Although
drug-eluting stents (DESs) reduce the rates of in-
stent restenosis (ISR) and subsequent target lesion revascularization,
stent fracture (SF) after DES implantation has become an important concern because of its potential association with restenosis and
stent thrombosis. We aimed to assess the pathogenic impact of SF on in-
stent restenotic neointimal tissue components after DES implantation. We analyzed 43 consecutive patients (14 with SF and 29 without SF) with ISR requiring revascularization after DES implantation between January 2008 and March 2014. For evaluation of in-
stent tissue components, integrated backscatter intravascular ultrasound (IB-IVUS) was performed. SF was defined as complete or partial separation of
stent segments observed using plain fluoroscopy or intravascular ultrasound. On volumetric IB-IVUS analyses, patients with SF had a significantly higher percentage of
lipid tissue volume within the
neointima and a significantly lower percentage of fibrous tissue volume than those without (37.3 ± 18.9% versus 24.9 ± 12.4%, P = 0.02, and 61.2 ± 18.3 versus 72.6 ± 12.1%, P = 0.04, respectively). Moreover, SF was positively correlated with the percentage of
lipid volume on multiple linear regression analysis after adjustment for confounding factors (β = 0.36, P = 0.03). The interval from
stent implantation was similar in both groups (47.0 ± 28.7 versus 37.7 ± 33.3 months; P = 0.39). In conclusion, SF is associated with larger
lipid tissue volume within the
neointima after DES placement, suggesting a contribution to the development of neoatherosclerosis and vulnerable
neointima. Thus SF might lead to future adverse coronary events.