Late Stent Thrombosis After Drug-Eluting Stent

Abstract

Following the inspiration of Dr S. Windecker, the team from Bern, Switzerland, has contributed >30 studies on drug-eluting stent efficacy and safety, several of which represent essential pieces in the puzzle. The article in this issue of Circulation by Cook et al1 belongs to that select group of key references. The series of robust and detailed reports on the Bern-Rotterdam cohort studies have coined the 0.6% yearly linear rate of definite late stent thrombosis associated with the permanent coronary implantation of first-generation drug-eluting stents.2 Intravascular ultrasound imaging of the thrombosed stents has revealed the strong association of incomplete strut apposition with the event.3 At the same time, collective analysis of all the available evidence4 demonstrated that a reduction in restenosis with drug-eluting stents prevented adverse events caused by the treatment of the more frequent recurrences with bare metal stents. With the former compensating for the latter, the net result of this balancing act between safety and efficacy resulted in no difference in death and myocardial infarction rates up to 4 years after the initial procedure. Article see p 391 In the present study, late hypersensitivity reaction was identified as a cause for late stent thrombosis, in association with stent malapposition caused by necrotizing vasculitis around the stent struts. Histopathological analysis of aspirated thrombus showed eosinophilic infiltration typical for type IVb hypersensitivity reaction following implantation of sirolimus-eluting stents. Macrophage infiltration typical for type IVc hypersensitivity was seen with paclitaxel-eluting stents. The biomarker gradient between coronary and peripheral blood was significant for high-sensitivity C-reactive protein and myeloid-related protein 8/14, both markers of local inflammatory reaction. These patterns were not observed with early drug-eluting stent thrombosis, early …