The CHAMPION-AF trial randomized 3,000 patients with nonvalvular atrial fibrillation (AFib) (mean age, 72 years; mean CHA₂DS₂-VASc score, 3.5; mean HAS-BLED score, 1.3) who were suitable for long-term oral anticoagulation to either left atrial appendage closure (LAAC) (Watchman Flx, Boston Scientific) or non–vitamin K antagonist oral anticoagulants (NOACs).¹

At three-year follow-up, the primary efficacy endpoint of cardiovascular death, stroke, or systemic embolism was noninferior between groups (5.7% LAAC vs. 4.8% NOAC, p<0.001 for noninferiority), the primary safety endpoint of nonprocedural bleeding events was significantly lower in the LAAC group (19.0% NOAC vs. 10.9% LAAC, p<0.001 for superiority), and the secondary net clinical benefit endpoint (combined efficacy and safety endpoints) favored the LAAC group (21.8% NOAC vs. 15.1% LAAC, p<0.001 for noninferiority).

The authors acknowledge that these findings may not be generalizable to all patients because certain populations were excluded from the trial, including those with advanced heart failure and LVEF <30%.

Although the trial results were encouraging for LAAC as a first-line alternative to NOAC, additional concerns remain regarding its adoption into clinical practice.

First, there was an unexpectedly higher but not statistically significant rate of ischemic strokes in the LAAC group (3.2% LAAC vs. 2.0% NOAC) and surprisingly no difference in the occurrence of hemorrhagic strokes between groups (0.4% LAAC vs. 0.4% NOAC). Second, nearly one-half of the patients in both groups underwent AFib ablation and the ability for a successful AFib ablation to obviate the need for long-term anticoagulation, recently explored by the OCEAN trial,² is an area of ongoing research. Last, the recently published CLOSURE-AF trial³ revealed contradictory results from the CHAMPION-AF trial, and more investigation is needed to understand if this divergence is due to differences in the study population, LAAC considerations, or trial design.

The pending five-year follow-up study of the CHAMPION-AF trial hopefully will shed some light on these unanswered questions.

References

1. Doshi SK, Kar S, Nair DG, et al. Left atrial appendage closure or anticoagulation for atrial fibrillation. N Engl J Med. Published online March 28, 2026. doi:10.1056/NEJMoa2517213
2. Verma A, Birnie DH, Jiang C, et al. Antithrombotic therapy after successful catheter ablation for atrial fibrillation. N Engl J Med. 2026;394(4):323-332. doi:10.1056/NEJMoa2509688
3. Landmesser U, Skurk C, Kirchhof P, et al. Left atrial appendage closure or medical therapy in atrial fibrillation. N Engl J Med. 2026;394(13):1270-1280. doi:10.1056/NEJMoa2513310