Prevalence and Clinical Correlates of Spontaneous Echo Contrast in Patients on Oral Anticoagulation Undergoing Catheter Ablation for Atrial Fibrillation

Background: Spontaneous echo contrast (SEC) in the left atrial appendage (LAA) is associated with an increased risk of cerebral embolism in patients with atrial fibrillation (AF). Novel oral anticoagulants (NOACs) are increasingly prescribed as first-line therapy and have shown a comparable benefit-risk ratio compared to vitamin K antagonists (VKAs). The aim of this study was to investigate whether NOACs decrease the incidence of SEC compared to VKA. Methods: We retrospectively analysed 542 patients who underwent transoesophageal echocardiography (TEE) prior to AF ablation at our institution. SEC was characterised by dynamic, smoke-like echoes within the LA cavity or LAA on TEE. Results: SEC was detected in 58 patients (10.7%) and occurred significantly more often in patients on VKA (n = 39; 13.6%) compared to patients on NOACs (n = 19, 7.5%; p = 0.02). Decreased left ventricular function (p < 0.001), arterial hypertension (p < 0.001), LA enlargement (p < 0.001) and AF during TEE (p < 0.001) were significantly more often observed in patients showing SEC. Transient ischemic attack or stroke did not occur in any patient during AF ablation. Conclusion: The incidence of SEC on TEE in patients prior to AF ablation was significantly lower in patients treated with NOACs as compared to patients treated with VKA. Patients with multiple risk factors showed a higher SEC incidence. The results support the recommendation of NOACs as firstline oral anticoagulation in non-valvular AF.