Impact of Sirolimus-Eluting Stent Fracture on 4-Year Clinical Outcomes

Background— Although stent fracture (SF) after sirolimus-eluting stent (SES) implantation has been recognized as one of the predisposing factors of in-stent restenosis, it remains uncertain whether SF can increase the risk of major adverse cardiac events (MACE), especially beyond 1 year after SES implantation. The aim of this study was to assess the impact of SF relative to non-SF on 4-year clinical outcomes after treatment with SES of comparable unselected lesions. Methods and Results— A total of 874 lesions in 793 patients undergoing SES implantation and subsequent angiography 6 to 9 months after index procedure were analyzed. At 6- to 9-month angiographic follow-up, SF was identified in 70 of 874 lesions (8.0%). In-stent late loss was significantly higher in SF lesions versus non-SF lesions (0.42±0.59 mm versus 0.13±0.49 mm, P <0.001), resulting in a significantly higher in-stent restenosis rate (21.4% versus 4.1%, P <0.001). At 4 years, SF versus non-SF was associated with a significantly higher MACE rate (23.2% versus 12.6%, P =0.014), mainly driven by significantly higher target-lesion revascularization (18.8% versus 10.2%, P =0.029) rate. Adverse effects of SF on clinical outcomes occurred mostly within the first year (17.4% versus 6.6%, P =0.001), with similar MACE rate between 1 and 4 years (5.8% versus 5.9%, P =0.611). No significant differences between SF versus non-SF patients were observed in the cumulative frequency of very late stent thrombosis (2.9% versus 1.4%, P =0.281), death (0% versus 2.1%, P =0.252), or myocardial infarction (5.8% versus 2.9%, P =0.165). Conclusions— SF of SES was associated with higher MACE rate up to 1 year, mainly driven by higher target-lesion revascularization, whereas no significant association was evident between years 1 and 4.