Abstract 12043: Computed Tomography Angiography Assessment of Left Atrial Appendage Post Occluder Device

Abstract

Introduction: Device related thrombosis (DRT) is an indication for continuation of anticoagulation for patients undergoing left atrial appendage (LAA) occlusion. There is a paucity of data in regards to the definition of DRT on coronary CT angiography (CTA) in patients with WATCHMAN FLX TM (Boston scientific) device implantation. Methods: This is a single center experience of using CTA for follow up in patients post WATCHMAN FLX TM implantation. 37 consecutive patients who underwent WATCHMAN FLX TM implantation at our center and had CTA performed at first follow up were included. CTA images were analyzed for the presence of hypo-attenuated thickening (HAT) on the device, device positioning, peridevice gap, angulation, compression percentage, depth of implant from coumadin ridge and enhancement in the LAA compared to left atrium (LA). Results: Among 37 patients with CTA follow up, HAT was noted in 28 patients (75%). 38% of these patients had HAT >3 mm. LAA patency (LAA/LA ratio of >25%) was seen in 7 patients (10%), 4 with gaps around the device and the rest secondary to trans-fabric leak. Gap around the device was noted in 13 patients (35%). 6 of these 13 patients had >4 mm gap; 5/6 patients had HAT and 3/6 patients had >25% enhancement in the LAA compared to LA. Increased compression % on both CTA and intraprocedural TEE was associated with absence of HAT (p=0.0003) as well as better sealing on CTA (LAA/LA ratio of >25%) (p=0.04). 6 months follow up is available on only 18 patients; only one of these patients had stoke and that patient did not have HAT on the CT scan. Conclusions: Definition of thrombus on WATCHMAN FLX TM device is not clearly defined on CTA. HAT on CTA could be artifact from the device knob and gutter or visible endothelialization around the device. Further studies with multimodality imaging and clinical correlation are needed to help determine normal cut offs for HAT on these CTAs.