Abstract 4362: Incomplete Stent Apposition Does Not Impact on the Angioscopic Neointimal Coverage Following Drug-eluting Stent Implantation
Background: Insufficient neointimal coverage following drug-eluting stent implantation may result in adverse outcomes. Incomplete stent apposition has been reported as a possible factor of stent thrombosis. We sought to investigate the relationship between the angioscopic neointimal coverage grades and various types of incomplete stent apposition (ISA).
Methods: We evaluated 58 stents (51 sirolimus-eluting stents; 7 zotarolimus-eluting stents) using both angioscopy (Vecmova, Clinical Supply) and IVUS (40 MHz, Boston Scientific). Follow up interval ranged 10±6 months. Neointimal coverage was classified into 4 grades according to the transparency of the stent struts: stent struts were fully visible, similar to immediately after implantation (G0); struts bulged into the lumen and, although covered, were still transparently visible (G1); struts were embedded by the neointima, but were translucently seen (G2); struts were fully embedded and were invisible (G3). IVUS was performed both after stent implantation and at follow-up. ISA was classified as: acute ISA (resolved or persisted); late acquired ISA.
Results: Of the 58 stents, initial IVUS revealed acute ISA in 17 lesions (29%). Angioscopic grades at follow-up were distributed as: G0=2 (3%), G1=35 (60%), G2=11 (19%), and G3=10 (17%). Incidences of acute ISA at baseline were similarly distributed among the 4 angioscopic neointimal grades: 0% in G0, 31 % in G1, 36% in G2 and 20% in G3 (P=0.7). Of 17 acute ISA, ISA resolved in 7 lesions. There were no significant differences in the angioscopic neointimal coverage grades between acute persisted ISA and acute resolved ISA (G1=80%, G2=20% versus G1=42%, G2=29%, G3=29%, P=0.1). At follow up, 7 late acquired ISA were identified. Angioscopic grades were similarly distributed in late acquired ISA: G0=1, G1=4, G2=1 and G3=1 (P=0.4).
Conclusions: Incomplete stent apposition, including acute resolved, acute persisted and late acquired ISA, does not impact on angioscopic grades of the neointimal coverage following drug-eluting stent implantation.