Dual layered stents give excellent outcomes for carotid artery stenting, IRON-GUARD-2 study

Tremendous efforts have been made to identify techniques and technologies that can reduce the risk of minor periprocedural stroke with carotid artery stenting (CAS). In the latest issue of JACC: Cardiovascular Interventions, Sirignano et al detail their 1-year follow-up results from the IRONGUARD-2 study using the CGuard-EPS dual-layered stent (DLS) for CAS. This real-world registry has shown that DLS use in clinical practice is safe and associated with minimal occurrence of adverse neurologic events up to 12-month follow-up.

Plaque protrusion through the stent struts has been speculated to cause periprocedural ipsilateral strokes with conventional stents that are being used for CAS. Dual-layered stents (DLS), a new generation of devices, were recently developed to overcome this adverse procedural occurrence, consisting of Nitinol stents combined with a mesh (Nitinol or polyethylene terephthalate) that potentially captures plaque debris and thrombus between the stent and the arterial wall.

The higher metallic coverage afforded by DLSs raised concerns for the potential of both higher rates of restenosis and thrombosis compared with traditional carotid stent designs. With widespread implantation of this novel DLS, is it possible that we might substitute a short-term periprocedural stroke risk for longer-term risks of stent restenosis or thrombosis?

With these key issues in mind, Sirignano et al conducted a physician-initiated, prospective, multispecialty registry enrolled 733 consecutive patients undergoing CAS using the CGuard embolic prevention system.

The primary endpoint was the occurrence of death and stroke at 1 year. Secondary endpoints were 1-year rates of transient ischemic attack, acute myocardial infarction, internal carotid artery (ICA) restenosis, in-stent thrombosis, and external carotid artery occlusion.

The study had a 99% follow-up rate, with 726 of 733 patients completing the 1-year follow-up. Beyond the initial periprocedural 30-day period, there was 1 additional stroke for a cumulative 365-day stroke rate of 0.68%, or 5 of 726 patients. The 12-month restenosis rate was also very low at 0.82%, and only 2 of the 6 patients with restenosis required repeat revascularization.

Since the intensity and duration of antithrombotic medication for DLSs in the carotid artery is controversial, the results from this study have shed some light on this aspect. No predictors of target ICA restenosis and/or occlusion could be detected, and dual-antiplatelet therapy duration (90 days vs 30 days) was not found to be related to major adverse cardiovascular event or restenosis occurrence.

"The persistently low stroke rate (<1%) over the course of 12 months is extremely encouraging, providing evidence now not only for safety, but also for the efficacy of DLSs as a viable therapy for ipsilateral stroke prevention in patients with atherosclerotic carotid stenosis", note Giri et al in an accompanying editorial.

DLS could represent a solution in preventing events related to embolization through stent struts. The IRONGUARD 2 study represents the largest real-world study on patients undergoing CAS with DLS. The use of DLS has proved safe and effective in lowering periprocedural and postprocedural neurologic complications.

These data can be considered hypothesis generating toward the design of a large-scale clinical trial to definitively investigate the long-term safety and efficiency of this endovascular technique of carotid revascularization.

Source: JACC Cardiovascular Interventions:

1. DOI: 10.1016/j.jcin.2021.05.045

2. DOI: 10.1016/j.jcin.2021.06.015