From the Guidelines
A successful left atrial appendage (LAA) closure with an Amulet device is indicated when there is no significant flow around the device into the LAA, even if contrast passes through the device but not clearly around it. The Amulet device is designed with a porous structure that allows some contrast to pass through the fabric of the device itself, which is normal and expected, as noted in the context of percutaneous LAA occlusion recommendations 1. What's important is that there is no significant leakage around the edges of the device (peri-device leak), which would indicate incomplete closure. Key considerations include:
- The device's design and its implications for contrast passage
- The importance of assessing for peri-device leaks
- The role of follow-up imaging to confirm proper positioning and effective closure. Clinicians typically look for leaks greater than 3-5mm as potentially concerning, as these might allow thrombus formation and embolization, highlighting the need for careful evaluation post-procedure. The ultimate goal of LAA closure is to prevent thrombus formation in the appendage and subsequent stroke risk, so minor contrast permeation through the device fabric doesn't compromise this goal as long as the device is well-seated and there's no significant flow around it, aligning with recommendations for percutaneous LAA occlusion in patients with atrial fibrillation and contraindications for long-term anticoagulant treatment 1. Follow-up imaging at 45-60 days post-procedure with transesophageal echocardiography (TEE) or cardiac CT is often performed to confirm proper positioning and effective closure.
From the Research
Definition of Successful Left Atrial Appendage Closure
The success of left atrial appendage closure (LAAC) with the Amulet device is determined by the absence of significant peri-device leak (PDL) after the procedure.
Peri-Device Leak Detection
PDL is typically detected using transesophageal echocardiography (TEE) or cardiac computed tomography angiogram (CCTA) 2. The presence of contrast within the left atrial appendage on these imaging modalities indicates a PDL.
Criteria for Successful Closure
If contrast is passed around the device but not clearly within the device, it may indicate a successful closure. However, the definition of successful closure varies among studies. Some studies consider a closure successful if there is no or minimal PDL, while others define success based on the absence of thromboembolic events or major adverse cardiac events (MACE) during follow-up.
Studies on LAAC with Amulet Device
A study on the Amulet device reported a high rate of successful closure, with a PDL rate of 56.7% at 12-month follow-up 2. Another study on the use of the Amulet device for peri-device leak after Watchman device implantation reported successful closure with complete sealing of the left atrial appendage 3.
Key Factors for Successful Closure
Procedure planning and careful assessment of left atrial appendage anatomy are crucial for minimizing the risk of PDL or device-related thrombosis 3. A device compression ratio of less than 10% has been associated with a higher incidence of PDL 2.
Clinical Implications
The clinical significance of PDL after LAAC is still debated. Some studies have reported a higher incidence of MACE in patients with PDL, while others have found no significant difference in outcomes between patients with and without PDL 2, 4. Further studies are needed to determine the clinical importance of PDL and the criteria for successful LAAC.
- Key points to consider:
- Successful LAAC is defined by the absence of significant PDL.
- PDL detection is typically performed using TEE or CCTA.
- Procedure planning and careful assessment of LAA anatomy are crucial for successful closure.
- The clinical significance of PDL is still debated, with some studies reporting a higher incidence of MACE in patients with PDL 2, 4.