Clinical characteristics of stent fracture after sirolimus-eluting stent implantation.

Background: Despite several case reports of sirolimus-eluting stent (SES) fracture and concern regarding restenosis after successful SES implantation, the clinical characteristics of this problem are not well known.

Methods: Clinical records and angiographic films of patients who received follow-up coronary angiography between February 2005 and October 2006 were retrospectively analyzed.

Results: Among the 686 SES implanted in 479 patients, 27 fractures were found in 22 (3.2%) stents in 18 patients. All stent fractures occurred in long stented segments, i.e. >/=28 mm (range, 28 mm to 83 mm). Of the 22 fractured stents, sixteen (72.7%) were identified in the right coronary artery (RCA) and fifteen (68.2%) were found to have a fracture site within 10 mm from areas with increased rigidity due to metal overlap. The significant multivariate predictors of stent fracture were the stented length (Odds ratio 1.06; 95% confidence interval 1.04-1.09; p=0.001) and the RCA location (Odds ratio 4.44; 95% confidence interval 1.66-11.86; p=0.003). The binary restenosis rate was 22.7% and target lesion revascularization was performed in two (9.1%) fractured stents.

Conclusions: SES fracture was associated with a long stented segment, RCA location and metal overlap. Stent fracture may be another potential risk factor for restenosis after successful SES implantation.