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
Abstract
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.