Abstract 2460: Competitive Comparison Of Reendothelialization in Drug Eluting Stents
Background: There is rising concern about a disparity in arterial healing following implantation of current drug eluting stents (DES). Reendothelialization of stent surface is a critical event for arterial healing as it relates to late thrombotic risk.
Methods: New Zealand White Rabbits received bilateral implantation of DES with different stent platform, polymer and drug for 14 and 28 days, respectively. Total drug content was 100 μg for everolimus (A), 111 μg for sirolimus (B), 79 μg for paclitaxel (C) and 130 μg for ABT-578-eluting stents (D). Stented arteries were cut longitudinally, one half processed for confocal microscopy and the other submitted for SEM analysis. CD31 and thrombomodulin were used as endothelial cell markers and semi-quantified as a visual estimation score by a blinded observer; Calibrated quantification of endothelialization was performed on high-resolution (x200) images of individual stent struts. Endothelialization was measured above and between stent struts and expressed as percentage.
Results: The percentage of endothelialization was significantly greater in everolimus - as compared to sirolimus and ABT-578-eluting stents at 14 days (see figure⇓). Semi-quantification of CD31 stain confirmed these findings and thrombomodulin was not expressed in reendothelialized surfaces. At 28 days, endothelialization was incomplete in all DES, without significant differences among groups.
Conclusion: Current DES show substantial differences in reendothelialization, with greatest endothelialization observed in everolimus-eluting stents at 14 days. Clinical studies are needed to prove the significance of these findings.