Despite advances in medical therapy, stroke remains a major complication in patients with atrial fibrillation. Until the publication of recent studies, percutaneous left atrial appendage occlusion had been considered potentially more beneficial than anticoagulation. However, the recent publication of CLOSURE-AF in the NEJM has challenged these findings for devices such as Watchman®, showing significant inferiority compared with medical therapy with DOACs.

Isolated surgical occlusion, in contrast, has been less extensively investigated because of its more invasive nature. However, in patients with atrial fibrillation who require sternotomy for another indication, concomitant occlusion becomes an attractive option with little additional risk. Nevertheless, the role of these procedures in patients without atrial fibrillation remains uncertain. In this context, the authors review the available evidence and discuss whether this intervention should be extended beyond patients with atrial fibrillation.

As we know, the current management of atrial fibrillation is based on anticoagulation in patients at high embolic risk (CHA2DS2-VA >2 points). Even so, approximately 15% of stroke admissions occur in patients with atrial fibrillation. In addition, we know that the effectiveness of anticoagulants in preventing stroke depends on regular long-term use, and in clinical practice this is limited by underprescription, poor adherence, and the resulting non-compliance. In this setting, there is growing interest in non-pharmacological strategies that may reduce stroke risk independently of treatment adherence. For this reason, in this review, the authors examine the role of left atrial appendage occlusion in patients without atrial fibrillation as a preventive strategy against stroke.

This article is a review based on the available evidence regarding left atrial appendage occlusion, including randomized studies such as LAAOS III, with clearly beneficial results that have been incorporated into clinical guidelines, and more recent studies such as ATLAS, LAACS, and OPINION, as well as observational studies by Gerçek et al., Chikwe et al., and McCarthy et al. Across these studies, potential benefits appear to be present, although none has yet conclusively demonstrated a clear impact of left atrial appendage occlusion in patients without atrial fibrillation.

The LAAOS III trial, a pragmatic randomized study of left atrial appendage occlusion in patients with atrial fibrillation undergoing cardiac surgery, showed a 33% reduction in ischaemic stroke or systemic embolism. It was the first high-quality study to demonstrate this benefit and has been incorporated into current clinical practice guidelines.

Observational studies by Gerçek et al., Chikwe et al., and McCarthy et al. suggest a reduction in stroke risk among patients without atrial fibrillation undergoing left atrial appendage occlusion during cardiac surgery, with particularly favourable findings in those who develop postoperative atrial fibrillation or receive associated anticoagulation. However, these findings should be interpreted cautiously because of the inherent limitations of their study design.

Regarding the most recent clinical trials, studies such as ATLAS have shown the safety of the procedure, with a trend towards fewer events, whereas LAACS demonstrated a significant reduction in neurological events, although mainly in patients with atrial fibrillation. In contrast, OPINION, which was conducted in patients without atrial fibrillation, did not show significant differences in event rates, leaving the role of this strategy in this population unresolved.

In this context, the effectiveness of left atrial appendage occlusion for stroke prevention in patients without atrial fibrillation remains an open question. The Left Atrial Appendage Exclusion for Prophylactic Stroke Reduction Trial (LeAAP) has been designed to provide definitive evidence on this issue.

This review clearly reinforces the benefits and indication of left atrial appendage occlusion in patients with atrial fibrillation undergoing cardiac surgery. This technique should be systematically incorporated into our clinical practice, particularly as several surgical techniques and novel devices are available to perform it with low additional risk.

COMMENTARY:

After all the arguments outlined above, one question remains: should this become a systematic strategy in all patients undergoing cardiac surgery, regardless of the presence of atrial fibrillation? This issue arises because its benefit has not yet been demonstrated in this subgroup of patients, although observational studies suggest that it may reduce complications, particularly in those who develop de novo postoperative atrial fibrillation.

This question is currently being assessed in ongoing clinical trials, and their results should help clarify whether left atrial appendage occlusion may have a broader preventive role in cardiac surgery. For now, we can only wait and see whether future evidence confirms this potential change in our clinical practice.

REFERENCE:

Fournier R, Belley-Côté EP, Xu J, Whitlock RP. Left Atrial Appendage Occlusion During Cardiac Surgery; Should the Indications Expand? Eur J Cardiothorac Surg. 2026 Feb 5;68(2):ezaf484. doi: 10.1093/ejcts/ezaf484.