Abstract 18189: Neointimal Response to Everolimus-eluting Bioresorbable Scaffolds Implanted at Bifurcating Coronary Segments: An Optical Coherence Tomography Study

Background: Previous studies have described different patterns of neointimal coverage between the outer wall and inner wall at coronary bifurcations lesions (BL) treated with metallic drug-eluting stents (DES) due to endothelial shear stress. Everolimus-eluting bioresorbable scaffolds (BRS) have thicker struts and could therefore have a stronger influence on endothelial shear stress compared to DES. However, the neointimal coverage of BL treated with BRS has not been adequately studied. We sought to evaluate the vascular response to BRS struts deployed at BL using optical coherence tomography (OCT). Methods: 50 patients (64 lesions) underwent follow-up OCT 11.0 ± 2.1 months after BRS implantation. Cross-sectional area of BL with a side branch more than 1mm using OCT was analyzed every 200μm. All images were divided into 3 regions according to shear stress: the 1/2 circumference of the vessel opposite to the ostium (OO), side branch ostium (SO), and the vessel wall adjacent to the ostium (AO). %uncovered strut of all struts and the averaged neointimal thickness (NIT) in 3 regions were evaluated. Additionally, to assess the impact of the side branch size on neointimal proliferation in BL, we calculated the ratio of the diameter of side branch ostium (Ds) to the diameter of main branch (Dm) (Ds/Dm) and divided patients into two groups based on median value of Ds/Dm of 0.318 as follow: large ratio side branch group (LRSB, n=32) and small ratio side branch group (SRSB, n=32). Results: Mean BRS diameter and length were 3.01±0.37 and 20.7±5.5mm. Mean diameter of all side branches was 1.69±0.51mm. In all patients, there was a significant difference in NIT among 3 regions (OO, 121±66 vs. AO, 96±32 vs. SO, 82±43μm, p=0.03). A significant difference was shown in %uncovered strut among 3 regions (OO, 0.45 vs. AO, 1.5 vs. SO, 4.7%, p=0.03). Further, in LRSB group, there was a significant difference in NIT among 3 regions (OO, 130±63 vs. AO, 92±38 vs. SO, 75±39 μm, p=0.01), and a significant difference was shown in %uncovered strut among 3 regions (OO, 0.37 vs. AO, 2.0 vs. SO, 8.8%, p=0.01). Conclusion: Different patterns of neointimal coverage are observed between the outer wall and inner wall of BL treated with BRS. Neointimal coverage is least at and adjacent to large side branches.

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Neointimal Coverage on Drug-Eluting Stent Struts Crossing Side-Branch Vessels Using Optical Coherence Tomography

The American Journal of Cardiology ◽

10.1016/j.amjcard.2010.01.013 ◽

2010 ◽

Vol 105 (11) ◽

pp. 1565-1569 ◽

Cited By ~ 8

Author(s):

Ae-Young Her ◽

Byoung Kwon Lee ◽

Jae-Min Shim ◽

Jung-Sun Kim ◽

Byoung-Keuk Kim ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Side Branch ◽

Drug Eluting Stent ◽

Optical Coherence ◽

Drug Eluting ◽

Neointimal Coverage

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Abstract 13969: Effect of Endothelial Shear Stress on the Serial Changes of Vein Grafts Assessed by Optical Coherence Tomography during the First Year After Coronary Artery Bypass Graft Surgery: Analysis from the CABG-PRO Study

Circulation ◽

10.1161/circ.130.suppl_2.13969 ◽

2014 ◽

Vol 130 (suppl_2) ◽

Author(s):

Anna Kotsia ◽

Michail Papafaklis ◽

Tesfaldet Michael ◽

Bavana Rangan ◽

Matthias Pelz ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Shear Stress ◽

Bypass Graft ◽

Plaque Burden ◽

Optical Coherence ◽

Lumen Area ◽

Vein Grafts ◽

Late Failure ◽

Endothelial Shear Stress

Introduction: Saphenous vein grafts (SVGs) have high rates of both early (≤ 1 year) and late failure following coronary arterial bypass graft surgery (CABG). Hypothesis: Endothelial shear stress (ESS) is a critical determinant of the natural history of coronary atherosclerosis, but the influence on the structural changes of SVGs has not been studied. We evaluated the effect of ESS on the serial anatomic outcomes of SVGs assessed by optical coherence tomography (OCT) during the first postoperative year. Methods: We performed 3-dimensional SVG reconstruction in 8 SVGs using fusion of angiographic and OCT data 5-7 days after surgery (baseline) and at 12-month follow-up. Baseline ESS was assessed using computational fluid dynamics. The reconstructed SVGs were divided in consecutive 3-mm segments (n=181), and we assessed the association of baseline ESS with the anatomic outcomes in the corresponding segments at follow-up: change in lumen area and plaque burden, and neointimal area at follow-up. Baseline ESS was categorized according to the tertiles of the ESS frequency distribution. Results: Median baseline ESS in SVGs was 0.48 Pa [IQR: 0.37-0.61 Pa]). Baseline low ESS was associated with: (i) the largest decrease in lumen area (low ESS category: -8.72±0.95 mm2 vs. moderate ESS category: -5.67±0.95 mm2 vs. high ESS category: -3.64±0.95 mm2; p<0.001 low vs moderate and high ESS category), (ii) the largest increase in plaque burden (low ESS category: 24.3±3.4% vs. moderate ESS category: 22.6±3.4% vs. high ESS category: 20.9±3.4%; p=0.011 low vs high ESS category), and (iii) the largest neointimal area at 12 months (low ESS category: 4.02±0.45 mm2 vs. moderate ESS category: 3.65±0.45 mm2 vs. high ESS category: -3.57±0.45 mm2; p=0.020 low vs moderate ESS category, and p=0.009 low vs high ESS category). Conclusions: SVG areas with the lowest local ESS develop the largest lumen constriction, plaque burden increase and neointima formation. These findings provide important insights into the pathogenesis of early SVG failure.

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Abstract 12063: High-risk Plaque Co-localizes With Low Endothelial Shear Stress and Expansive Remodeling in Human Coronary Arteries: A 3D Optical Coherence Tomography Study

Circulation ◽

10.1161/circ.132.suppl_3.12063 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Yiannis S Chatzizisis ◽

Konstantinos Toutouzas ◽

Andreas A Giannopoulos ◽

Maria Riga ◽

Antonios P Antoniadis ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Shear Stress ◽

High Risk ◽

Coronary Arteries ◽

Vascular Remodeling ◽

Pool Size ◽

Optical Coherence ◽

Fibrous Cap ◽

Endothelial Shear Stress

Background: High risk plaque accounts for the majority of acute coronary events. Low endothelial shear stress (ESS) is a key factor of the natural history of atherosclerosis. The role of ESS in high risk plaque formation is not well studied in man. Hypothesis: To explore the association of low ESS with high risk plaque and to identify the ESS milieu and vascular remodeling response in high risk vs. non high risk plaque. Methods: 35 coronary arteries from 30 patients were 3D reconstructed with fusion of coronary angiography and optical coherence tomography (Fig A-D) . ESS was calculated in the 3D reconstructed arteries using computational fluid dynamics (Fig E) and classified into low, moderate and high in 3 mm long segments. In each segment: i) fibroatheromas were classified into high risk and non high risk based on fibrous cap thickness and lipid pool size ii) vascular remodeling was classified into constrictive, compensatory and expansive. Results: Fibroatheromas in low ESS segments had significantly thinner fibrous cap compared to high ESS segments (89±84 vs.138±83 μm, p<0.05). Lipid pool size was comparable across all ESS categories. The majority of low ESS segments co-localized with high risk plaques (29 vs. 9%, p<0.05), whereas the majority of high ESS co-localized with non high risk plaques (24 vs. 9%, p<0.05, Fig F ). Compensatory and expansive remodeling was the predominant remodeling response in low ESS segments containing high risk plaques. In non-stenotic fibroatheromas (expansive or compensatory remodeling) low ESS was predominantly associated with high risk plaques (29 vs. 3%, p<0.05) whereas high ESS was associated with non high risk plaques (Fig F) . Conclusions: Novel combined anatomic and functional imaging with 3D OCT showed that low ESS and non-constrictive remodeling are associated with high risk plaque in man. Further studies are needed to assess the role of ESS and vascular remodeling in high risk plaque rupture and precipitation of clinical outcomes.

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