Device endothelialization and morphology assessments at 1 year using computed tomography angiography: comparison of traditional with novel puncturable atrial septal defect occluders

Abstract

Background: Complete endothelialization is often not achieved within 6 months after implantation of an atrial septal defect (ASD) occluder, which may lead to microthrombus or thrombosis. This study aimed to assess the endothelialization and morphology of a novel puncturable ASD occluder (ReAces) compared with traditional occluders 1 year post-implantation using computed tomography angiography (CTA).

Methods: Fifteen patients from each group in a randomized controlled trial comparing ReAces with traditional occluders were included at the 1-year follow-up at Zhongshan Hospital, Fudan University. Baseline characteristics and procedural data were recorded. CTA was performed to assess the device morphology and degree of endothelialization. Independent samples t-test and Fisher's exact test were primarily used to compare the above data.

Results: Each patient received a single device and had no residual shunts. There were no differences in defect size (15.3 ± 4.0 mm vs. 15.3 ± 4.7 mm, p = 1.00) or occluder size (21.2 ± 4.4 mm vs. 21.5 ± 5.3 mm, p = 0.882) between the two groups. At the 1-year follow-up CTA, the central region thickness (4.2 mm ± 0.9 mm vs. 7.8 mm ± 2.4 mm, p < 0.0001), left atrial device-occupied volume (1863.3 mm² ± 404.4 mm² vs. 4764.4 mm² ± 2321.2 mm², p < 0.001), and device compression rates (10.1 ± 4.8% vs. 17.5 ± 5.6%, p = 0.001) were significantly lower in the experimental group. All occluders in the experimental group achieved complete endothelialization, whereas in the control group, 7 patients did not (100% vs. 53.3%, p = 0.006).

Conclusions: Compared with traditional occluders, ReAces presented a significantly greater complete endothelialization rate, lower central region thickness, lower left atrial device-occupied volume, and lower device compression rates at 1 year post-implantation by CTA.

Trial registration: Trial registry: ClinicalTrials.gov. Unique identifying number: NCT05371366. Date of registration: 04/05/2022.

Keywords: Atrial septal defect; CTA; Endothelialization; Morphology; Occluder.