CT imaging can visualize leadless pacemakers encapsulated in cardiac tissue, suggest findings published September 11 in JACC: Clinical Electrophysiology.
Researchers led by Jonathan Piccini, MD, from Duke University Medical Center in Durham, NC found that CT can image in vivo leadless pacemaker encapsulation that is common, varies in severity, and can involve multiple anatomical structures.
“CT can identify anatomical features that may complicate retrieval, such as encasement, retrieval feature involvement, myocardial perforation, or valve adherence, and it may help guide end-of-service device management,” Piccini and colleagues wrote.
Leadless pacemakers are growing in popularity for treating bradyarrhythmias. However, the researchers indicated the need to understand the natural history of how these devices interact with the heart’s muscular tissues and how these interactions could affect device management.
Chronic retrieval could help with managing leadless pacemakers, but device encapsulation in surrounding heart tissue is a barrier. And current retrieval data is limited to autopsy and histopathologic analyses.
Piccini and co-authors reviewed CT images from their medical center to evaluate leadless pacemaker encapsulation, device position, and related anatomic features. The study included 69 patients with leadless pacemakers implanted at the medical center who underwent CT after implantation. The team reported an average time of 863 days from implantation to imaging.
CT showed some degree of encapsulation in 50 patients. Another 18 patients had moderate or extensive encapsulation, and two had complete encasement.
The researchers also reported the following findings:
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Encapsulation tissue stemmed from the myocardium (36%) and/or trabeculations/subvalvular apparatus (83%).
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In 16 patients, tissue involved the leadless pacemaker retrieval feature.
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Of 13 patients with serial imaging, CT showed progressive encapsulation in three patients.
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The team observed transmural tine penetration in seven patients and right ventricular free wall implantation in 18 patients.
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CT showed potential anatomic retrieval barriers in 36 patients.
The results highlight CT’s ability to identify potential retrieval challenges, which could inform risk stratification and procedural strategies, the study authors highlighted.
“Future studies are required to understand how encapsulation [and other tissue coverage patterns] identified on CT influence outcomes after leadless pacemaker management procedures such as extraction,” they wrote.
Read the full study here.