From the Guidelines
Computed tomography angiography (CTA) is effective for evaluating left atrial appendage (LAA) closure with the Amulet device, as it provides detailed imaging to assess device positioning and potential complications. CTA allows clinicians to evaluate the complex LAA anatomy and the relationship between the device and surrounding structures, making it a valuable tool for follow-up assessments 1. The use of CTA is supported by a recent study published in the Journal of the American College of Radiology, which highlights the effectiveness of CTA in assessing the left atrium, LAA, and pulmonary venous anatomy 1.
Key Benefits of CTA
- Provides detailed, high-resolution imaging to assess device positioning and potential complications
- Enables comprehensive evaluation of the complex LAA anatomy and the relationship between the device and surrounding structures
- Less invasive than transesophageal echocardiography (TEE), which is the gold standard for immediate post-procedural evaluation
- Can be used as part of a comprehensive follow-up strategy that may include other imaging modalities based on individual patient factors and clinical questions
Considerations for CTA Use
- Involves radiation exposure
- Requires the use of iodinated contrast, which may be contraindicated in patients with significant renal impairment
- A cardiac-gated CTA protocol should be used for optimal assessment, typically performed 1-3 months after implantation and potentially at later intervals depending on clinical concerns 1.
Comparison with Other Imaging Modalities
- CTA is particularly valuable during follow-up assessments, as it is less invasive than TEE and provides detailed imaging to assess device positioning and potential complications
- A prospective study comparing ECG-gated and non–ECG-gated CTA in 62 patients showed significant decrease in dose using the non–ECG-gated protocol, without significant difference in the visual quality of the images, catheter ablation parameters, and AF recurrence rate 1.
Clinical Implications
- CTA should be used as part of a comprehensive follow-up strategy that may include other imaging modalities based on individual patient factors and clinical questions
- The use of CTA can help clinicians to identify potential complications early, reducing the risk of morbidity and mortality, and improving quality of life for patients with LAA closure devices.
From the Research
Effectiveness of CTA in Evaluating Post LAA Closure with Amulet
- CTA is effective in evaluating post LAA closure with Amulet, as it can assess device thrombus, residual leak, positioning, surrounding structures, and pericardial effusion non-invasively 2.
- A study comparing CTA to transoesophageal echocardiography (TEE) found that CTA was more sensitive than TEE for assessing peri-device leak (PDL) and can delineate the cause of residual LAA contrast patency 3.
- A systematic review and meta-analysis found that CTA was associated with a higher likelihood of detecting LAA patency than TEE, with an odds ratio of 2.79 (95% CI 1.34-5.80, p = 0.006) 4.
- CTA can be used as an alternative to TEE for LAA assessment post occlusion, with standardized acquisition and interpretation protocols being developed for clinical practice 4, 5.
- Measurements of LAA dimensions using CTA, TEE, and fluoroscopy have been compared, with CTA providing the largest measurements, followed by TEE and fluoroscopy 6.
Key Findings
- CTA is a feasible alternative to TEE for post-LAA device surveillance 2, 3.
- CTA can detect device thrombus, residual leak, embolization, position, and pericardial effusion 2.
- CTA is more sensitive than TEE for assessing PDL and can delineate the cause of residual LAA contrast patency 3.
- CTA can be used to evaluate LAA closure devices, including Amulet, and assess device positioning, peri-device leak, and device-related thrombus 3, 4.