Transition from Transesophageal Echocardiography to Cardiac Computed Tomography for the Evaluation of Left Atrial Appendage Thrombus Prior to Atrial Fibrillation Ablation and Incidence of Cerebrovascular Events During the COVID-19 Pandemic (preprint)

Background: Transesophageal echocardiography (TEE) is variably performed before atrial fibrillation (AF) ablation to evaluate left atrial appendage (LAA) thrombus. We describe our experience with transitioning to the pre-ablation cardiac computed tomography (CT) approach for the assessment of LAA thrombus during the COVID-19 pandemic. Methods We studied consecutive patients undergoing AF ablation at our center. The study cohort was divided into pre- vs. post-COVID groups. The pre-COVID cohort included ablations performed during 1 year before the COVID-19 pandemic; pre-ablation TEE was used routinely to evaluate LAA thrombus in high-risk patients. Post-COVID cohort included ablations performed during the 1 year after the COVID-19 pandemic; pre-ablation CT was performed in all patients, with TEE performed only in patients with LAA thrombus by CT imaging. The demographics, clinical history, imaging, and ablation characteristics, and peri-procedural cerebrovascular events (CVE) were recorded. Results A total of 637 patients (pre-COVID n=424, post-COVID n=213) were studied. The mean age was 65.6  10.1 years in the total cohort, and the majority were men. There was a significant increase in pre-ablation CT imaging from pre to post-COVID cohort (74.8 vs. 93.9%, p=<0.01), with a significant reduction in TEEs (34.6 vs. 3.7%, p=<0.01). One patient in the post-COVID cohort developed CVE following negative pre-ablation CT. However, the incidence of peri-procedural CVE between both cohorts remained statistically unchanged (0 vs. 0.4%, p=0.33). Conclusion Implementation of pre ablation CT-only imaging strategy with selective use of TEE for LAA thrombus evaluation is not associated with increased CVE risk during the COVID- 19 pandemic.

A Randomized Trial of Online Single Session Interventions for Adolescent Depression during COVID-19 (preprint)

The COVID-19 pandemic caused hardship, isolation, and distress, potentially increasing risk for adolescent depression. Even pre-pandemic, <50% of youth with depression accessed care, highlighting needs for accessible interventions. Accordingly, this randomized-controlled trial tested online single-session interventions (SSIs) during COVID-19 in adolescents with elevated depression (N=2,452, ages 13-16). Adolescents from all 50 U.S. states, recruited via social media, were randomized to 1 of 3 SSIs: a behavioural activation SSI, an SSI teaching that traits are malleable, or a supportive control. We tested each SSI’s effects on post-intervention (hopelessness, agency) and 3-month outcomes (depression, hopelessness, agency, generalized anxiety, COVID-related trauma, restrictive eating). Versus the control, both active SSIs reduced 3-month depressive symptoms (ds=0.18); decreased post-intervention and 3-month hopelessness (ds=0.16-0.28); increased post-intervention agency (ds=0.15-0.31); and reduced 3-month restrictive eating (ds=0.12-17). Several differences between active SSIs emerged. Results confirm the utility of free-of-charge, online SSIs for high-symptom adolescents, even in the high-stress COVID-19 context.