Greyscale intravascular ultrasound and IVUS-radiofrequency tissue characterisation to improve understanding of the mechanisms of coronary stent thrombosis in drug-eluting stents.

Stent thrombosis is one of the major concerns after drug-eluting stent implantation. Multiple mechanical causes (i.e., stent under-expansion, edge dissection, geographic miss, residual stenosis, incomplete stent apposition and aneurysm) have been postulated. These features are easily identifiable by intravascular ultrasound. However, it is uncertain which of them are inextricably related to stent thrombosis, primarily due to the low number of such patients studied by IVUS in case control studies. Complementary to greyscale IVUS, tissue characterisation by IVUS radiofrequency data (RFD) analysis has the potential to add valuable information on the pathogenesis of stent thrombosis by providing information on plaque composition, specifically on the amount of necrotic core and its location (superficial or deep). However, the clinical utility of IVUS-RFD analysis in this context has yet to be demonstrated.