Page 40 - Journal of Structural Heart Disease Volume 4, Issue 2

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Meeting Abstracts
appendage (LAA). The evaluation of LAA morphologies in haemody- namic terms may shed some light on the role of this structure in the cardiovascular system and the e ect of its occlusion.
Objective: The main objective of this virtual study was to evaluate some haemodynamics parameters in di erent patient-speci c LA/ LAA morphologies to identify characteristics potentially related to a high risk of thrombus formation.
Methods: Eleven patient-speci c morphologies provided by the Cardiovascular Center in Aalst, Belgium were studied. From 3D rotational angiography images, left atria (LA) and LAA geometries were extracted and processed to create volumetric meshes. The Computational Fluid Dynamic (CFD) method was used to simu- late blood ow in the atrium. Simulations were run using a laminar, Newtonian and incompressible ow hypothesis. All walls were simu- lated rigid replicating the worst AF scenario (e.g. chronic AF), when atrial contraction is not possible anymore. At the inlets (pulmonary veins) a time-varying blood ow function was applied following lit- erature data. At the mitral valve a constant pressure of 8 mmHg was imposed during the diastolic phase. In systole, the mitral valve was closed, behaving like a wall.
Results: LAA morphology parameters and indices characterizing blood ow were jointly analysed. For instance, we computed the endothelial cell activation (ECAP) parameter, which is the ratio of the oscillatory shear index (OSI) and the time average wall shear stress (TAWSS), since it estimates the thrombogenic susceptibility of the LA/ LAA walls. In addition, includes the CHA2DS2_VASc score to relate the risk of stroke with the computed haemodynamics and morphological indices. The ECAP distribution in LA during one cardiac cycle in the studied cases shows The higher values of ECAP are located on the LAA.
Conclusion: Despite the limitations of virtual models of biological processes such as thrombogenesis, this study o ers a potential tool to better understand the relation of LAA morphologies and haemo- dynamic parameters.
FATAL LATE ISCHEMIC STROKE ON A POORLY ENDOTHELIALIZED WATCHMAN LEFT ATRIAL APPENDAGE OCCLUSION DEVICE
Graeme Prosperi-Porta, Stephen Wilton, Vikas Kuriachan University of Calgary; Cumming School of Medicine; Libin Cardiovascular Institute of Alberta
History: A 77-year-old female with a signi cant past medical his- tory for immune thrombocytopenic purpura, hypothyroidism, and hypertension was being treated for persistent atrial brillation with a CHA2DS2-VASc score of 3 (points for hypertension, age, and sex). Initially the patient was anticoagulated with warfarin until 2013 when she experienced a left hemorrhagic bursitis with an INR of 2.8. The patient’s anticoagulation was changed to the direct oral anticoagu- lant rivaroxaban until 2015 when this was changed to apixaban fol- lowing a lower gastrointestinal bleed. The patient tolerated this well until April 2016 when a Watchman® left atrial appendage (LAA) occlu- sion device was implanted.
Indication for Intervention: Multiple major bleeding episodes while on anticoagulation.
Intervention: In April 2016 under transesophageal echocardiogra- phy (TEE) guidance a 24mm Watchman® device was implanted into the LAA with adequate positioning and no peri-device leakage. Following the procedure, dual antiplatelet therapy (DAPT) includ- ing aspirin and clopidogrel was initiated. However, in May 2016 she presented to hospital with hemorrhoidal bleeding so her DAPT was changed to warfarin with an INR target of 2.0-3.0. Unfortunately, the INR was subtherapeutic for the rst 5 weeks resulting in a TEE con- rmed thrombus overlying the device in June 2016. After extensive discussion, the INR target was increased to 2.5-3.0 and low dose aspi- rin was initiated. TEE in September 2016 showed thrombus resolu- tion whereby warfarin was discontinued in December 2016. In April 2017, the patient was admitted to the intensive care unit with altered level of consciousness, decompensated septic shock, and hypoxemic respiratory failure with a TEE con rmed device thrombus. Brain MRI showed small acute infarcts involving multiple vascular territories. The patient passed away peacefully in the presence of her family after withdrawing physiologic support. Autopsy showed multiple cere- bral and cerebellar infarcts and micro-infarcts associated with brin thrombi, and cardiac examination showed a poorly endothelialized Watchman® device with a dislodged thrombus in the left atrium. The nal cause of death was determined to be septic shock and multiple thromboembolic events.
Learning Points of the Procedure: We report the late complication of ischemic stroke due to thrombus formation on an incompletely endothelialized Watchman® device 1 year after implantation. This case suggests that the endothelialization process of this device is not fully understood and may be inhibited by early subtherapeutic anticoagulation and thrombus formation. In summary, complete endothelialization is crucial in preventing long-term ischemic stroke, and patients with early anticoagulation or device complications may require additional follow-up to prevent this fatal late complication.
PANNUS FORMATION AFTER LAA OCCLUDER DISLOGEMENT AS A RARE COMPLICATION Alexandr Chasnoits, Oleg Kovalenko, Dmitry Goncharik, Alexander Savchenko, Veronika Barsukevich, Larissa Plaschinskaya, Yulia Persidskikh, Alexander Mrochek Republican Scientific and Practical Center "Cardiology"; Heart Rhythm Department; Minsk City
Pannus formation after laa occluder dislogement as a rare complication
History and Physical: 75 years old female patient was admitted to the hospital in October 2016. Clinical diagnosis: Permanent normosystolic atrial brillation. CTI ablation (2011), VVIR pacemaker implantation (2011), DDDR pacemaker re-implantation (2013), arterial hyperten- sion 2-nd degree, risk 4. Diabetes Mellitus, type 2. Pulmonary hyper- tension. Obesity 2 degree. CHA2DS2-VASc score 5. Patient was taking warfarin and having labile INR.
Imaging and Intervention: Due to high risk of stroke and labile INR on warfarin the patient underwent Left Atrial Appendage Occluder (LAAO) implantation. During the procedure LAA angiography was performed. Entrance of LAA was measured in di erent positions:
Hijazi, Z
2017 LAA CSI Focus Abstracts