Rapid left atrial appendage thrombus formation before suture ligation with LARIAT

A 74-year-old man with a history of long-lasting persistent atrial fibrillation (AF) on chronic dabigatran treatment (2 × 150 mg/day) was referred for left atrial appendage (LAA) closure following a severe ischemic stroke 2 years before. The patient was at high thromboembolic risk with a CHA2DS2-VASc score of 7 points (1 point for congestive heart failure, age, arterial hypertension, diabetes mellitus, peripheral vascular disease and 2 points for the previous stroke) and HAS-BLED of 3 points (1 point for hypertension, stroke and elderly).
On admission, 2 days before the planned procedure, ECG showed sinus rhythm. Computed tomography confirmed favorable anatomy for epicardial LAA closure (Figure 1 A). Dabigatran was discontinued 3 days before the procedure, and low-molecular-weight heparin was started (2 × 80 mg/day, the last dose on the day of the procedure).
Before starting anesthesia at 3.57 PM the patient was confirmed with no thrombus in LAA by transesophageal echocardiography (TEE) (Figure 1 B). At that time, the patient started to experience AF. Just before starting the LAA epicardial exclusion at 4:27 PM TEE was repeated. Fresh thrombus formation in LAA was observed (Figure 1 C). At 4:31 PM even more solid thrombus was noted (Figure 1 D). The patient was excluded from LAA closure. A high-dose bolus of unfractionated heparin (10,000 U) was given, followed by infusion of 2000 U/h with a hope to resolve the thrombus by the next day. Next day at 10.30 AM another TEE was performed and partial dilution of the thrombus was confirmed (Figure 1 E). No stroke, transient ischemic attack, or embolism was noted. Due to the high risk of thromboembolic events, the patient was discharged home with low-molecular-weight heparin (2 × 80 mg/day) and dabigatran (2 × 150 mg/day). After 2 months, TEE presented no signs of thrombus in the LAA. The patient underwent uncomplicated closed-chested LAA ligation with the LARIAT suture delivery device (SentreHEART, Inc., Redwood City, CA). Complete LAA closure was confirmed with TEE and contrast fluoroscopy. The patient did well after the procedure and was discharged on aspirin (150 mg/day) without any additional oral anticoagulation treatment. A follow-up TEE performed at 3 months revealed a closed LAA with no leaks. After 3 years, the patient was on no anti-platelet or anti-thrombin medications with no signs of recurrent thromboembolic complications.
The LAA is a source of more than 90% of thrombus in AF...


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