Tahara S， Bezerra HG， Sirbu V， Kyono H， Musumeci G， Rosenthal N， Guagliumi G， Costa MA.
    Harrington McLaughlin Heart and Vascular Institute， University Hospitals Case Medical Centre， Cleveland， OH 44106-5038， USA.
Abstract
    BACKGROUND: A potentially adverse vascular response to overlapping drug eluting stents (DES) has been suggested in current research.
    OBJECTIVE: To evaluate the impact of baseline disease severity at the site of stent overlap.
    METHODS AND RESULTS: This is a substudy of ODESSA， a prospective， randomised controlled trial designed to evaluate healing of overlapping stents. 71/77 patients with a total of 86 overlapping stents were studied: 25 sirolimus， 24 paclitaxel， 26 zotarolimus-eluting stents; and 11 bare metal stents (BMS). Patients were categorised into high-grade stenosis (HGS， ≥ 70% diameter stenosis) and low-grade stenosis (LGS， <70%) at the site of stent overlap. Angiography and intravascular ultrasound were performed after stent deployment and repeated at 6 months， together with additional optical coherence tomography. Images were analysed by an independent core laboratory. End points were binary restenosis， percentage neointimal hyperplasia (%NIH)， mean lumen and stent areas and degree of strut coverage/apposition at overlapping stents at 6 months. Stent overlaps occurred in 49 HGS and 37 LGS. Restenosis was found in 5/6 HGS versus 0/5 LGS treated with overlapping BMS (p=0.01) and 4/43 HGS versus 0/32 LGS treated with overlapping DES. There was a trend towards higher %NIH at BMS overlap in HGS versus LGS (p=0.07). DES overlaps had lower lumen and stent areas and similar %NIH in HGS versus LGS. Any uncovered or malapposed struts occurred more often in overlapping DES at LGS than at HGS (59.4% vs 32.6%， p=0.03).
    CONCLUSIONS: Overlapping DES in normal-appearing coronary segments showed a higher incidence of uncovered or malapposed struts， while restenosis occurred exclusively in overlapping stents at HGS. These findings should be considered when deploying overlapping stents.