Serial angiographic and intravascular ultrasound analysis of late stent strut fracture of sirolimus-eluting stents in native coronary arteries

Background Stent fracture in sirolimus-eluting stents (SES) has been reported to be associated with late adverse events. However, a suitable method to diagnose stent fracture is not fully elucidated. Methods One hundred and two consecutive SES implantations were performed in 83 lesions in 56 patients and underwent serial angiography with intravascular ultrasound (IVUS) at baseline and at 6 months follow-up. Angiographic stent strut fracture was defined as stent bending with separation of stent struts. Angiographic hinge movement was defined as stent shaft deviation without separation of stent struts. IVUS stent strut dissociation was defined as the disappearance of stent struts in more than one cross-sectional image which were previously visualized at baseline. Results By angiography, no cases of stent fracture were detected at 6 months. One case of angiographic hinge movement was found at 12 months. However, three instances of stent fracture were detected by IVUS at 6 months. One case of stent fracture showed a patent lumen area at 6 months but subsequently developed late stent restenosis at 12 months. The other two cases were associated with in-stent restenosis at 6 months. Conclusion Compared to angiography, IVUS can more reliably detect stent fracture during follow-up evaluation.