Abstract 4404: Lower Incidence of Persistent Imtramural Thrombus in Sirolimus-Eluting Stent Coated With a Novel Bioabsorbable Salicylate-Based Polymer in Comparison With Durable Polymeric Surface Coating: Angioscopic and Histological Evaluations in Porcine Coronary Artery Model
Background: Chronic inflammation and hypersensitivity reactions induced by permanent polymers used in current drug-eluting stent (DES) may contribute to late thrombosis and restenosis. We evaluated a novel sirolimus-eluting stent coated with bioabsorbable salicylate-based polymer.
Methods: Durable polymeric sirolimus-eluting stents (Cypher®, n=26) and bioabsorbable salicylic acid/adipic acid polymer coated metal stents containing sirolimus (SA/AA+S, n=32) were randomly implanted in pig coronary arteries using QCA to optimize stent apposition. Angioscopic and histological grading of intramural thrombus and intimal thickness were assessed at 1 and 3 months post implantation.
Results: At 1 month, there was no significant difference between Cypher and SA/AA+S in terms of angioscopic and histological intramural thrombus grading (P=0.100). Histological neointimal thickness was similar between two group both at 1 and 3 month (1M Cypher:, 0.19±0.19mm, SA/AA+S 1M:0.10±0.06mm, P=0.25, 3M Cypher: 0.33±0.20mm, SA/AA;S:0.36±0.27mm P=0.79) From 1 to 3 months, the angioscopic grading of intimal thickness increased in both groups, accordingly the angioscopic grading of intramural thrombus beneath thicker neointima was decreased in both groups; however, histology revealed intramural thrombus persist at 3 months without change from 1 month only in Cypher, while significantly decreased in SA/AA+S (P<0.001).
Conclusions: Sirolimus-eluting stent coated with novel bioabsorbable salicylate-based polymer showed lower levels of histological intramural thrombus at three months post implant compared to Cypher stent.