What happened
Concomitant left atrial appendage closure did not significantly reduce stroke or TIA compared to standard care (4.28% vs 5.04%; HR 0.85; 95% CI 0.53-1.37; p=0.517).
LAACS-2 tested whether surgical left atrial appendage closure should be added routinely to planned open-heart surgery, including in patients without prior atrial fibrillation. Over a median 4.0 years it did not significantly reduce stroke or TIA versus standard care (4.28% vs 5.04%; HR 0.85, 95% CI 0.53-1.37; p=0.517). Expert reaction to the earlier LAACS data had been divided; the new readout leaves routine closure unsupported overall, with a signal in patients whose CHA2DS2-VASc was above the median.
Whether the high-CHA2DS2-VASc subgroup signal will hold in LeAAPS and LAA-CLOSURE, and whether longer LAACS-2 follow-up changes the overall null, remains open.
“Our results do not support routine LAA closure in all patients undergoing planned cardiac surgery. However, closure appeared to confer protection in patients at high risk of stroke. As we saw in the LAACS trial, the primary endpoint curves diverged over time in LAACS-2 and follow-up will be continued.”
News Coverage ↗From published coverage, not an answer posted here.
Left atrial appendage occlusion is reasonable but so is not performing it
Original post ↗Volkmar Falk
Endpoint critiqueCardiothoracic surgery director, Charité Medical University BerlinLAACS addresses an important question but does not provide the answer
Original post ↗Routine surgical closure of the left atrial appendage in open heart surgery is advisable
Original post ↗Massimo Baudo
ContextResearcher, Lankenau Institute for Medical ResearchSays more definitive answers await completion of LeAAPS, LAA-CLOSURE, and LAACS-2.
Original post ↗Why the trial, key points, tables, limitations, PICO, abstract, media & sources
Why the trial?
Surgical closure of the left atrial appendage during cardiac surgery may prevent later stroke, but evidence outside patients with known atrial fibrillation is limited. LAACS-2 tested routine concomitant appendage closure at the time of cardiac surgery.
Does concomitant left atrial appendage closure reduce stroke or TIA in patients undergoing first-time planned open-heart surgery?
| Outcome | LAA closure | Open LAA |
|---|---|---|
| Stroke or TIA | 4.28% | 5.04% |
| Primary endpoint · HR 0.85 (95% CI 0.53-1.37); p=0.517 | ||
| Stroke or TIA, CHA2DS2-VASc above median | ||
| Subgroup · 56% relative reduction (p=0.018); per-arm rates not reported; no benefit at lower stroke risk | ||
Representation
Only 4.1% of patients had atrial fibrillation at baseline, so the result mainly addresses patients without an anticoagulation indication.
Subgroup caution
The CHA2DS2-VASc subgroup benefit is hypothesis-generating; per-arm subgroup rates are not reported.
Statistical certainty
The wide CI (0.53–1.37) leaves room for a meaningful overall benefit.
Design limitations
No surgical safety or complication data are reported in the record.
Does concomitant left atrial appendage closure reduce stroke or TIA in patients undergoing first-time planned open-heart surgery?
Expert reaction
ESC Congress 2026
1 expert has reacted so far. We show the split once 3 have.
Expert labels are toward LAACS-2's result, from named public quotes (n=1). As of Aug 31, 2026.
LAACS-2 tested whether surgical left atrial appendage closure should be added routinely to planned open-heart surgery, including in patients without prior atrial fibrillation. Over a median 4.0 years it did not significantly reduce stroke or TIA versus standard care (4.28% vs 5.04%; HR 0.85, 95% CI 0.53-1.37; p=0.517). Expert reaction to the earlier LAACS data had been divided; the new readout leaves routine closure unsupported overall, with a signal in patients whose CHA2DS2-VASc was above the median.
Split on whether LAACS data support routine appendage closure
1 take classified by contention axis so far — the map appears as more land.
Whether the high-CHA2DS2-VASc subgroup signal will hold in LeAAPS and LAA-CLOSURE, and whether longer LAACS-2 follow-up changes the overall null, remains open.
“Our results do not support routine LAA closure in all patients undergoing planned cardiac surgery. However, closure appeared to confer protection in patients at high risk of stroke. As we saw in the LAACS trial, the primary endpoint curves diverged over time in LAACS-2 and follow-up will be continued.”
For surgeons, left atrial appendage occlusion is a reasonable thing to do for patients at high risk of developing atrial fibrillation, but there is not a clear signal one way or the other. It would also be reasonable not to perform it.
Despite tackling an important clinical question, the LAACS study does not deliver a definitive answer on routine surgical appendage closure.
Routine concomitant left atrial appendage closure during first-time open-heart surgery did not significantly reduce the overall risk of stroke or TIA, though a benefit was observed in patients with higher baseline CHA2DS2-VASc scores.
LAACS-2 randomised 1,500 patients undergoing first-time planned open-heart surgery at four sites in Denmark, Spain, and Sweden 1:1 to concomitant left atrial appendage closure or standard care (open LAA). Mean age was 67 years and 18.5% were female. Before surgery, 4.1% had atrial fibrillation, 6.1% prior stroke, and 2.5% prior TIA. Across a median 4.0 years, stroke or TIA occurred in 4.28% versus 5.04% (HR 0.85, 95% CI 0.53 to 1.37; p=0.517). Patients with baseline CHA2DS2-VASc above the median had a 56% reduction in the primary endpoint (p=0.018); those at lower stroke risk did not. Overall mortality did not differ. Source: ESC Congress 2026 press, 31 August 2026.
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Helena Dominguez (2026) conducted an RCT in first-time planned open-heart surgery (n=1,500). Concomitant left atrial appendage closure vs. Standard care (open LAA) was evaluated on stroke or TIA (HR 0.85, 95% CI 0.53-1.37, p=0.517). Concomitant left atrial appendage closure did not significantly reduce stroke or TIA compared to standard care (4.28% vs 5.04%; HR 0.85; 95% CI 0.53-1.37; p=0.517).
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