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Updated: Aug 31, 2026
The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation
Published on: February 28, 2012
Leap or lag: left atrial appendage closure and guidelines
1Cardiology Clinical Academic Group, Molecular & Clinical Sciences Institute, St. George's University of London, Cranmer Terrace, London SW17 0RE, UK.
Insights
Left atrial appendage closure (LAAC) offers an alternative to oral anticoagulants (OACs) for patients with atrial fibrillation (AF) at risk of stroke. Guidelines should better reflect clinical practice for patients unable to tolerate OACs.
Area of Science:
- Cardiology
- Medical Devices
- Thrombosis Research
Background:
- Atrial fibrillation (AF) poses a significant risk of thromboembolism, often originating from the left atrial appendage (LAA).
- Oral anticoagulants (OACs) are standard treatment but are contraindicated or poorly tolerated by some patients due to bleeding risks.
- Many patients discontinue or reduce OAC dosage, remaining vulnerable to thromboembolic events.
Purpose of the Study:
- To evaluate left atrial appendage closure (LAAC) as an alternative thromboembolism prevention strategy in AF patients.
- To assess the evidence base for LAAC compared to OACs, considering efficacy and safety.
- To examine the discrepancy between clinical practice and current professional society guidelines regarding LAAC use.
Main Methods:
- Review of clinical trials and observational data on LAAC devices for LAA thrombosis prevention.
- Comparative analysis of LAAC efficacy and safety against OAC therapy.
- Analysis of current professional society guidelines and their alignment with clinical practice.
Main Results:
- LAAC demonstrates comparable therapeutic efficacy to OACs in preventing thromboembolism from the LAA.
- A potential small increase in ischemic strokes may be associated with LAAC compared to OACs.
- Clinical practice often precedes guideline recommendations, especially for patients unsuitable for OACs.
Conclusions:
- LAAC is a viable alternative for AF patients with unacceptable bleeding risks on OACs.
- Guidelines may need stronger recommendations for LAAC in specific patient populations where OACs are not an option.
- The evidence suggests a need for updated guidelines that better reflect clinical realities and patient needs.
Abstract:
Atrial fibrillation (AF) is associated with life-threatening thromboembolism. Most emboli stem from thrombosis in the left atrial appendage (LAA). The current treatment of choice is oral anticoagulants (OACs), but a small proportion of patients cannot take OACs predominantly because of the so-called unacceptable bleeding risks. However, many who initially accept OACs subsequently stop therapy or reduce the OAC treatment to a potentially non-effective dose leaving them exposed to thromboembolic risk. A relatively simple alternative therapy involves the catheter-based insertion of a LAA closure (LAAC) device to prevent thromboembolism from the LAA. There is a considerable evidence base for this therapy consisting of clinical trials and observational data which suggests comparable therapeutic efficacy with a possible small excess of ischaemic strokes. Although LAAC has been very closely examined by regulators and approved for market release, guidelines from most professional societies give only weak recommendations for use of this device which may be the only known effective therapy available to some at-risk AF patients. Guidance materials from the same societies more enthusiastically endorse LAAC. Clinical practice is running well ahead of the guidelines because equipoise has been lost by physicians faced with patients for whom they have no other effective therapy. Guideline writers are correct in providing recommendations which are less strong for LAAC than for OACs, for those who are able and willing to take OAC treatment, but for those who are not, a stronger recommendation is needed. But, should the guidelines lag behind or leap ahead of the available evidence?
