Abstract 3055: Drug Eluting Stents and Delayed Arterial Healing: Paclitaxel Eluting Stents are associated with Increased Arterial Wall Inflammatory Changes when compared to Sirolimus Eluting Stents in a Porcine Restenosis Model
Background: Questions still remain regarding differences in DES platforms. The present study compared the arterial healing and inflammatory response after the implant of sirolimus eluted stents (SES) and paclitaxel eluted stents (PES).
Methods: In a pig model of coronary restenosis (balloon overstretch: artery ratio = 1:1.2), 16 animals (44 vessels) were randomized to either SES or PES. Local arterial responses were assessed by morphometric histopathological analysis, scanning electron microscopy and measurements of local arterial wall expression of specific proteins by Western Blot (densitometry), 30 days after the interventional procedure.
Results: There were similar injury scores in both DES groups confirming the uniformity of the model. PES was more frequently associated with worse inflammatory scores than SES as assessed by electron microscopy (fig 1a⇓). Endothelialization was similar in both groups. PES had higher scores of fibrin deposition than SES, though not statistically significant (fig 1b⇓). PES when compared to SES had higher levels of arterial wall expression of PDGF (5460±629 pixels (P) vs. 4251±223 P ; p=0.0007), lower levels of expression of endothelial precursor cells identified by CD31 (4147±3254 P vs. 4619±3070 P ; p=0.03) and Von Willebrand Factor (5040±453 P vs 6383±664 P; p=0.0005). Both platforms had similar expression of IL-6 and VEGF.
Conclusion: In a pig model of coronary restenosis, non-overlapped PES showed significantly higher inflammatory scores than non-overlapped SES segments. This is further corroborated by higher expression of PDGF. Future clinical trials are needed to further understand the differences between DES platforms.