Late drug-eluting stent thrombosis: importance of intravascular ultrasound

We report two cases of late occurring drug-eluting stent thrombosis (ST) where coronary angiography failed to identify the cause but intravascular ultrasound (IVUS) revealed underlying mechanical problems with the initial stent deployment. Mechanical factors such as stent underexpansion and residual edge stenoses may be more important in the pathogenesis of late drug-eluting ST than previously recognized. Intravascular ultrasound is required to reliably detect these problems and optimize subsequent reintervention.