HeartRhythm Case Reports | 2019
Left atrial appendage thrombus formation less than 24 hours after empirical cryoballoon-based left atrial appendage isolation: A serious warning
Abstract
Pulmonary vein isolation (PVI) is an effective treatment strategy for patients with paroxysmal atrial fibrillation (AF).1, 2 However, in patients with persistent AF (PersAF) and long-standing PersAF, PVI is associated with limited success rates, often requiring multiple procedures for those not responding to PVI.3 More extensive ablation strategies, including ablation of complex fractionated atrial electrograms, linear lesions, and rotors, have been performed with the aim of improving clinical outcome. However, recent findings remain controversial.4, 5, 6, 7 Therefore, current research is focusing on ablation strategies that potentially enhance procedural success, particularly in nonresponders to PVI. In this context, additional targets outside the PVs have been suggested.8, 9 Di Biase and colleagues8, 10 demonstrated that ectopic beats from the left atrial appendage (LAA) are able to initiate and perpetuate AF, and empirical electrical isolation of the LAA (LAAI) using radiofrequency (RF) current in addition to PVI has been shown to increase clinical success. Although potentially effective, this strategy may cause electromechanical dissociation of the LAA and therefore was assumed to be associated with an increased risk for LAA thrombus formation and subsequent thromboembolic events despite oral anticoagulation.11 However, available data are limited, vary across a wide range, and lack long-term assessments.10, 11, 12 Although data on the thrombogenicity of RF-based LAA isolation are conflicting, no increased risk for LAA thrombus or thromboembolism has been reported after second-generation cryoballoon (CB2, Arctic Front Advance, Medtronic, Minneapolis, MN)–based LAAI.13 Here we report a case of LAA thrombus formation occurring less than 24 hours after CB2-based LAAI despite oral anticoagulation.