-Original-

Association between Mobility of Residual Left Atrial Thrombus and Stroke Severity in Patients with Nonvalvular Atrial Fibrillation

Yuji Kato¹, Takeshi Hayashi¹, Shintaro Nakano², Takahide Arai², Shinako Fujiwara¹, Kaito Watanabe¹, Kiichiro Oryu¹, Ryutaro Kimura¹, Noriko Arai¹, Toru Nakagami¹, Ichiro Deguchi¹, Shinichi Takahashi¹ and Satoshi Suda¹

¹Department of Neurology and Cerebrovascular Medicine, Saitama Medical University International Medical Center, Saitama, Japan
²Department of Cardiology, Saitama Medical University International Medical Center, Saitama, Japan

Background: The differences in the characteristics of ischemic stroke associated with a mobile versus nonmobile residual left atrial thrombus (LAT) are unclear. We investigated whether the mobility of an LAT detected by transthoracic echocardiography is associated with the clinical features of stroke.
Methods: This study included 20 consecutive patients with nonvalvular atrial fibrillation who were admitted to our hospital for treatment of acute ischemic stroke and then found to have an LAT on transthoracic echocardiography. The patients were divided into two groups: those with a mobile LAT (Group M) and those with a nonmobile LAT (Group N). The clinical, neuroradiological, and echocardiographic variables were assessed.
Results: The LAT was mobile in 11 patients (Group M) and nonmobile in nine patients (Group N). The median National Institutes of Health Stroke Scale score on admission was higher in Group M than N (17 vs. 7, respectively; p=0.196). Four patients in Group M and one in Group N developed in-hospital stroke recurrence (36% vs. 11%, respectively; p=0.319). The prevalence of large vessel occlusion (15 events in Group M and 10 events in Group N, including in-hospital recurrent events) was significantly higher in Group M than N (73% vs. 30%, respectively; p=0.049), which seemed to lead to poorer functional outcomes in Group M than N (ratio of modified Rankin scale score of 0-2 at discharge: 18% vs. 44%, respectively; p=0.336).
Conclusions: The mobility of LAT may affect stroke severity in patients with nonvalvular atrial fibrillation.

J Nippon Med Sch 2024; 91: 322-327

Keywords
cardioembolic stroke, left atrial thrombus, transthoracic echocardiography

Correspondence to
Yuji Kato, MD, PhD, Department of Neurology and Cerebrovascular Medicine, Saitama Medical University International Medical Center, 1397-1 Yamane, Hidaka, Saitama 350-1298, Japan
yujik@saitama-med.ac.jp

Received, October 27, 2023
Accepted, January 10, 2024