Metal allergy to everolimus-eluting cobalt chromium stents confirmed by positive skin testing as a cause of recurrent multivessel in-stent restenosis

The goal of this work is to quantitatively assess the relationship between the reported restenosis rates and stent induced arterial stress or strain parameters through finite element method. The impact of three stent designs (Palmaz–Schatz stent, Express stent, and Multilink Vision stent) on the arterial stress distributions were characterized. The influences of initial stent deployment location, stent-tissue friction, and plaque properties on the arterial stresses were also investigated. Higher arterial stresses were observed at the proximal end of the plaque. The Multilink–Vision stent induced lesser stress concentrations due to the high stiffness of the Cobalt Chromium material and thinner strut thickness. The stent-induced arterial stress concentrations were positively correlated with the reported in-stent restenosis rates, with a correlation coefficient of 0.992. Stent deployment initiated at the center of the lumen led to less arterial stress variation, while deployment closer to the thinner edge of the plaque causes higher arterial stresses. The friction between the stent and tissue was found to contribute to larger stress alternations for the plaque only. Increased plaque stiffness resulted in a reduced arterial stress concentration and clinical restenosis rate. Results presented herein suggested that arterial stresses serve as a comprehensive index factor to predict the occurrence of in-stent restenosis, which will facilitate the new stent design and surgical planning.

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Abstract 15274: Post-stenting Changes in the Coronary Geometry and In-stent Restenosis in Angulated Coronary Lesions: Comparison Between Platinum Chromium and Cobalt Chromium Everolimus-eluting Stents

Circulation ◽

10.1161/circ.132.suppl_3.15274 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Toshiyuki Kimura ◽

Nozomi Watanabe ◽

Nehiro Kuriyama ◽

Yoshisato Shibata

Keyword(s):

Stent Implantation ◽

De Novo ◽

Cobalt Chromium ◽

Stent Restenosis ◽

Coronary Stent Implantation ◽

Durable Polymer ◽

Coronary Lesions ◽

Cyclic Changes ◽

In Stent Restenosis

Purpose: Geometric changes in the coronary arteries at the site of coronary stent implantation can lead wall shear stress reduction with decreased coronary flow, which affect the clinical outcome after coronary intervention. Newly developed Platinum Chromium (PtCr)-Everolimus-eluting stent (EES) is expected to improve vessel conformability and restore the natural shape of the vessel with its modified scaffold design, using the same durable polymer and antiproliferative drug as the Cobalt Chromium (CoCr)-EES. The aim of this study was to investigate the long-term effect of PtCr-EES implantation on in-stent restenosis in angulated coronary lesions, comparing with CoCr-EES. Methods: This retrospective study included 250 lesions with CoCr-EES implantation and 217 lesions with PtCr-EES implantation for de novo angulated lesions (>45-degree by quantitative coronary angiography). The angle of the lesions was measured in diatole and systole, and cyclic changes in the coronary angle >20 degree was defined as hinge-like motion. Long-term coronary in-stent restenosis was defined as >50% angiographic stenosis in 8 month after the procedure. Results: Changes in maximum coronary angle at the site of stent implantation were significantly smaller in PtCr-EES group than in CoCr-EES group compared with original angle (20.65±15.42 vs. 26.25±18.36 degree, p <0.01). There were no significant differences in the occurrence of significant in-stent restenosis between PtCr-EES and CoCr-EES (6.7% vs 10.1%, p=0.32). CoCr-EES tended to show more restenosis than PtCr-EES (12.9% vs. 0.0%, p=0.07) in extremely angulated lesions (>100-degree). Interestingly, in the lesions with hinge-like motion, PtCr-EES group showed significantly higher rate of restenosis compared with CoCr-EES group (26.3% vs 7.7%, p= 0.04). Conclusions: In comparison with CoCr-EES, PtCr-EES tended to restore the original curvature of the coronary vessels, and this may lead less restenosis rate in extremely angulated lesions. However, PrCr-EES might have adverse effect on long-term result after coronary stenting in the lesion with hinge-like cyclic motion.

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