Abstract 14672: Very Late Stent Thrombosis After Sirolimus-Eluting Stent Implantation Is Associated With Expansive Vessel Remodeling
Background: Very late stent thrombosis (ST) has been reported as an adverse event unique to drug-eluting stents. The aim of this study was to compare the arterial response in lesions with early (within 30 days), late (between 31 and 365 days), or very late ST (beyond 1 year) after sirolimus-eluting stent (SES) implantation assessed by intravascular ultrasound (IVUS).
Methods: We analyzed 124 patients with definite ST who underwent IVUS at baseline and/or event in the RESTART registry, which is a Japanese nationwide registry of patients with ST after SES implantation (early ST, n=66, late ST, n=27, very late ST, n=31). ST was identified using the Academic Research Consortium definition.
Results: At the time of ST, very late ST showed a significantly greater maximum vessel area along the stented segment than early and late ST (early ST, 17.4±4.1 mm2, late ST, 20.6±7.0 mm2, very late ST, 26.1±7.5 mm2, p<0.0001), despite no statistical difference in maximum vessel areas at baseline (17.0±4.8 mm2, 19.4±5.7 mm2, 19.2±6.1mm2, p=0.084, respectively). In patients with serial IVUS, maximum vessel area increase from baseline to event was 0.4% in early, 3.0% in late, and 28.9% in very late ST (p<0.0001). To further characterize this observation, a mm-by-mm analysis revealed an inverse association between peri-stent plaque area at baseline versus vessel expansion at the time of ST in very late ST (p<0.0001).
Conclusions: The substantial difference in arterial response behind the stent suggests pathophysiologic mechanisms of very late ST that are distinct from those with either early or late ST. Subset IVUS analysis demonstrated that greater expansive vessel remodeling occurred on the less diseased side of the vessel wall at baseline.
- © 2010 by American Heart Association, Inc.