Pre ablation imaging modality and ablation characteristics
A total of 517 (81.2%) pre-procedural CT scans were performed (Table
2). Following the implementation of CT-only protocol for LAA thrombus
evaluation, we observed a significant increase in pre-procedural CT scan
from pre-COVID to post-COVID cohorts (74.8 vs. 93.9%,
p=<0.01). In contrast, a significant reduction was observed in
the number of TEEs performed in the pre- to post-COVID groups (34.6 vs.
3.7%, p=<0.01). LA diameter (4.4 ± 0.9 vs. 4.2 ± 0.6 mm,
p=<0.01) and LA volume index [90.9 (74.1-103.1) vs 74.2
(61.9−85.3) mL/m2, p=0.02 ] were significantly higher in the pre-COVID
cohort. A total of 412 (64.7%) patients presented in normal sinus
rhythm (NSR), 178 (21.9%) patients presented in AF, and 39 (6.1%)
patients presented in AFL on the day of ablation.
In the pre-COVID cohort, out of a total number of 147 TEEs, 120 were
performed for presentation in AF, and 24 were performed for presentation
In AFL (Figure 1). While 5 TEEs showed spontaneous echo contrast (SEC),
none of the TEEs showed LAA thrombus, and therefore all the ablations
were carried out as scheduled. In the post-COVID cohort, a total of 8
patients were found to have CT findings concerning for LAA thrombus and
underwent TEE on the same day (Figure 2). TEE excluded the LAA thrombus
in 6 of these patients, and ablation was performed as planned without
any peri-procedural CVE. In 2 patients, TEE confirmed LAA thrombus
leading to the cancellation of the ablation procedure (Figure 3). LAA
thrombus resolved after 8 to 12 weeks of continued anticoagulation in
both of these patients. Apixaban was replaced with warfarin in one
patient, and warfarin therapy was continued in the other patient. Both
patients underwent ablation subsequently.