Current knowledge on very late stent thrombosis

Abstract

Very late stent thrombosis (VLST) represents a rare, but potentially lethal complication, in the era of percutaneous coronary intervention. Its etiology, pathogenesis, and predictive factors have not yet been established due to its relatively low prevalence and multifactorial nature. In this review article, after presenting the current definitions on stent thrombosis, we focus on the contemporary data on VLST, for both bare-metal stents and drug-eluting stents. Possible pathophysiological mechanisms and predictive factors are also illustrated, with data drawn from several multicenter studies. Factors such as younger patients, smokers at the time of initial DES implantation, STEMI or the presence of thrombus at the time of initial DES implantation, overlapping stents, seem to represent independent predictors of VLST. Finally, there is a special reference on cases of VLST, studied with optical coherence tomography (OCT). OCT managed to identify the cause of VLST in over 97% of the cases in these studies, whereas some of the most common mechanisms of VLST in these patients were stent malapposition, neoatherosclerosis rupture, uncovered struts, and stent underexpansion.