Features of Left Atrial Appendage Thrombosis in Patients With Persistent Nonvalvular Atrial Fibrillation After COVID-19.

Aim      To evaluate the incidence and characteristic features of left atrial appendage (LAA) thrombosis in patients with persistent nonvalvular atrial fibrillation (AF) after COVID-19.Material and methods  Transesophageal echocardiography (TEE) was performed for 469 patients (57.4 % males; mean age, 64.0 [58.0; 70.0] years) with persistent nonvalvular AF before scheduled sinus rhythm restoration. In 131 of these patients (27.9 %), the most recent episode of arrhythmia developed during the coronavirus infection. The time from the onset of COVID-19 to TEE was 145 [62; 303] days. All patients received an adequate anticoagulant therapy, in most cases, with direct oral anticoagulants for at least 3 weeks preceding the study.Results A LAA thrombus was detected in 20 (5.9 %) patients who have had no coronavirus infection and in 19 (14.5 %) patients after COVID-19 (р=0.0045). 18 of 19 (94.7 %) thrombi found in patients who have had COVID-19 were mural whereas only 5 (25.0 %) of such thrombi were found in patients who have had no COVID-19 (p<0.0001). In the absence of LAA thrombus, the LAA emptying velocity was 32.0 [25.0; 40.0] cm/sec whereas in the presence of a mural thrombus, it was 25.0 [20.0; 32.3] cm/sec, and in the presence of a typical thrombus, it was 17.0 [13.5; 20.0] cm/sec (р<0.0001). A Kaplan-Meier analysis showed that the median time of mural thrombus dissolution was 35.0 (95 % confidence interval (CI), 24.0-55.0) days and for a typical thrombus, this time was 69.0 (95 % CI, 41.0-180.0) days (р=0.0018).Conclusion      Patients with persistent AF who have had COVID-19 had LAA thrombosis 2,5 times more frequently and, in most cases, the thrombus was mural. Mural thrombi, in contrast to typical, are not associated with a pronounced decrease in LAA emptying velocity and dissolve twice as fast as typical thrombi with an adequate anticoagulant treatment.

The left atrial appendage thrombosis of in patients with persistent atrial fibrillation after the novel coronavirus infection.

Aim      To evaluate the incidence and features of left atrial appendage (LAA) thrombosis in patients with persistent atrial fibrillation (AF) after novel coronavirus infection (COVID-19).Material and methods  Percutaneous echocardiography (pcEchoCG) was performed for 128 patients with persistent AF prepared for cardioversion, 36 (28.1 %) of whom had had COVID-19. In 3 (8.3 %) patients, the lung lesion area was 50-75 %; in 31 (86.1 %) patients, 25-50 %; in 1 (2.8 %) patient, less than 25 %. One patient had no lung lesion. Median time from the onset of COVID-19 to the patient enrollment in the study was 76.5 days. At the time of enrollment, the polymerase chain reaction test for SARS-CoV-2 was negative in all patients.Results Patients after COVID-19 and those who had not had COVID-19 were comparable by age (62.5±9.2 and 62.4±9.1 years, respectively; р=0.956), gender (men 52.8 and 59.8 %, respectively; р=0.471), and risk of stroke (score 2.19±1.28 and score 1.95±1.35, respectively; р=0.350). Duration of the last arrhythmia episode was longer for patients after COVID-19 than for the comparison group (76.5 and 45.0 days, respectively; р=0.011). All patients received oral anticoagulants. 55.6 % of COVID-19 patients received rivaroxaban, whereas 62.0% of patients who had not had COVID-19 were treated with apixaban. Median duration of the anticoagulant treatment was longer for COVID-19 patients than for the comparison group (61.5 and 32.0 days; р=0.051). LAA thrombus was detected in 7 (19.4 %) patients after COVID-19 and in 6 (6.5 %) patients of the comparison group (р=0.030). In COVID-19 patients, the thrombus adhered to LAA wall over the entire thrombus length whereas in patients who had not have COVID-19, the thrombus had a free part that formed a sharp angle with LAA walls. In the presence of LAA thrombus, the LAA blood flow velocity was considerably higher for COVID-19 patients than for the comparison group (31.0±8.9 and 18.8±4.9 cm/sec, respectively; p=0.010). At the follow-up examination performed at 24.0 days on the average, the thrombus was found to be dissolved in 80 and 50% of patients after and without COVID-19, respectively (р=0.343).Conclusion      In patients with persistent AF after the novel coronavirus infection, LAA thrombosis was detected more frequently than in patients who had never had COVID-19; it was characterized by mural localization and was not associated with a decrease in LAA blood flow velocity.