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Updated: Nov 5, 2025
The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation
Published on: February 28, 2012
Left Atrial Appendage Occlusion during Cardiac Surgery to Prevent Stroke
Richard P Whitlock1, Emilie P Belley-Cote1, Domenico Paparella1
1From McMaster University (R.P.W., E.P.B.-C., J.S.H., M.S., P.J.D., J.N., K. Balasubramanian, A.L., S.Y., S.J.C.), Hamilton Health Sciences (R.P.W., E.P.B.-C., J.S.H., K. Brady, M.S., P.J.D., J.V., A.L., S.Y., S.J.C.), and the Population Health Research Institute (R.P.W., E.P.B.-C., J.S.H., K. Brady, M.S., P.J.D., J.N., K. Balasubramanian, J.V., A.L., S.Y., S.J.C.), Hamilton, ON, Southlake Regional Health Centre, Newmarket, ON (K.H.T.T.), the University of Toronto and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto (C.D.M.), and Quebec Heart and Lung Institute, Quebec, QC (P.V.) - all in Canada; University of Foggia, Foggia (D.P.), Santa Maria Hospital, Gruppo Villa Maria Care and Research, Bari (D.P.), and the University of Pisa, Pisa (A.C.) - all in Italy; Rhön-Klinikum Campus Bad Neustadt, Bad Neustadt (W.R.), and University Hospital Giessen, Giessen (A.B.) - both in Germany; the Institute for Clinical and Experimental Medicine, Prague (P.B.), and the Center of Cardiovascular Surgery and Transplantation, Brno (P.F.) - both in the Czech Republic; "G. Papanikolaou" Hospital (A.J.B.) and Aristotle University of Thessaloniki (G.I.T.) - both in Thessaloniki, Greece; E. Meshalkin National Medical Research Center, Novosibirsk, Russia (A.B.-P.); the University of Louisville, Louisville, KY (M.S.S.); the University of Melbourne and Royal Melbourne Hospital, Melbourne, VIC, Australia (A.G.R.); Auckland City Hospital, Auckland, New Zealand (S.M.); Amphia Ziekenhuis, Breda (M.A.), and Medical Center Leeuwarden, Leeuwarden (R.J.F.) - both in the Netherlands; the National Heart and Lung Institute, Imperial College London, London (P.P.P.); and the International Research Center, Hospital Alemão Oswaldo Cruz, São Paulo (Á.A.).
Insights
Surgical occlusion of the left atrial appendage during cardiac surgery significantly reduced stroke risk in atrial fibrillation patients. This procedure offers a safer alternative for stroke prevention in this high-risk group.
Area of Science:
- Cardiology
- Neurology
- Vascular Surgery
Background:
- Surgical occlusion of the left atrial appendage is a proposed method to prevent ischemic stroke in patients with atrial fibrillation.
- This procedure can be integrated into existing cardiac surgery for other indications.
Purpose of the Study:
- To evaluate the efficacy and safety of surgical left atrial appendage occlusion in preventing stroke and systemic embolism in patients with atrial fibrillation undergoing cardiac surgery.
- To compare outcomes between patients who underwent left atrial appendage occlusion and those who did not.
Main Methods:
- A multicenter, randomized trial was conducted with patients having atrial fibrillation and a CHA 2 DS 2 -VASc score 2, scheduled for cardiac surgery.
- Participants were randomized to undergo or not undergo left atrial appendage occlusion during surgery, with all receiving standard care including oral anticoagulation.
- The primary outcome was the incidence of ischemic stroke or systemic embolism, with blinded assessment.
Main Results:
- The study included 2379 participants in the occlusion group and 2391 in the no-occlusion group, followed for a mean of 3.8 years.
- Stroke or systemic embolism occurred in 4.8% of the occlusion group versus 7.0% of the no-occlusion group (HR, 0.67; P=0.001).
- No significant differences were observed in perioperative bleeding, heart failure, or death between the groups.
Conclusions:
- Concomitant left atrial appendage occlusion during cardiac surgery in patients with atrial fibrillation significantly lowers the risk of ischemic stroke or systemic embolism.
- The findings support left atrial appendage occlusion as an effective stroke prevention strategy in this patient population, even with ongoing antithrombotic therapy.
Background:
Surgical occlusion of the left atrial appendage has been hypothesized to prevent ischemic stroke in patients with atrial fibrillation, but this has not been proved. The procedure can be performed during cardiac surgery undertaken for other reasons.
Methods:
We conducted a multicenter, randomized trial involving participants with atrial fibrillation and a CHA2DS2-VASc score of at least 2 (on a scale from 0 to 9, with higher scores indicating greater risk of stroke) who were scheduled to undergo cardiac surgery for another indication. The participants were randomly assigned to undergo or not undergo occlusion of the left atrial appendage during surgery; all the participants were expected to receive usual care, including oral anticoagulation, during follow-up. The primary outcome was the occurrence of ischemic stroke (including transient ischemic attack with positive neuroimaging) or systemic embolism. The participants, research personnel, and primary care physicians (other than the surgeons) were unaware of the trial-group assignments.
Results:
The primary analysis population included 2379 participants in the occlusion group and 2391 in the no-occlusion group, with a mean age of 71 years and a mean CHA2DS2-VASc score of 4.2. The participants were followed for a mean of 3.8 years. A total of 92.1% of the participants received the assigned procedure, and at 3 years, 76.8% of the participants continued to receive oral anticoagulation. Stroke or systemic embolism occurred in 114 participants (4.8%) in the occlusion group and in 168 (7.0%) in the no-occlusion group (hazard ratio, 0.67; 95% confidence interval, 0.53 to 0.85; P = 0.001). The incidence of perioperative bleeding, heart failure, or death did not differ significantly between the trial groups.
Conclusions:
Among participants with atrial fibrillation who had undergone cardiac surgery, most of whom continued to receive ongoing antithrombotic therapy, the risk of ischemic stroke or systemic embolism was lower with concomitant left atrial appendage occlusion performed during the surgery than without it. (Funded by the Canadian Institutes of Health Research and others; LAAOS III ClinicalTrials.gov number, NCT01561651.).
