Background: Recent pathological studies have demonstrated that peri-strut low intensity area (PLIA) seen on optical coherence tomography (OCT) imaging represents the presence of fibrinogen and/or extracellular matrix. We sought to assess the clinical prevalence of PLIA and its relation to neointimal proliferation after the implantation of sirolimus- (SES) and paclitaxel-eluting stents (PES) in humans.
Methods: Seventy patients underwent 6-months follow-up OCT after SES (43 stents) or PES (37 stents) implantation. PLIA was defined as a region around stent struts with homogenous lower intensity than surrounding tissue on OCT images without signal attenuation. The incidence of stent struts with PLIA (+PLIA struts) was calculated as the number of +PLIA struts/number of all struts (%).
Results: PES showed a higher incidence of stents with PLIA than SES (86% vs. 58%; p=0.005) with a higher prevalence of +PLIA struts (27.8±21.9% vs. 10.9±11.0%; p=0.0008). SES with PLIA showed a significantly greater neointimal thickness (NIT) than SES without PLIA (p=0.02), while PES showed a similar tendency (p=0.19). In a detailed strut basis analysis, average NIT on +PLIA struts were significantly greater than that on -PLIA struts in both SES and PES. In addition, average NIT was positively correlated with the prevalence of +PLIA struts (SES: Rho=0.73; p<0.0001, PES: Rho=0.58, p=0.0005) in both stents.
Conclusions: The prevalence of PLIA was significantly higher in PES than in SES. The presence and extent of PLIA might be associated with intimal thickening after 1st-generation DES implantation.
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