title: Left Atrial Appendage Occlusion Study (LAAOS): a randomized clinical trial of left atrial appendage occlusion during routine coronary artery bypass graft surgery for long-term stroke prevention.
abstract: BACKGROUND
  Many patients undergoing coronary artery bypass graft (CABG) surgery have risk factors for both atrial fibrillation (AF) and stroke. The left atrial appendage (LAA) is a main source of thrombus coming from the left atrium. LAA occlusion should be tested as a means to reduce future cerebral ischemic events in these patients.
  
  
  METHODS
  The Left Atrial Appendage Occlusion Study (LAAOS) is a randomized clinical trial designed to evaluate the feasibility, safety, and efficacy of LAA occlusion for prevention of ischemic stroke in patients undergoing CABG. The target population consists of patients at risk of AF and stroke who are having routine CABG surgery. The main study will be a prospective, controlled, unblinded trial. Patients at risk of future development of AF, or having AF, will be randomly assigned to undergo or not undergo LAA occlusion. A total of 2500 patients will be randomly assigned and followed for 5 years for the primary outcome of stroke. This study of 2500 patients will have 90% power to detect a relative reduction of 20% in stroke, from a 5-year incidence of 20% in the control group to 16% in the intervention group. Currently, a pilot trial is underway that will enroll 100 patients to assess feasibility, safety, and rates of successful LAA occlusion as assessed by postoperative transesophageal echocardiography. The most suitable surgical technique will also be assessed during the pilot trial. In the pilot study, the main outcomes are safety and rate of successful obliteration of the LAA after surgical occlusion.
  
  
  CONCLUSIONS
  The clinical trial designed to evaluate LAA occlusion at the time of routine CABG surgery is currently in the pilot phase.
authors.affiliation: McMaster University, Hamilton, Ontario, Canada.
authors.forename: Eugene
authors.initials: E
authors.lastname: Crystal
authors.forename: Andre
authors.initials: A
authors.lastname: Lamy
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Connolly
authors.forename: Peter
authors.initials: P
authors.lastname: Kleine
authors.forename: Stefan H
authors.initials: SH
authors.lastname: Hohnloser
authors.forename: Lloyd
authors.initials: L
authors.lastname: Semelhago
authors.forename: Labib
authors.initials: L
authors.lastname: Abouzhar
authors.forename: Irene
authors.initials: I
authors.lastname: Cybulsky
authors.forename: Bernard
authors.initials: B
authors.lastname: Shragge
authors.forename: Kevin
authors.initials: K
authors.lastname: Teoh
authors.forename: Eva
authors.initials: E
authors.lastname: Lonn
authors.forename: Corey
authors.initials: C
authors.lastname: Sawchuk
authors.forename: Feycan
authors.initials: F
authors.lastname: Oezaslan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D020517:Atrial Appendage / Q000601:surgery*; D001281:Atrial Fibrillation / Q000150:complications / Q000188:drug therapy; D001026:Coronary Artery Bypass / Q000009:adverse effects* / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D005500:Follow-Up Studies; D006801:Humans; D008026:Ligation / Q000009:adverse effects / Q000379:methods / Q000592:standards; D008297:Male; D010865:Pilot Projects; D016032:Randomized Controlled Trials as Topic; D012107:Research Design; D020521:Stroke / Q000209:etiology / Q000517:prevention & control*
chemical_list: D005343:Fibrinolytic Agents