Abstract 15492: IVUS Assessment of Patients with Early, Late and Very Late Stent Thrombosis after Sirolimus-Eluting Stent Implantation: Final IVUS Results From the RESTART Registry
Background: RESTART is the first nationwide multicenter registry of patients who developed definite stent thrombosis (ST) after sirolimus-eluting stent (SES) implantation. The aim of this IVUS study was to investigate the mechanical and biological characteristics of stented lesions with early, late, or very late ST, compared with non-ST patients.
Methods: From 105 centers, 124 ST patients (66 early ST: 27 late ST: 31 very late ST) who underwent IVUS at baseline and/or event were enrolled and compared with control patients. Definite ST was independently adjudicated according to the Academic Research Consortium definition, and all IVUS images were analyzed at an independent core laboratory.
Results: Among ST patients, baseline clinical and procedural characteristics were similar, except for younger age and less renal dysfunction in very late ST. Minimum stent area was significantly smaller in early and late ST than control groups (4.6±1.5 vs. 5.5±1.8 mm2 for early vs. control, p=0.002; 4.6±1.2 vs. 5.5±1.5 mm2 for late vs. control, p=0.016), while very late ST showed no significant difference compared with control (5.2±2.0 vs. 5.6±1.9 mm2, p=0.264). At the time of ST, very late ST showed a significantly greater maximum vessel area along the stented segment than early and late ST (17.4±4.1, 20.6±7.0, 26.1±7.5 mm2, respectively, p<0.0001), despite no difference observed at baseline. Similar results were also observed in comparisons with control (Figure). Incomplete stent apposition (ISA) at event was frequently observed in all ST (early 19%, late 58%, very late 56%, p=0.013), while ISA at follow-up was less frequent in the control groups (12-13%).
Conclusions: Significant stent underexpansion was associated primarily with early and late ST, while very late ST showed a substantial difference in arterial response behind the stent. These results suggest pathophysiologic mechanisms of very late ST that are distinct from early and late ST.
- © 2011 by American Heart Association, Inc.