Abstract WP19: Is Direct Oral Anticoagulant More Effective Than Warfarin to Reduce Size of Left Atrial Thrombus in Stroke Patients?

Abstract

Objective: The presence of left atrial thrombus (LAT) in acute stroke patients with nonvalvular atrial fibrillation (NVAF) is the major embolic source for recurrent stroke. The aim of this study was to investigate whether direct oral anticoagulants (DOAC) is more effective than warfarin to reduce the size of LAT detected in acute stroke patients with NVAF. Methods: Among acute stroke patients admitted to five major comprehensive stroke centers from January 2017 to December 2022, acute stroke patients with both AF and LAT detected by transesophageal echocardiography (TEE) were selected, and patients with follow-up evaluation were enrolled. All patients were treated with anticoagulation such as DOAC or warfarin for LAT. Thus, patients were classified into two groups according to the type of anticoagulation; the DOAC group and the warfarin group. We compared the clinical characteristics, the dissolution of LAT, and recurrent stroke within three months after stroke onset evaluated between the two groups. Results: 63 patients (median age 77, male 33 [52%]) were enrolled. DOAC and warfarin groups had 22 (35%) and 41(65%) patients, respectively. Age, gender, NIHSS scores on admission were not different between the two groups. Age was 77 years (IQR, 68-81) in the DOAC group and 76 years (IQR, 68-81) in the warfarin group (P=0.644). 10 men (46%) were in the DOAC group, and 23 (56%) were in the warfarin group (P=0.442). The NIHSS score at admission was 3 (IQR, 1-18) in the DOAC group and 4 (IQR, 2-14) in the warfarin group (P=0.393). Initial LAT size was 0.83 (IQR, 0.41-1.27) cm2 in DOAC and 0.88 (IQR, 0.40-1.56) cm2 in warfarin (p=0.48). On follow-up evaluation (10 [IQR, 7-15] days after initial TEE), the disappearance of LAT was more frequently seen in DOAC group than warfarin group (13/22 [59%] vs. 14/41 [34%], P=0.016). Recurrent stroke within three months after stroke was 1/22 (5%) in DOAC and 3/41 (7%) in warfarin (P=1.000), which was not different. Conclusion: In acute stroke patients with NVAF, DOAC should be more effective than warfarin to dissolve LAT detected by TEE.