A Pilot Study for Left Atrial Appendage Occlusion Guided by 3-Dimensional Rotational Angiography Alone

CT-Based Preplanning Allows Abstaining from Intraprocedural TEE during Interventional Closure of the LAA in Patients with Atrial Fibrillation

OBJECTIVES

The aim of this study was to determine whether the application of a CT-based preplanning algorithm might allow abstaining from TEE during LAAC.

BACKGROUND

LAAC is an established treatment alternative for patients with atrial fibrillation. Today, most LAAC procedures are guided by TEE, which, however, leads to the need for patient sedation and might even cause direct harm to the patient. CT-based preplanning of the LAAC procedure, in combination with technical improvements in device design and interventional experience, might allow abstaining from TEE.

METHODS

Fluoro-FLX is a prospective single-center study to evaluate how often TEE leads to a procedural change during interventional LAAC if a dedicated CT planning algorithm is applied. The study hypothesis is that under these circumstances, a sole fluoroscopy-guided LAAC is an alternative to a TEE-guided approach. All procedures are preplanned by cardiac CT and, finally, guided by fluoroscopy only, while TEE is carried out in the background during the intervention for safety reasons.

RESULTS

In none of the 31 consecutive patients did TEE lead to a change in the preplanned fluoroscopy-guided LAAC (success ratio: 1.00; CI: 0.94-1.00), thereby meeting the primary endpoint (performance goal: 0.90). There were no procedure-related adverse cardiac or cerebrovascular events (no pericardial effusion, TIA, stroke, systemic embolism, device embolism, death).

CONCLUSIONS

Our data suggest that it is feasible to perform LAAC under sole fluoroscopic guidance if preplanning is performed using cardiac CT. This might be worth considering, especially in patients who are at high risk for TEE-related adverse events.

Pre-cath Laboratory Planning for Left Atrial Appendage Occlusion - Optional or Essential?

In the wake of rapid advancement in cardiovascular procedural technologies, physician-led preprocedural planning utilizing multi-modality imaging training is increasingly recognized as invaluable for procedural accuracy. Left atrial appendage occlusion (LAAO) is one such procedure in which complications such as device leak, cardiac injury, and device embolization can be decreased substantially with incorporation of physician driven imaging and digital tools. We discuss the benefits of cardiac CT and 3D printing in preprocedural planning for the Heart Team, as well as novel applications by physicians of intraprocedural 3D angiography and dynamic fusion imaging. Furthermore, incorporation of computational modeling and artificial intelligence (AI) may yield promise. For optimal patient-centric procedural success, we advocate for standardized preprocedural imaging planning by physicians within the Heart Team as an essential part of LAAO.

Pre-cath Laboratory Planning for Left Atrial Appendage Occlusion - Optional or Essential?

In the wake of rapid advancement in cardiovascular procedural technologies, physician-led preprocedural planning utilizing multi-modality imaging training is increasingly recognized as invaluable for procedural accuracy. Left atrial appendage occlusion (LAAO) is one such procedure in which complications such as device leak, cardiac injury, and device embolization can be decreased substantially with incorporation of physician driven imaging and digital tools. We discuss the benefits of cardiac CT and 3D printing in preprocedural planning for the Heart Team, as well as novel applications by physicians of intraprocedural 3D angiography and dynamic fusion imaging. Furthermore, incorporation of computational modeling and artificial intelligence (AI) may yield promise. For optimal patient-centric procedural success, we advocate for standardized preprocedural imaging planning by physicians within the Heart Team as an essential part of LAAO.

Usable implantation depth for watchman left atrial appendage occlusion is greater with appendage angiography than transesophageal echocardiography

OBJECTIVES

To compare left atrial appendage (LAA) angiography to transesophageal echocardiography (TEE) for assessing usable LAA depth.

BACKGROUND

TEE is typically employed for procedural measurement of LAA ostial diameter and depth. Since angiography enhances distal LAA anatomy, we sought to compare angiography to TEE for determining usable LAA depth.

METHODS

Seventy five Watchman device cases were retrospectively evaluated. Two independent cardiologists measured intraoperative LAA ostial diameter and depth at standard 0°, 45°, 90°, and 135° TEE omniplane views and in the right anterior oblique (RAO) 30°, caudal (CAUD) 30° angiographic view.

RESULTS

The average age and CHA₂ DS₂ VASc score were 74 (±7.2) years and 4.6 (±1.3), respectively. The average ostial diameter and depth (mm) by TEE were 0°: 19.6 and 26.5; 45°: 17.5 and 26.6; 90°: 18.3 and 25.1; 135°: 19.5 and 23.3. The ostial diameter and depth (mm) by RAO 30° CAUD 30° angiography were 21.1 and 29.7. This angiographic view corresponds to a TEE view between 90° and 135°. In comparison to angiography, TEE 90° underestimated the LAA ostial diameter by 2.9 ± 3.7 mm (P < 0.001) and by 1.9 ± 4.0 mm at TEE 135° (P < 0.01); Pearson's r 0.53 angiography/TEE 90° and 0.50 angiography/TEE 135°. More importantly, TEE 90° underestimated the true usable LAA depth by 5.4 ± 5.8 mm (P < 0.001) and by 7.3 ± 6.1 mm at TEE 135° (P < 0.001); Pearson's r 0.39 angiography/TEE 90° and 0.30 angiography/TEE 135°.

CONCLUSIONS

Compared to TEE, LAA angiography provides additional depth information and may be particularly valuable when patients have insufficient depth for Watchman by TEE measures.

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.