CT-Guided Direct Current Cardioversion for Atrial Arrhythmias During the COVID-19 Pandemic

Objective: To assess left atrial appendage (LAA) thrombus detection using a novel cardiac computed tomography (CT) protocol specifically prior to direct current cardioversion (DCCV). Background: Transesophageal echocardiography (TEE) is the gold standard in evaluating the LAA prior to DCCV for atrial fibrillation (AF) or flutter (AFL). The COVID-19 pandemic has restricted availability of TEE and anesthesia support. Methods: Prospective cohort of consecutive patients with uncontrolled AF/AFL referred for DCCV from March 2020 to March 2021 were enrolled. CT evaluation of LAA was performed with an initial arterial and subsequent 30-second delayed acquisition to exclude thrombus prior to DCCV. Primary end points were to assess safety and outcomes. Results: A total of 161 patients were included; mean age 69.8 (11.1) years; mean CHA2DS2-VASc 3.4 (1.7); and HAS-BLED 1.8 (0.9). Median follow-up 175 (105-267) days with zero cardiac-related deaths, and no episodes of TIA or embolic stroke. There was no statistically significant change in mean glomerular filtration rate (GFR) in the study population between the pre- and post-GFR measurements [73.9 (21.0) vs 72.7 (20.3); p=0.104]. Overall mean total dose length product (DLP) was 1042.8 (447.5) mGy*cm. Modifying the CT protocol to a narrower 8-cm axial coverage had a statistically significant decrease in total DLP [from 1130.6 (464.1) mGy*cm to 802.1 (286.4) mGy*cm; P<0.0001]. Conclusion: Cardiac CT is both a safe and feasible alternative imaging to TEE for patients prior to DCCV.