Changes in Anticoagulation Treatment and Associated Resolution or Persistence of Left Atrial Thrombus: Insights from LATTEE Registry.

Current guidelines highlight limited evidence on optimal anticoagulation for atrial fibrillation/flutter (AF/AFl) patients with left atrial thrombus (LAT). This study aimed to assess changes in anticoagulation and their association with LAT resolution in AF/AFl patients. Consecutive patients with AF/AFl undergoing transoesophageal echocardiography (TEE) before direct current cardioversion or ablation at 13 cardiology centres were included. Of 3109 patients enrolled, 8.0% (n = 250) had LAT on TEE, with 46% (n = 116) undergoing follow-up TEE, among whom LAT resolved in 55% (n = 64). No statistically significant predictors of LAT resolution were identified. Baseline characteristics were similar across anticoagulation groups, except for higher prevalence of heart failure in dabigatran users. Switching from vitamin K antagonists (VKAs) to non-VKA oral anticoagulants (NOACs) was associated with lower LAT prevalence (15%) compared to remaining on VKA (50%) or switching to low-molecular-weight heparin (75%, p = 0.022). All patients who continued apixaban had persistent LAT at follow-up, while none who switched from apixaban to another NOAC showed LAT (p = 0.033). Other switching strategies showed no statistically significant differences in LAT prevalence during follow-up. In conclusion, LAT resolved in over half of patients who underwent follow-up. LAT resolution may be associated with changes in anticoagulation, but confirmation in randomized trials is needed.