CHAMPION-AF and left atrial appendage closure: non-inferiority or a trade-off in risk?

The Watchman FLX versus Novel Oral Anticoagulation for Embolic Protection in the Management of Patients with Non-Valvular Atrial Fibrillation (CHAMPION-AF) trial compared left atrial appendage (LAA) closure using the Watchman FLX device with non-vitamin K antagonist oral anticoagulants (NOACs) in patients with non-valvular atrial fibrillation eligible for long-term anticoagulation. LAA closure demonstrated non-inferiority for the composite endpoint of cardiovascular death, stroke, or systemic embolism and reduced non-procedure-related bleeding. However, interpretation is limited by a permissive non-inferiority margin, reliance on a composite endpoint, exclusion of procedural bleeding from the primary safety outcome, and a numerical excess of ischaemic strokes. Overall, CHAMPION-AF represents a shift in risk profile rather than therapeutic equivalence, supporting LAA closure in selected patients rather than as a routine first-line alternative to NOAC therapy.