Endocardial Closure of the Left Atrial Appendage: Established Benefit or Evolving Evidence?

Atrial fibrillation (AF) is a highly relevant arrhythmia in the adult population, frequently occurring in both outpatient and hospital settings. AF can present in paroxysmal, persistent, or permanent forms, and its prevalence is expected to double in the coming decades, driven by population aging, increased comorbidities, and advances in its detection. AF is associated with a higher risk of stroke, systemic thromboembolism, heart failure, cognitive impairment, and mortality. In non-valvular AF, the left atrial appendage (LAA) is the primary site of thrombus formation and the origin of thromboembolic events. Surgical exclusion of the LAA to prevent cardioembolic events dates back to the 1940s, with reports of resection by Madden in 1949.^,

The multicenter LAAOS III study included 4,811 patients with AF and a CHA₂DS₂-VASc score ≥2 undergoing cardiac surgery for another indication; they were randomized to surgical LAA exclusion or control, using four different closure techniques. Most patients remained anticoagulated, reinforcing that LAAOS III evaluated surgical exclusion of the LAA as an additional strategy, not as a substitute for anticoagulation. At the time of the study, the benefit of anticoagulation in preventing stroke in AF had already been established since the late 1980s. After 3.8 years, ischemic stroke or systemic embolism occurred in 4.8% versus 7.0%, respectively (HR 0.67; 95% CI 0.53–0.85; p=0.001), corresponding to a relative reduction of 33%. Thus, current evidence supports surgical exclusion of the LAA as an adjunct strategy to anticoagulation.^,

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