Background: High risk of embolic events exists in both patients with chronic atrial fibrillation (AF) and patients in the perioperative period of ablation (effective treatment for AF). Therefore, anticoagulant therapy is important. Oral anticoagulants can be divided into two major categories: vitamin K antagonists (VKAs) and non-vitamin K antagonist oral anticoagulants (NOACs). VKAs, represented by warfarin, have been widely used as traditional anticoagulants, whereas NOACs have been used in clinical practice, but their anticoagulant effects and side effects are still the focus of research. We used a meta-analysis to compare the incidence of left atrial thrombi (LAT) between different anticoagulants.
Methods: We searched PubMed, EMBASE, Web of Science, and the Cochrane Library databases for observational studies that compared the transesophageal echocardiography (TEE) findings for patients treated with NOACs and VKAs. The incidence of LAT and dense spontaneous echocardiographic contrast (dense SEC) were extracted as the basis of the meta-analysis.
Results: Fifteen studies were included in the meta-analysis. We found that patients anticoagulated with NOACs and VKAs had similar incidence of LAT (OR = 0.74, 95%CI: 0.55-1.00). After excluding the heterogeneous article by sensitivity analysis, we found the incidence of LAT in patients anticoagulated with NOACs is lower than VKAs (OR = 0.59, 95%CI: 0.42-0.84). The results of subgroup analysis showed that the incidence of LAT among three types of NOACs have no significant difference (dabigatran vs. rivaroxaban, OR = 1.16 [0.75, 1.81]; rivaroxaban vs. apixaban, OR = 0.97 [0.54, 1.74]; dabigatran vs. apixaban, OR = 1.09 [0.55, 2.16]).
Conclusion: Patients anticoagulated with NOACs may have lower incidence of LAT than VKAs. The incidence of LAT among different type of NOACs are similar.
Keywords: Anticoagulation; Atrial fibrillation; Left atrial thrombus; Transesophageal echocardiography.