In silico Optimization of Left Atrial Appendage Occluder Implantation Using Interactive and Modeling Tools

According to clinical studies, around one third of patients with atrial fibrillation (AF) will suffer a stroke during their lifetime. Between 70 and 90% of these strokes are caused by thrombus formed in the left atrial appendage. In patients with contraindications to oral anticoagulants, a left atrial appendage occluder (LAAO) is often implanted to prevent blood flow entering in the LAA. A limited range of LAAO devices is available, with different designs and sizes. Together with the heterogeneity of LAA morphology, these factors make LAAO success dependent on clinician's experience. A sub-optimal LAAO implantation can generate thrombi outside the device, eventually leading to stroke if not treated. The aim of this study was to develop clinician-friendly tools based on biophysical models to optimize LAAO device therapies. A web-based 3D interactive virtual implantation platform, so-called VIDAA, was created to select the most appropriate LAAO configurations (type of device, size, landing zone) for a given patient-specific LAA morphology. An initial LAAO configuration is proposed in VIDAA, automatically computed from LAA shape features (centreline, diameters). The most promising LAAO settings and LAA geometries were exported from VIDAA to build volumetric meshes and run Computational Fluid Dynamics (CFD) simulations to assess blood flow patterns after implantation. Risk of thrombus formation was estimated from the simulated hemodynamics with an index combining information from blood flow velocity and complexity. The combination of the VIDAA platform with in silico indices allowed to identify the LAAO configurations associated to a lower risk of thrombus formation; device positioning was key to the creation of regions with turbulent flows after implantation. Our results demonstrate the potential for optimizing LAAO therapy settings during pre-implant planning based on modeling tools and contribute to reduce the risk of thrombus formation after treatment.

[1]  G. Lip,et al.  Virchow’s Triad Revisited: Blood Constituents , 2003, Pathophysiology of Haemostasis and Thrombosis.

[2]  Tomoyuki Yambe,et al.  Numerical analysis of hemodynamic changes in the left atrium due to atrial fibrillation. , 2015, Journal of biomechanics.

[3]  K. Kofoed,et al.  A comparative study of different imaging modalities for successful percutaneous left atrial appendage closure , 2017, Open Heart.

[4]  Mathieu Lempereur,et al.  Percutaneous left atrial appendage closure: procedural techniques and outcomes. , 2014, JACC. Cardiovascular interventions.

[5]  J. D. Humphrey,et al.  A haemodynamic predictor of intraluminal thrombus formation in abdominal aortic aneurysms , 2014, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[6]  A. J. Deshmukh,et al.  Device-based Approach to Prevention of Stroke in Atrial Fibrillation , 2015 .

[7]  Lucy T Zhang,et al.  Characterizing left atrial appendage functions in sinus rhythm and atrial fibrillation using computational models. , 2008, Journal of biomechanics.

[8]  Yan Wang,et al.  Left Atrial Appendage Studied by Computed Tomography to Help Planning for Appendage Closure Device Placement , 2010, Journal of cardiovascular electrophysiology.

[9]  Michael Markl,et al.  Left Atrial and Left Atrial Appendage 4D Blood Flow Dynamics in Atrial Fibrillation , 2016, Journal of Cardiovascular Magnetic Resonance.

[10]  Guido Gerig,et al.  User-guided 3D active contour segmentation of anatomical structures: Significantly improved efficiency and reliability , 2006, NeuroImage.

[11]  John Mandrola,et al.  Percutaneous Left Atrial Appendage Closure , 2017 .

[12]  Marta Nuñez-Garcia,et al.  Sensitivity analysis of geometrical parameters to study haemodynamics and thrombus formation in the left atrial appendage , 2018, International journal for numerical methods in biomedical engineering.

[13]  J. Hathcock.  Flow effects on coagulation and thrombosis. , 2006, Arteriosclerosis, thrombosis, and vascular biology.

[14]  Reza Arsanjani,et al.  The left atrial appendage: anatomy, function, and noninvasive evaluation. , 2014, JACC. Cardiovascular imaging.

[15]  Pascal Defaye,et al.  Device-Related Thrombosis After Percutaneous Left Atrial Appendage Occlusion for Atrial Fibrillation. , 2018, Journal of the American College of Cardiology.

[16]  Duong L Le,et al.  Percutaneous methods of left atrial appendage exclusion: an alternative to the internist , 2014, Journal of community hospital internal medicine perspectives.

[17]  Martin Penicka,et al.  A Pilot Study for Left Atrial Appendage Occlusion Guided by 3-Dimensional Rotational Angiography Alone. , 2018, JACC. Cardiovascular interventions.

[18]  Christophe Geuzaine,et al.  Gmsh: A 3‐D finite element mesh generator with built‐in pre‐ and post‐processing facilities , 2009 .

[19]  Tino Ebbers,et al.  Creating hemodynamic atlases of cardiac 4D flow MRI , 2017, Journal of magnetic resonance imaging : JMRI.

[20]  R Duarte,et al.  [Analysis of left ventricular diastolic function using magnetic resonance imaging]. , 2012, Radiologia.

[21]  M. Saric,et al.  Percutaneous Left Atrial Appendage Closure Devices , 2017, Current Cardiovascular Imaging Reports.

[22]  Thomas Song,et al.  Application of 3-Dimensional Computed Tomographic Image Guidance to WATCHMAN Implantation and Impact on Early Operator Learning Curve: Single-Center Experience. , 2016, JACC. Cardiovascular interventions.

[23]  Michael Shenoda,et al.  TCT-377 Use of Direct Oral Anticoagulation Therapy Alone Versus DOAC in Conjunction With Aspirin for Anticoagulation Following Implantation of the Watchman Left Atrial Appendage Closure Device , 2019, Journal of the American College of Cardiology.

[24]  Sanghamitra Mohanty,et al.  Does the left atrial appendage morphology correlate with the risk of stroke in patients with atrial fibrillation? Results from a multicenter study. , 2012, Journal of the American College of Cardiology.

[25]  Inder Singh,et al.  Left Atrial Appendage Closure , 2010, Current cardiology reports.

[26]  Oscar Camara,et al.  Centreline-Based Shape Descriptors of the Left Atrial Appendage in Relation with Thrombus Formation , 2018, STACOM@MICCAI.

[27]  Laurent Younes,et al.  Hemodynamics in the Left Atrium and Its Effect on Ventricular Flow Patterns. , 2015, Journal of biomechanical engineering.

[28]  O. Detante,et al.  Percutaneous left atrial appendage occlusion for stroke prevention in patients with atrial fibrillation and contraindication for anticoagulation. , 2015, Revue neurologique.

[29]  Sergio Berti,et al.  Left atrial appendage occlusion with the AMPLATZER Amulet device: an expert consensus step-by-step approach. , 2016, EuroIntervention : journal of EuroPCR in collaboration with the Working Group on Interventional Cardiology of the European Society of Cardiology.

[30]  T. Ebbers,et al.  Bridging the gap between measurements and modelling: a cardiovascular functional avatar , 2017, Scientific Reports.

[31]  A. Banerjee,et al.  Atrial fibrillation: the current epidemic , 2017, Journal of geriatric cardiology : JGC.

[32]  Tino Ebbers,et al.  Left Atrial 4D Blood Flow Dynamics and Hemostasis following Electrical Cardioversion of Atrial Fibrillation , 2017, Front. Physiol..

[33]  A. Camm,et al.  Left atrial appendage: structure, function, and role in thromboembolism , 1999, Heart.

[34]  Deyuan Zhang,et al.  Left atrial appendage occlusion with lambre in atrial fibrillation: Initial European experience. , 2018, International journal of cardiology.

[35]  Gunnar Seemann,et al.  Functional Imaging and Modeling of the Heart , 2003, Lecture Notes in Computer Science.

[36]  Arturo Evangelista,et al.  Recommendations for the evaluation of left ventricular diastolic function by echocardiography. , 2009, Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography.

[37]  Elliot R. McVeigh,et al.  A Computational Framework for Personalized Blood Flow Analysis in the Human Left Atrium , 2016, Annals of Biomedical Engineering.

[38]  J. Halperin,et al.  Left atrial appendage closure for stroke prevention in atrial fibrillation: state of the art and current challenges , 2007, Nature Clinical Practice Cardiovascular Medicine.

[39]  Hui-Nam Pak,et al.  Why Is Left Atrial Appendage Morphology Related to Strokes? An Analysis of the Flow Velocity and Orifice Size of the Left Atrial Appendage , 2015, Journal of cardiovascular electrophysiology.

[40]  José Ramón López-Mínguez,et al.  Comparison of imaging techniques to assess appendage anatomy and measurements for left atrial appendage closure device selection. , 2014, The Journal of invasive cardiology.

[41]  D. Fatkin,et al.  Relations between left atrial appendage blood flow velocity, spontaneous echocardiographic contrast and thromboembolic risk in vivo. , 1994, Journal of the American College of Cardiology.

[42]  Silvia Schievano,et al.  Computational Fluid Dynamic Analysis of the Left Atrial Appendage to Predict Thrombosis Risk , 2018, fcvm.