Abstract 14342: Relationship Between Peri-Strut Low Intensity Areas and Vascular Healing Response After Everolimus-Eluting Bioresorbable Scaffold Implantation: an Optical Coherence Tomography Study

Abstract

Objects: Peri-strut low intensity areas (PLIA) surrounding stent struts on optical coherence tomography (OCT) images has been histologically related to the delayed healing and inflammation, and have been previously associated with neointimal proliferation particularly in first generation drug-eluting stent era. However, the relationship between PLIA and bioresorbable vascular scaffolds (BRS) implantation remains to be clarified. Methods: Of 149 patients treated with the everolimus-eluting BRS at a single institution and followed-up for at least 6 months, 38 patients (50 lesions) underwent follow-up coronary angiography including OCT 11.0 ± 2.1 months after BRS implantation. All patients were prescribed lifelong aspirin (100mg/d) and prasugrel (10mg/d) for at least 6 months. The mean- and percent- neointimal area were evaluated by OCT. PLIA was defined as a peri-strut region with a homogenous lower intensity appearance than the surrounding tissue on OCT images without significant signal attenuation and was graded as follows:grade 0, no PLIA; grade 1, <1 quadrant; grade 2, ≥1 but <2 quadrants; grade 3, ≥2 quadrants but <3 quadrants; and grade 4, ≥ 3 quadrants. Additionally, all patients were divided into two groups (PLIA+ group, N=35 and PLIA- group,N=15). Results: The frequency of any PLIA within the scaffold segment was 70.0% (35/50 scaffolds). Mean PLIA grade score was 0.72± 0.77 [Median value (interquartile range), 0.51 (0, 1.07)]. There were significant positive correlations between PLIA score and both mean- (R=0.55,p<0.01) and percent- neointimal area (R=0.58,p<0.01). Both mean- and percent- neointimal area were significantly higher in the PLIA+ group than in the PLIA- group (1.95±0.65 vs. 1.51±0.27 mm 2 , p< 0.01 and 24.0±7.0 vs. 17.4±3.6 %, p< 0.01, respectively).Furthermore, when lesions were divided in 3 groups (group of PLIA score 0, N=15; group of 0<PLIA score<1, N=20; group of 1 < PLIA score, N=15), mean- and percent- neointima area were different among 3 groups (1.51±0.27 vs.1.66±0.39 vs.2.39±0.73 mm 2 , p<0.01; 17.4±3.7 vs.21.6±5.0 vs. 27.4±8.1 %, p<0.01). Conclusion: The presence and extent of PLIA after BRS implantation on OCT imaging appeared to be significantly associated with neointimal formation.