Left Atrial Appendage Occlusion Debate Revisited

The left atrial appendage (LAA) has been deemed by some to be our “most lethal attachment,” and the concept of excluding it from systemic circulation has been thought to hold great promise. This concept has been around since 1948, when John Madden1 proclaimed it a plausible therapy for recurrent emboli in atrial fibrillation. Despite this, higher-quality evidence in the field is only just emerging.In 2009, we were asked to debate on the topic “Does left atrial appendage occlusion eliminate the need for warfarin?” Dr Holmes represented the protagonist viewpoint,2 while Dr Whitlock represented the antagonist viewpoint.3 The protagonist viewpoint was based on 3 key points to support the position that LAA occlusion can replace warfarin. First, the dominant source of stroke in patients with nonvalvular atrial fibrillation (AF) is cardioemboli, of which >90% are from the LAA.4 Second, oral anticoagulation (OAC) therapy requires long-term use, good control, and ongoing compliance to be effective. Warfarin is underused, is difficult to maintain in therapeutic range, and increases bleeding risk. On the contrary, LAA occlusion is a 1-time procedure that requires no long-term compliance. Third, the imbalance of safety that favored warfarin over the Watchman device in the Watchman LAA Closure Technology for Embolic Protection in Patients With Atrial Fibrillation (PROTECT AF) clinical trial was driven by periprocedural events, which were thought to be decreasing with experience.5 The antagonist viewpoint raised 3 key points to support the position that LAA occlusion could not yet replace warfarin therapy. First, the success and safety of LAA occlusion were as yet incompletely understood. Second, the longer-term protection from stroke related to leaks around occlusion devices had not been shown, and the surgical literature suggests that these leaks may contribute to recurrent events.6 This has important implications for LAA occlusion …