Abstract 2156: In-Stent Restenosis after Sirolimus-Eluting Stent Implantation is Related to Coronary Stent Fracture

Background and objectives : It has been reported in few studies about relationship between sirolimus-eluting stent (SES) fracture and in-stent restenosis (ISR). Therefore, authors investigated clinical characteristics of the SES fracture and the association with ISR. Subjects and Methods : From December 2003 to February 2006, implantation and follow-up coronary angiography(CAG) for 796 sirolimus-eluting stents were carried out in Severance hospital. We reviewed clinical, procedural and structural factors which might affect SES fracture and ISR. Results : Twenty four fractures after 796 SES implantation were identified by follow-up coronary angiography, sixteen cases in the left anterior descending artery and eight in the right coronary artery. The median time interval from stent implantation to follow up CAG was 9.0 months [range: 2 ~ 30 months]. No statistical difference was found in stent diameter (fracture group 3.06 ± 0.32 mm vs non-fracture group 3.08 ± 0.31 mm, P=0.778). Length of fractured stents was longer than non-fractured stents (30.29 ± 4.16 mm vs 24.51 ± 6.18 mm, P<0.001). The binary ISR rate in the stent fracture group was higher compared to non-fracture group (50% vs 4.4%, p < 0.001). Predictors for ISR estimated by multivariate analysis were stent fracture (OR=33.6, p < 0.001), stent diameter less than 3.0 mm (OR=2.84, p =0.015) and stent length over 28 mm (OR = 3.10, p = 0.023). Among twelve cases which had both binary restenosis and stent fracture, eight cases were treated by balloon angioplasty or additional stent implantation considering the condition of patients. Conclusion : Stent fracture may be one of the crucial mechanisms of ISR after implantation of SES. However, further studies in larger scale are required to define the incidence, predisposing factors, and clinical outcomes of SES fracture.