16-29: Accidental finding of a thrombus formation on a left atrial appendage occluder device during long-term follow-up

Abstract

Introduction: In patients with atrial fibrillation and high bleeding risk, left atrial appendage (LAA) closure is increasingly performed as alternative therapy to oral anticoagulation for stroke prevention. After an initial phase of six weeks to six month of dual anti platelet therapy (DAPT) or oral anticoagulation with subsequent dual antiplatelet therapy, solely aspirin monotherapy is recommended in patients without LAA thrombus and complete seal of the LAA as confirmed by trans-esophageal echocardiography (TEE). In those patients, the need for TEE prior to DC cardioversion is still controversial. We report on a patient, in whom a thrombus on the LAA occluder device was found 21 months after implantation. The case: An 84-year old patient was admitted with recurrent symptomatic common type atrial flutter. CHA2DS2-VASc score and HAS BLED score were 6 and 4, respectively. In January 2014, a percutaneous closure of the LAA with a 33 mm Watchmanwdevice was performed. Periprocedural TEE showed complete sealing of the LAA. The patient was treated with clopidogrel and ASS for six weeks. TEE eleven months after implantation showed complete sealing of the LAA without evidence of LA thrombus (Figure 1). Therefore, DAPT was discontinued. 21 months post device-implantation, he was re-admitted to our hospital for DC cardioversion for symptomatic common type atrial flutter. TEE was performed prior to DC cardioversion to seek for LA thrombi. The LAA was completely sealed, but a sessile thrombus (5x10x15mm) located on the device was found (Figure 2). Consequently, DC cardioversion was not performed. The patient was restarted on oral anticoagulation with a vitamin K antagonist for 6 weeks and rate control with verapamil was performed. The patient is awaiting follow-up TEE. Conclusion: Thrombus formation on a percutaneous LAA closure device may occur during long-term follow up. Therefore, we would strongly recommend TEE prior to DC cardioversion in those patients to seek for LAA thrombi. Figure 1. Transesophageal echocardiographic (TEE) 11 months after Watchman implantation demonstrating complete seal of the left atrial appendage and no thrombus on theWatchman device (Figure Presented).