Significant association of coronary stent fracture with in-stent restenosis in sirolimus-eluting stents

BACKGROUND: Several reports have suggested that stent fractures in sirolimus-eluting stents (SESs) might be related to in-stent restenosis (ISR). However, the role of stent strut fracture in ISR has not been clearly elucidated. Therefore, we investigated the association of the SES fracture and ISR. METHODS: From 2003 to 2006, SES implantations with follow-up coronary angiography (CAG) for 628 lesions in 557 patients were analyzed. We reviewed clinical and procedural factors that might affect SES fracture and ISR. The median time interval from stent implantation to follow-up CAG was 9 months (range: 2-30 months). RESULTS: ISR occurred in 38 patients (5.7%), and 21 stent fractures (3.3%) were identified by follow-up CAG. Fourteen cases occurred in the left anterior descending artery, and seven occurred in the right coronary artery. The binary ISR rate in the stent fracture group was higher compared with that of the nonfracture group (38.1% vs. 4.6%, P<0.001). Predictors of ISR as estimated by multivariate analysis were a stent diameter less than 2.75 mm [odds ratio (OR)=2.76, P=0.012], a stent length over 28 mm (OR=3.30, P=0.024), and stent fracture (OR=11.03, P<0.001) after controlling for the angiographic and clinical risk factors of ISR. CONCLUSION: Stent fracture was an independent predictor of ISR and may be one of the crucial mechanisms of ISR after implantation of an SES.