Abstract 6009: Characteristics of Late Incomplete Stent Apposition: A Comparison with Sirolimus-, Paclitaxel- and Zotarolimus-Eluting Stents
Background: Characteristics of late incomplete stent apposition (LISA) in diverse drug-eluting stents have not been systematically examined. The aim of this study was to investigate the morphometric parameters of LISA following sirolimus- (SES), paclitaxel- (PES) and zotarolimus-eluting stents (ZES: RESOLUTE stent).
Method: LISA was defined as separation of at least 1 stent strut from the vessel wall with evidence of blood speckle behind the strut, where post-stent implantation IVUS revealed complete apposition. A total of 29 LISA cases (12 SES, 10 PES, 7 ZES) were identified and included in this analysis. Corresponding cross-sections at post-procedure were selected for comparison. Vessel (VA), lumen, peri-stent tissue (TA), and stent area (SA) were measured in the LISA arc as referenced to stent center.
Result: LISA area was 2.4±5mm2 in SES, 2.2±2.7mm2 in PES and 1.0±0.6mm2 in ZES. Contributions of vessel expansion (ΔVA), peri-stent tissue reduction (-ΔTA), and stent recoil (-ΔSA) to the development of LISA are summarized in Figure⇓. While VA significantly increased from post-procedure to follow-up in SES (4.6±1.7 to 7.0±2.5mm2, p<0.01) and tended to increase in PES (3.6±1.7 to 5.7±3.8mm2, p=0.06), ZES showed no statistically significant change in VA. Per patient analysis also demonstrated that vessel expansion was the predominant mechanism in 83% of LISA cases in SES, 60% in PES and 43% of ZES.
Conclusion: The magnitude and mechanism of LISA appear to be different among 3 drug-eluting stents, possibly due to varying vessel response to different types of stent components.