CHAMPION-AF

In anticoagulation-eligible patients with nonvalvular atrial fibrillation, left atrial appendage closure with Watchman FLX was noninferior to NOAC therapy for cardiovascular death, stroke, or systemic embolism at 3 years and reduced non-procedure-related bleeding, but ischemic stroke was numerically higher with device therapy.

Study design

  • Prospective, international, randomized trial
  • Open-label design with blinded outcome adjudication
  • 141 sites
  • 1:1 randomization
  • N = 3,000
  • Follow-up: 3 years for primary endpoints

Population

  • Nonvalvular atrial fibrillation
  • Suitable candidates for long-term oral anticoagulation
  • Mean age 71.7 years
  • 31.9% women
  • Mean CHA₂DS₂-VASc 3.5
  • Mean HAS-BLED 1.3
  • Excluded some higher-risk groups, including advanced HF and LVEF <30%

Interventions

  • LAA closure with Watchman FLX: 1,499
  • NOAC therapy: 1,501
  • NOAC selected at clinician discretion
  • Device arm used protocol-directed post-implant antithrombotic therapy

Primary outcome

  • Primary efficacy: cardiovascular death, stroke, or systemic embolism
  • 5.7% with LAA closure vs 4.8% with NOAC
  • Difference 0.9 percentage points; 95% CI -0.8 to 2.6
  • P < 0.001 for noninferiority
  • Primary safety: non-procedure-related major or clinically relevant non-major bleeding
  • 10.9% with LAA closure vs 19.0% with NOAC
  • HR 0.55; 95% CI 0.45-0.67
  • P < 0.001 for superiority
LAA closure vs NOAC
Primary efficacy endpoint at 3 years
6% 4.5% 3% 1.5% 0%
5.7%
LAA closure
4.8%
NOAC
5.7% vs 4.8% | Noninferior
Primary efficacy: cardiovascular death, stroke, or systemic embolism at 3 years.
LAA closure vs NOAC
Primary safety endpoint at 3 years
20% 15% 10% 5% 0%
10.9%
LAA closure
19.0%
NOAC
10.9% vs 19.0% | HR 0.55
Primary safety: non-procedure-related major or clinically relevant non-major bleeding at 3 years.

Secondary outcomes

  • Secondary net clinical benefit favored LAA closure: 15.1% vs 21.8%
  • Procedural + non-procedural major or clinically relevant non-major bleeding: 12.8% vs 19.0%
  • Major bleeding: 5.9% vs 6.4%
  • No difference in cardiovascular death, systemic embolism, or hemorrhagic stroke
  • Ischemic stroke numerically higher with LAA closure: 3.2% vs 2.0%
  • Hemorrhagic stroke: 0.4% vs 0.4%

Safety

  • Non-procedure-related bleeding was lower with LAA closure
  • Periprocedural complication rates were low
  • Procedural success reported at 98.8%
  • Periprocedural stroke: 0.1%
  • Pericardial effusion: 0.6%
  • Procedure-related major bleeding: 0.4%
  • No procedure-related mortality reported
  • Device-related thrombus detected at 4 months in 4.8%

Interpretation

  • CHAMPION-AF supports LAA closure as a potential alternative to NOACs in selected anticoagulation-eligible patients with nonvalvular AF
  • The main advantage was less long-term bleeding
  • The efficacy endpoint met noninferiority, but it was not clearly better than NOAC therapy
  • The ischemic stroke signal with LAA closure is the major caveat
  • Best framed as a shared decision-making option, not a blanket replacement for NOACs
  • Longer-term 5-year follow-up will be important
Doshi, S. K., Kar, S., Nair, D. G., Waggoner, T., Agarwal, H., Moussavian, M., … CHAMPION-AF Investigators. (2026). Left atrial appendage closure or anticoagulation for atrial fibrillation. The New England Journal of Medicine. https://doi.org/10.1056/NEJMoa2517213