Abstract 4481: Angioscopic Comparison of Arterial Healing Following Paclitaxel- Versus Sirolimus-Eluting Stent Implantation in Patients
Several studies have shown that in-stent late loss (LL) at follow-up was greater in paclitaxel-eluting stent (PES) than in sirolimus-eluting stent (SES). We hypothesized the differences in LL are reflected in different healing processes. To assess the healing processes following PES and SES, follow-up angioscopy and angiography were performed 9±1 months after 19 PES (Taxus Express II, Boston Scientific) and 30 SES (Cypher, Cordis) implanted de novo in the native coronary artery. Dominant degree and heterogeneity of neointimal coverage (NIC) were examined by angioscopy. Existence of thrombi was also explored. NIC was defined as: grade 0 = stent struts were exposed; grade 1 = struts bulged into the lumen, although they were covered; grade 2 = struts were embedded, but were seen translucently; grade 3 = struts were invisible. If different NIC grades of more than or equal to 1 grade were present, the NIC was judged as heterogeneous. LL was slightly, but significantly greater in PES (0.44±0.49mm) than in SES (0.08±0.15mm, P<0.0001). While 70% of SES showed the dominant NIC of grade 1, PES showed widely dispersed NIC (Figure⇓). NIC was more heterogeneous in PES (74%) than in SES (43%, P=0.04). Thrombi were present at the site of grade 0/1, and were more frequently observed in PES (57%) than in SES (26%, P=0.045). Arterial healing following stenting was markedly different between the different platforms of drug-eluting stents. Both intra- and inter-stent heterogeneities of NIC grades were more significant in PES, associated with higher frequency of thrombi and exposed struts than SES.