstract: BACKGROUND
  The American and European guidelines do not agree with regard to antithrombotic treatment in patients with atrial fibrillation (AF) and acute myocardial infarction (AMI), thus causing uncertainty among physicians. We investigated the prescription of oral anticoagulation (OAC) in patients discharged alive with AF after an AMI and the influence of OAC treatment on 1-year mortality.
  
  
  RESULTS
  This was a prospective cohort study using data from the Register of Information and Knowledge about Swedish Heart Intensive care Admissions (RIKS-HIA) on patients admitted to the coronary care units of 72 Swedish hospitals from 1995 to 2002. A total of 6182 patients discharged alive with first registry-recorded AMI and AF on discharge ECG were included. One-year mortality data were obtained from the Swedish National Cause of Death Register. Only 30% (n=1848) of the 6182 patients with AF were prescribed OAC. At 1 year, the unadjusted mortality was 31% (1183 deaths) in the platelet-inhibitors only group and 22% (414 deaths) in the OAC-treated group. In Cox regression analysis with adjustment for confounding factors, OAC treatment was associated with a reduction in 1-year mortality (relative risk 0.73; 95% CI 0.62 to 0.86; P<0.001) in hospital survivors of AMI with AF. The reduction in mortality appeared to be caused primarily by a lower rate of ischemic heart death (55.6% versus 62.0%) and fatal stroke (5.7% versus 7.5%) in the OAC group. This reduction of mortality was similar among most subgroups based on age, sex, baseline characteristics, previous disease manifestations, and medications.
  
  
  CONCLUSIONS
  In daily clinical practice, OAC was only given to a minority (30%) of AMI patients with AF, despite the fact that OAC was associated with a 29% relative and 7% absolute reduction in 1-year mortality after adjustment for confounding variables. The results emphasize the importance of OAC treatment for AF after AMI.
authors.affiliation: Department of Cardiology, University Hospital of Linköping, Sweden. stenestrand@riks-hia.se
authors.forename: Ulf
authors.initials: U
authors.lastname: Stenestrand
authors.forename: Johan
authors.initials: J
authors.lastname: Lindbäck
authors.forename: Lars
authors.initials: L
authors.lastname: Wallentin
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage*; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000209:etiology / Q000401:mortality*; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000401:mortality*; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage; D011379:Prognosis; D011446:Prospective Studies; D012042:Registries; D012307:Risk Factors; D015996:Survival Rate; D013548:Sweden / Q000453:epidemiology; D013927:Thrombosis / Q000401:mortality / Q000517:prevention & control*; D016896:Treatment Outcome
chemical_list: D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors