Safety of Cardiac Computed Tomography to Exclude Left Atrial Appendage Thrombus Prior to Direct Current Cardioversion in Patients With Atrial Arrhythmias

Abstract

Cardiac computed tomography (CCT) is a feasible imaging modality to exclude left atrial appendage (LAA) thrombus prior to pulmonary vein isolation procedures but has not been routinely used prior to direct current cardioversion (DCCV) for atrial arrhythmias until piloted during the COVID-19 pandemic. The safety of CCT to exclude LAA thrombus is evaluated in this study. All patients with atrial arrhythmias requiring DCCV as inpatients at Middlemore Hospital between 1 September 2020 to 31 December 2022, and who underwent CCT to exclude LAA thrombus were prospectively collected using the All New Zealand Acute Coronary Syndrome-Quality Improvement (ANZACS-QI) linked cardiac CT registry database. Patients’ clinical records were reviewed for the combined primary outcome of periprocedural and 60-day death, and thromboembolic events including cerebrovascular accidents. A total of 217 patients (64.5% male, mean age 57.8±14 years) underwent CCT during the study period. The majority (37%) were European, 19.8% were Māori, 30.4% were Pasifika, and 7% were other ethnicity. The mean body mass index was 34.8±8 kg/m2. Severe left ventricular systolic dysfunction was present in 70 (32.2%) patients. No LAA thrombus or slow flow was seen in 192 (88.4%) CCT scans. Transoesophageal echocardiography (TOE) was performed in 17 patients with LAA thrombus or slow flow on CCT, of which six had LAA thrombus. Direct current cardioversion was performed in 180 patients with no periprocedural or 60-day stroke. No deaths were recorded. Cardiac CT appears to be a safe alternative to TOE for excluding LAA thrombus prior to DCCV.