Atrial Thrombosis Prevalence before Cardioversion or Catheter Ablation of Atrial Fibrillation: An Update Systematic Review and Meta-Analysis of Direct Oral Anticoagulants Versus Vitamin K Antagonists

Abstract

Left atrial or left atrial appendage thrombosis (LAT) is contraindication to cardiac ablation (CA) or cardioversion (CV) of atrial fibrillation (AF). This study was aimed to compare the frequency of LAT detected by transesophageal echocardiography (TEE) before CA or CV in AF patients under treatment with direct oral anticoagulants (DOACs) or vitamin K antagonists (VKAs). We searched PubMed, Scopus, Web of Science and Cochran Library databases from inception through July 13, 2023 to select studies reporting data on LAT identification before CA or CV by using TEE in patients with AF treated with DOACs or VKAs. Pooled Odds Ratios (ORs) with 95% confidence interval were calculated with a random effect model. Studies retrieved were 50 (38 observational), 29 on CA, 15 on CV and 6 on both procedures (17096 patients on DOACs and 13666 on VKAs). The overall prevalence of LAT was lower in DOACs than VKAs with an OR of 0.66 (0.52-0.84) confirmed at sensitivity analysis and in most of subgroups. Finding was consistent for the three most reported DOACs: the pooled OR for LAT was 0.68 (0.50-0.90) in Apixaban, 0.67 (0.51-0.88) in Dabigatran, 0.61 (0.43-0.89) in Rivaroxaban, and 1.10 (0.74-1.64) in Edoxaban (not significant). In conclusion, in this large meta-analysis on AF patients, the prevalence of LAT by TEE evaluation performed before CV or CA appears lower in those treated with DOACs than VKAs. Additional research may help in better understanding differences among these classes of anticoagulant drugs in the setting of protection against AF-related left atrial thrombotic formation.