title: Prevention of perioperative thromboembolism in patients with atrial fibrillation.
abstract: BACKGROUND
  The aim of this retrospective study was to review the safety and efficacy of two regimens for the prophylaxis of perioperative thromboembolism in patients with atrial fibrillation.
  
  
  METHODS
  From a database of 14 801 procedures, atrial fibrillation occurred in 1.9 per cent of patients. Those not on oral anticoagulation (n = 146) received low molecular weight heparin (LMWH) before and after surgery (nadroparine 40 units per kg). Patients on oral anticoagulation before surgery (n = 136) received intravenous unfractionated heparin (UFH) after surgery at a dose adequate to maintain the thrombin time at a therapeutic level.
  
  
  RESULTS
  The incidence of perioperative arterial or venous thromboembolism was independent of pre-existing risk factors and occurred in 4.6 per cent of patients, without significant difference between the two regimens (P = 0.780). Logistic regression revealed that thromboembolism was significantly associated with increased perioperative mortality (odds ratio 9.5, (95 per cent confidence interval 2.5 to 35.8); P = 0.001). The rate of postoperative bleeding was 4.8 per cent in patients who had LMWH and 17.6 per cent in those who had UFH (P < 0.001).
  
  
  CONCLUSIONS
  Postoperative anticoagulation with therapeutic UFH in patients with atrial fibrillation was associated with an increased rate of bleeding without reducing the risk of thromboembolism.
authors.affiliation: Department of Visceral and Transplant Surgery, University Hospital Berne, Inselspital, Berne, Switzerland. guido.beldi@insel.ch
authors.forename: G
authors.initials: G
authors.lastname: Beldi
authors.forename: L
authors.initials: L
authors.lastname: Beng
authors.forename: G
authors.initials: G
authors.lastname: Siegel
authors.forename: S
authors.initials: S
authors.lastname: Bisch-Knaden
authors.forename: D
authors.initials: D
authors.lastname: Candinas
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000150:complications*; D016063:Blood Loss, Surgical; D001803:Blood Transfusion; D005260:Female; D006493:Heparin / Q000627:therapeutic use; D006495:Heparin, Low-Molecular-Weight / Q000627:therapeutic use; D006801:Humans; D007431:Intraoperative Complications / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care; D012189:Retrospective Studies; D012307:Risk Factors; D013923:Thromboembolism / Q000517:prevention & control*; D016896:Treatment Outcome
chemical_list: D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight; D006493:Heparin