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.