Abstract Body (Do not enter title and authors here): The importance of transesophageal echocardiogram (TEE) to exclude left atrial (LA) and left atrial appendage (LAA) thrombus prior to cardioversion for atrial fibrillation (AF) has been debated in patients who are anticoagulated prior to cardioversion. Despite comprehensive anticoagulation protocols, discrepancies in pharmacologic responses due to patient-specific factors such as adherence to anticoagulation, renal function, and genetics suggest that imaging studies may still be critical for patient safety. Although anticoagulation prior to cardioversion is thought to be adequate to prevent thromboembolic disease after cardioversion, there are studies to suggest imaging is always associated with lower incidence of stroke (Palla, et al., 2023). This study evaluates the impact of TEE before cardioversion on stroke reduction in a contemporary cohort of patients with persistent AF, regardless of adequate anticoagulation time.

Question

Do patients with newly diagnosed persistent AF who receive a TEE prior to cardioversion have lower incidence of transient ischemic attack /ischemic stroke compared to those who are anticoagulated for at least four weeks without interruption and cardioverted without thrombus exclusion?

Method

This single-center, retrospective observational study involved 454 patients (>18 years) with newly diagnosed persistent AF undergoing cardioversion. Patients were divided into two groups: those who underwent TEE before cardioversion (n=382) and those who did not receive TEE after a four-week period of uninterrupted anticoagulation. Primary outcomes measured were the incidence of stroke within one-year post-cardioversion. Secondary outcome was mortality.

Results

The incidence of stroke was significantly lower in the TEE group, with a hazard ratio of 0.1358 (95% CI 0.06531-0.2824; p < 0.0001). Mortality rates within a year did not differ significantly between the two groups. There was no significant difference in age, race, CHADS2VASc score, INR, GFR and platelet count between the two groups based on multivariate analysis.

Discussion

TEE prior to cardioversion in patients with newly diagnosed persistent AF significantly reduces the risk of stroke compared to cardioversion after anticoagulation alone. In aligning with the results found in earlier trials such as ACUTE and AFFIRM, this study supports the paradigm that pre-cardioversion imaging to rule out LA/LAA thrombus could be beneficial even amongst patients who have been adequately anticoagulated.