Pasqualino Sirignano, MD, (Sapienza University of Rome, Policlinico Umberto, Rome, Italy) opened this morning’s session on innovative concepts in carotid revascularization with a discussion of the 12-month results of the IRONGUARD 2 study.1
Dr. Sirignano shared his thoughts with LINC Today in a Q&A ahead of the session.
Q: The prospective, real world, multicenter IRONGUARD 2 investigates clinical practice of CAS using the CGuard Embolic Prevention system (EPS; InspireMD, Tel Aviv, Israel). Could you describe the present data landscape for dual layer stents such as the CGuard? What does this study add in terms of filling in knowledge gaps?
A: CAS with conventional single layer stents is associated with an increased incidence of post-procedural cerebral events, especially in the very early post-operative period (the so-called plaque healing time), suggesting that the majority of these events seem to be related to embolization through the stent strut.
Dual layer stents, CGuard being one of them, have been available since early 2015. As a new tool in carotid stenting, dual layer stents could represent a solution in preventing events related to embolization through the stent strut thanks to their particular structure, which is able to contain plaque debris, thereby limiting cerebral embolization.
Several small sized studies (and IRONGUARD 1 was one of these2) underlined that this technology could effectively reduce the rate of new neurological events after CAS.
The IRONGUARD 2 study, led by our PI Professor Francesco Speziale, represents the most extensive real world study on patients submitted for CAS with the mesh-covered CGuard EPS. The CGuard EPS has proved safe and effective in lowering peri- and post-procedural neurological complications. Thirty-day follow-up results (0.54% new stroke rate) confirm its role in effectively preventing brain embolic events.1
Early reports on dual layer stent systems suggested that they had issues of acute thrombosis and occlusion. Could you comment on this in light of the real world data from different centers that has emerged since then?
I know very well that acute thrombosis and stent occlusions are still considered a major issue limiting extensive use of dual layer stents, especially in the acute setting.
However, among the 733 patients (20% presenting with symptomatic lesion) enrolled in the IRONGUARD 2 study, we were unable to identify internal carotid artery restenosis or occlusion at 30 days by duplex ultrasound scan.1 In a previous reported series, IRONGURD 1,2 one sudden stent occlusion occurred.
Cumulatively, the IRONGUARD study group observed only one occlusion out of 933 treated patients across the two different studies. Because of that, I would suggest that acute thrombosis and occlusion is not an issue in performing CAS with dual layer stenting, at least using the CGuard micromesh device.
What considerations give rise to the best clinical outcome with minimal post-procedural complications?
My first suggestion is to make a careful selection of the patients to be treated with CAS and the best access route to use. Dual layer stent technology can reduce embolic load during stent release and post-dilatation, and it does; but the aortic arch is a major source of emboli that should be carefully approached. Moreover, the proper use of any kind of cerebral protection device should be considered mandatory. Lastly, all treated patients have to be given dual antiplatelet therapy at least for the first postoperative month.
Where does the CGuard fit into your armamentarium for CAS?
Currently, in Rome where I work under Professor Speziale’s mentorship, CGuard is on the first line of our dedicated armamentarium for CAS. Regardless of the type of embolic protection device used, it represents the first choice of stent. I think this kind of stent could effectively represent the most suitable device in any kind of carotid procedures.
One note of attention: the CGuard, due to its double mesh structure (nitinol plus micromesh), has a larger external diameter than other stents, and therefore it may not be applicable in patients with small vessels requiring access from the arm.
When are the next results expected from the IRONGUARD 2 study?
First of all, I want to thank all the IRONGUARD 2 study collaborators because, despite this difficult time we are currently facing, data collection was concluded perfectly on time.
Our 30-day results published last year were considered as a new landmark for carotid procedures, and we were pushed to analyze our 12-month data also. These data will be presented during this year’s LINC meeting, but it is possible to anticipate that only one new stroke was detected, accounting for a cumulative stroke rate of 0.68%.
Regarding stent restenosis or occlusions, at duplex ultrasound examination these were found in six patients (0.82%): two occlusions left untreated due to unknown time onset, and four asymptomatic in-stent restenoses (two of them, evaluated as >70%, successfully treated by stent-in-stent with a new GGuard EPS). External carotid artery patency was 98.8%.
What would you like to see in future research?
Based on the IRONGUARD experience, CGuard stent deployment should be considered as the first-choice device in all carotid artery stenting procedures, even in cases of high risk composition carotid plaques.
As a future line of research, it could be really stimulating to assess results achievable with CGuard EPS stent in a population of acute patients treated in an urgent/emergent setting.
1. Sirignano P, Stabile E, Mansour W, et al. 1-Month Results From a Prospective Experience on CAS Using CGuard Stent System: The IRONGUARD 2 Study. JACC Cardiovasc Interv. 2020;13(18):2170-2177.
2. Speziale F, Capoccia L, Sirignano P, et al. Thirty-day results from prospective multi-specialty evaluation of carotid artery stenting using the CGuard MicroNet-covered Embolic Prevention System in real-world multicentre clinical practice: the IRON-Guard study. EuroIntervention. 2018;13(14):1714-1720.