You aren't out of date, Martin. It's the subject that is a bit more complex than it sounds. Yes, a stent does not change a vulnerable plaque into a more stable one. These stents are primarily used to keep arteries open and prevent thrombotic occlusions at the stent location, which might happen there if the narrowed lumen was left unstented. That's how stents reduce the risk of blockages that would otherwise lead to heart attacks. In some individuals, stent locations are also prone to restenosis, which is what your reference might have been about.