Prevalence and risk factors of pre-procedural left atrial appendage thrombosis in patients undergoing catheter ablation of atrial fibrillation: a retrospective observational study
E Benedik, I KatsoularisAbstract
Background
Atrial fibrillation (AF) is the most common arrhythmia and is associated with an increased risk of systemic embolism, especially ischemic stroke, and heart failure. Embolism is caused by atrial appendage (LAA) thrombosis. To mitigate this risk, anticoagulation therapy is commonly used, while catheter ablation, aiming to pulmonary vein isolation (PVI), is increasingly used to reduce symptoms. Given the increased risk of embolism and stroke during ablation, current guidelines recommend transesophageal echocardiography (TEE) before ablation for the exclusion of LAA thrombosis. However, the evidence supporting these recommendations is limited, particularly in the context of direct oral anticoagulants (DOACs).
Purpose
This study aims to assess the prevalence of pre-procedural LAA thrombosis and identify risk factors that could help determine which patients might be safely spared from screening with TEE.
Methods
We conducted a retrospective analysis of all patients scheduled for PVI at our University Hospital, Sweden, between 2005 and 2024. Baseline characteristics, type of anticoagulant therapy, CHA2DS2-VASc scores, ECG at admission, history of previous PVI and information on pre-procedural TEE findings related to LAA thrombosis were evaluated. Statistical analyses, including univariate and multivariate regressions, were performed to identify predictors of LAA thrombosis and a decision-tree model was created.
Results
In this study 3,453 patients were included. The prevalence of pre-procedural LAA thrombosis was 0.23% (8/3,453 patients). The risk of LAA thrombosis was approximately 18 times higher in patients with CHA2DS2-VASc score ≥ 3 compared to CHA2DS2-VASc < 3 (p=0.007, OR=17.7, 95% CI=2.2-145.0) and approximately 6 times higher in patients treated with vitamin K antagonists compared to DOACs (p=0.026, OR=6.3, 95% CI=1.3-31.4). Atrial fibrillation at admission (compared to sinus rhythm) and history of previous PVI were not significantly associated with increased risk of LAA thrombosis (p = 0.561 and p = 0.141, respectively).
Conclusions
Pre-procedural LAA thrombosis is rare in patients undergoing PVI. Patients with CHA2DS2-VASc score ≥ 3 and those on VKA therapy have a higher risk. These findings suggest that careful patient selection based on clinical risk factors can reduce unnecessary TEE procedures, thereby improving patient comfort while also lowering the risk of complication and reducing healthcare costs.Regression AnalysisDecission Tree