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Left Atrial Appendage Occlusion Study (LAAOS): a randomized clinical trial of left atrial appendage occlusion during
Eugene Crystal1, Andre Lamy, Stuart J Connolly
1McMaster University, Hamilton, Ontario, Canada.
Insights
Left atrial appendage occlusion is being studied to prevent stroke in patients undergoing coronary artery bypass graft surgery. A pilot trial is assessing the feasibility and safety of this procedure for reducing ischemic events.
Area of Science:
- Cardiovascular Surgery
- Neurology
- Clinical Trials
Background:
- Coronary artery bypass graft (CABG) patients often have risk factors for atrial fibrillation (AF) and stroke.
- The left atrial appendage (LAA) is a primary source of thrombus formation in the left atrium.
- LAA occlusion is a potential strategy to mitigate future cerebral ischemic events in high-risk patients.
Purpose of the Study:
- To evaluate the feasibility, safety, and efficacy of LAA occlusion during CABG surgery.
- To determine if LAA occlusion can prevent ischemic stroke in patients at risk for AF and stroke.
- To assess LAA occlusion as a method for reducing cerebral ischemic events.
Main Methods:
- A prospective, controlled, unblinded randomized clinical trial (LAAOS) is planned.
- 2500 patients undergoing CABG will be randomized to LAA occlusion or no occlusion.
- The primary outcome is stroke incidence over 5 years, with 90% power to detect a 20% relative reduction.
Main Results:
- A pilot trial is currently enrolling 100 patients.
- The pilot study assesses feasibility, safety, and successful LAA obliteration via transesophageal echocardiography.
- The optimal surgical technique for LAA occlusion will be determined during the pilot phase.
Conclusions:
- The clinical trial investigating LAA occlusion during CABG is in its pilot phase.
- This research aims to establish LAA occlusion as a preventative measure against stroke in CABG patients.
- Further evaluation is needed to confirm the efficacy of LAA occlusion in reducing stroke risk.
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.
