Increase in the Size of an Intracardiac Thrombus during Dabigatran Therapy (110 mg b.i.d.) in an Acute Cardioembolic Stroke Patient

Abstract

We report a case of atrial fibrillation in a patient in whom a mobile thrombus in the left atrial appendage increased in size after low-dose dabigatran therapy. A 74-year-old man was admitted to our hospital because of sudden onset of right hemiplasia and dysarthria. On admission, his National Institutes of Health Stroke Scale score was three. Axial diffusion-weighted magnetic resonance images and magnetic resonance angiography images showed hyperintense signals in the left front-parietal cerebral cortex without any intracranial stenotic lesions, and acute cardioembolic stroke associated with nonvalvular atrial fibrillation was diagnosed. Transesophageal echocardiography revealed a mobile thrombosis (1.0 × 2.2 cm) in the left atrial appendage, and dabigatran therapy (110 mg b.i.d.) was initiated to prevent stroke recurrence. Transesophageal echocardiography performed 6 days later revealed that the size of the thrombus had increased to 1.5 × 3.0 cm. Medication was changed to warfarin, and the thrombosis subsequently decreased in size. The patient did not have a recurrent stroke and was discharged with a National Institutes of Health Stroke Scale score of zero. This case demonstrates that low-dose dabigatran may not be effective in reducing the size of a thrombus.

Left atrial thrombus formation and resolution during dabigatran therapy: A Japanese Heart Rhythm Society report

“…Although Dabi appears to be an effective alternative to warfarin in preventing stroke or systemic embolism without requiring PT–INR monitoring, the fact that 4% of patients receiving Dabi still had LA thrombus in our survey suggests that TEE is useful when performed before elective ECV of persistent AF. Thrombus may develop even under Dabi treatment in the presence of mechanical heart valves or rheumatic mitral stenosis [12,13], but a few cases of failure to prevent LA thrombus formation with the use of this agent have also been reported in patients with AF without such backgrounds [14–16]. Although it is hard to prove, we speculate that not only higher CHADS 2 scores, but also the insufficient Dabi dosage given to some of our patients might have led to inadequate anticoagulation and subsequent clot formation.…”

Two-week administration of rivaroxaban resolved left atrial thrombus

“…Vidal and Vanerio [4] reported a case, in whom 6 weeks of dabigatran therapy (300 mg/day) shrunk and resolved left atrial thrombus. We also previously reported that [5] low-dose dabigatran was not sufficient to reduce the size of a left atrial thrombus. In the case, a 6-week treatment with dabigatran (220 mg/day) increased the thrombus size from 10 mm  22 mm to 15 mm  30 mm.…”

Thrombosis of Left Atrial Appendage During Therapy With Direct Oral Anticoagulant. Clinical Case

“…Противоположные результаты показывает случай, описанный Tabata и соавт. [24]: у 74-летнего пациента с неклапанной ФП при ЧПЭхоКГ был обнаружен мобильный тромб (1,0×2,2 см) в ушке ЛП, и начата терапия дабигатраном (110 мг 2 р/сут). Повторная ЧПЭхоКГ через 1 нед выявила, что размеры тромба увеличились до 1,5×3,0 см.…”