Do drug elution components increase the risk of fracture of sirolimus-eluting stents?

Objectives: Stent fracture (SF) of sirolimus-eluting stents (SES) has emerged recently in the literature and shown to be associated with an increased risk of restenosis; however, little is known regarding SF after bare-metal stent implantation. We sought to assess whether the use of SES was associated with an increased risk of SF compared with its bare-metal platform, the Bx-velocity stent (BX-BMS). Methods: A total of 478 lesions in 416 patients undergoing SES implantation and subsequent angiography 6-9 months after the index procedure were compared with 152 lesions in 142 consecutive patients treated with BX-BMS. Stented lesions with total stent-length greater than 40 mm were excluded. Results: There were no significant differences in overall baseline clinical and anatomic features between the SES and BX-BMS groups, or in SF frequencies at 6-9 month follow-up (4.4% for SES and 1.3% for BX-BMS, P=0.078). In-stent restenosis was observed more often in SF lesions versus non-SF lesions (34.8 vs. 7.7%, P<0.001) in association with a higher 3-year adverse events rate (27.3 vs. 13.6%, P=0.076). The risk of SF at 6-9 months was independently associated with total stent length [odds ratio (OR), 2.13; 95% confidence interval (CI), 1.18-3.83; P=0.012], angulated lesions (OR, 4.25; 95% CI, 1.80-10.00; P=0.001), and right coronary artery lesions (OR, 3.55; 95% CI, 1.46-8.62; P=0.005) but not with SES use. Conclusion: Stent implantation in right coronary artery lesions, tortuous lesions, and/or longer lesions covered with longer stents, and not SES versus BX-BMS use, may be associated with increased likelihood of SF.