CHAMPION-AF: LAA Closure Non-Inferior to OAC for AF Outcomes

The management of non-valvular atrial fibrillation (NVAF) necessitates strategies to mitigate stroke risk, primarily through antithrombotic therapy. However, the long-term use of oral anticoagulants (OACs) is associated with an increased risk of bleeding, posing a clinical dilemma for patients, particularly those with a high bleeding risk. Left atrial appendage closure (LAAC) has emerged as an alternative intervention, aiming to reduce thrombotic events by excluding the left atrial appendage, a common site for thrombus formation in AF. The question of whether LAAC can provide comparable safety and efficacy to OAC without the same bleeding burden has been a focus of ongoing research.

The CHAMPION-AF and Related Trials

The CHAMPION-AF trial, reported from ACC.26, evaluated outcomes in patients with atrial fibrillation randomized to receive LAAC or oral anticoagulation. While the specific results of CHAMPION-AF are not detailed in the provided abstracts, related trials and registries offer insight into the broader context of antithrombotic therapy post-LAAC. The NAPT-LAAC trial (Non-Antithrombotic Versus Single antiPlatelet Therapy Following Left Atrial Appendage Closure) is a prospective, randomized, controlled, open-label, blinded-endpoint multicentre study designed to assess antithrombotic regimens after LAAC.^1,2,3

The NAPT-LAAC trial aims to determine if non-antithrombotic therapy is non-inferior to aspirin monotherapy after 45 days of OAC monotherapy following LAAC.^1,2,3 This trial includes patients with NVAF and a CHA2DS2-VA score of ≥2 who successfully undergo LAAC.^1,2,3 A total of 500 patients will be randomized (1:1) to either aspirin monotherapy or non-antithrombotic therapy for the 45 days following OAC monotherapy.^1,2,3 The primary outcome is a composite of all-cause mortality, myocardial infarction, stroke, systemic embolism, major bleeding, and clinically relevant non-fatal bleeding during a maximum of 4 years of follow-up.^1,2,3 Major bleeding or clinically relevant non-fatal bleeding is defined as Type 2, 3, or 5 bleeding, according to the Bleeding Academic Research Consortium definition.^1,2,3

The TERMINATOR Registry also contributes to understanding antithrombotic therapy post-LAAC, although its specific findings regarding comparative efficacy are not detailed in the provided abstracts.³ The consistent rationale across these studies highlights a clinical need to clarify whether long-term antiplatelet therapy is truly required after LAAC, especially given that LAAC is often considered for patients at high risk of bleeding.^1,2,3 The NAPT-LAAC trial specifically addresses the probable non-inferiority of long-term non-antithrombotic therapy to aspirin monotherapy in this patient population.^1,2,3

The provided abstracts for NAPT-LAAC, while identical, outline a clear methodology for assessing post-LAAC antithrombotic strategies. The CHAMPION-AF trial, by randomizing patients to LAAC or OAC, directly compares these two primary approaches for stroke prevention in AF. The implication from the title, suggesting primary results from ACC.26, is that LAAC has demonstrated non-inferiority to OAC in a comprehensive assessment of thrombotic and bleeding outcomes. The detailed results of CHAMPION-AF, particularly the hazard ratios and p-values for the composite endpoints, would provide the quantitative evidence supporting this conclusion. The NAPT-LAAC trial, by focusing on post-LAAC antithrombotic regimens, addresses a subsequent but related clinical question, aiming to optimize therapy for patients who have already undergone the procedure.