Prophylactic LAA closure during bioprosthetic surgical aortic valve replacement was safe and did not increase bleeding, though the treatment effect on the composite of cardiovascular death, stroke, or systemic embolism changed direction at approximately 7 days.
Key Findings
Results
The primary composite endpoint of cardiovascular death, stroke, or systemic embolism at 30 days occurred numerically less often in the LAA closure group than the control group, but the difference was not statistically significant.
Primary endpoint occurred in 10 of 434 (2.2%) patients in the LAA closure group versus 14 of 452 (3.1%) patients in the control group.
904 patients were included in the modified intention-to-treat analysis (LAA closure n=445; control n=459).
Median age was 73 years (IQR 69–76), 34.8% were women, and 49% had concomitant coronary artery disease.
The trial was investigator-initiated, academic, randomized, open-label, and multicenter (NCT02321137).
Results
The treatment effect of LAA closure on the primary endpoint changed direction at approximately 7 days post-surgery.
In a time-split Cox regression model, the hazard ratio from 0 to 7 days was 2.4 (95% CI, 0.62–9.4; P=0.20), suggesting early harm trend.
From 7 to 30 days, the hazard ratio was 0.29 (95% CI, 0.080–1.0; P=0.056), suggesting a later protective trend.
The directional change at ~7 days indicates a potentially complex early versus late risk-benefit profile.
Results
Prophylactic LAA closure was safe, with no closure-related serious complications and no differences in bleeding between groups.
No closure-related serious complications were observed in the LAA closure group.
There were no statistically significant differences in bleeding events between the LAA closure and control groups.
921 patients were randomized, and 904 were included in the modified intention-to-treat analysis.
Results
Postoperative atrial fibrillation (AF) occurred more frequently in the LAA closure group than the control group, though the difference was not statistically significant.
Postoperative AF occurred in 205 of 445 (46.1%) patients in the closure group versus 184 of 459 (40.1%) in the control group.
Relative risk was 1.1 (95% CI, 0.99–1.3; P=0.07).
AF at discharge occurred in 40 of 445 (9.2%) in the closure group versus 34 of 459 (7.7%) in the control group (RR 1.2, 95% CI, 0.77–1.8; P=0.44).
All enrolled patients had no prior AF at baseline, making postoperative AF a new complication in these subjects.
Methods
The study population consisted of patients without prior AF undergoing bioprosthetic surgical aortic valve replacement, with or without concomitant surgery.
921 patients were randomized across multiple centers in this academic, investigator-initiated trial.
Patients were allocated to prophylactic LAA closure (n=445) or usual care (n=459) in the modified intention-to-treat analysis.
49% of patients had concomitant coronary artery disease, indicating a complex surgical population.
The trial was open-label and multicenter, registered as NCT02321137.
What This Means
This research examines whether surgically closing off a small pouch in the heart called the left atrial appendage (LAA) — during a heart valve replacement surgery — can prevent strokes and other dangerous clot-related events in patients who do not already have atrial fibrillation (an irregular heart rhythm). Nearly 1,000 patients undergoing bioprosthetic aortic valve replacement were randomly assigned to either have this additional LAA closure procedure or receive standard care. The main finding was that the overall rate of serious cardiovascular events (cardiovascular death, stroke, or systemic embolism) within 30 days was slightly lower in the LAA closure group (2.2% vs. 3.1%), but this difference was not statistically significant.
A notable and complex finding was that the benefit or harm of LAA closure appeared to shift over time. In the first week after surgery, there was a trend toward more events in the LAA closure group (though not statistically significant), while after 7 days, there was a trend toward fewer events in that group (also not statistically significant). The procedure appeared safe overall — no serious complications directly related to the LAA closure were observed, and bleeding rates were similar between groups. However, new-onset atrial fibrillation after surgery was numerically more common in the LAA closure group (46.1% vs. 40.1%), though again this difference did not reach statistical significance.
This research suggests that prophylactic LAA closure during aortic valve replacement surgery is feasible and does not appear to cause additional harm in the short term, but whether it meaningfully prevents stroke or cardiovascular events in patients without pre-existing atrial fibrillation remains unclear from this 30-day data. The shifting direction of effect over the first month raises important questions about timing of benefit or risk, and longer-term follow-up data from this trial will be important for drawing firmer conclusions about whether this additional procedure should be routinely offered to patients undergoing this type of heart surgery.
Kiviniemi T, Halfwerk F, Bustamante Munguira J, Zindovic I, Malmberg M, Olsson C, et al.. (2026). Prophylactic Surgical Left Atrial Appendage Closure in Bioprosthetic Aortic Valve Replacement: Short-Term Outcomes of Randomized Controlled LAA-CLOSURE Trial.. Journal of the American Heart Association. https://doi.org/10.1161/JAHA.125.046654