scholarly journals Association of global and local low endothelial shear stress with high-risk plaque using intracoronary 3D optical coherence tomography: Introduction of ‘shear stress score’

2016 ◽  
Vol 18 (8) ◽  
pp. 888-897 ◽  
Author(s):  
Yiannis S. Chatzizisis ◽  
Konstantinos Toutouzas ◽  
Andreas A. Giannopoulos ◽  
Maria Riga ◽  
Antonios P. Antoniadis ◽  
...  
Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Yiannis S Chatzizisis ◽  
Konstantinos Toutouzas ◽  
Andreas A Giannopoulos ◽  
Maria Riga ◽  
Antonios P Antoniadis ◽  
...  

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.


2016 ◽  
Vol 67 (13) ◽  
pp. 372
Author(s):  
Yiannis S. Chatzizisis ◽  
Konstantinos Toutouzas ◽  
Andreas Giannopoulos ◽  
Maria Riga ◽  
Antonios Antoniadis ◽  
...  

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Anna Kotsia ◽  
Michail Papafaklis ◽  
Tesfaldet Michael ◽  
Bavana Rangan ◽  
Matthias Pelz ◽  
...  

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.


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Takao Sato ◽  
Mohamed Abdel-Wahab ◽  
Mohamed El-Mawardy ◽  
Ralph Tölg ◽  
Gert Richardt

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.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
Y Fukuyama ◽  
H Otake ◽  
F Seike ◽  
H Kawamori ◽  
T Toba ◽  
...  

Abstract Background The direct relationship between plaque rupture (PR) that cause acute coronary syndrome (ACS) and wall shear stress (WSS) remains uncertain. Methods From the Kobe University ACS-OCT registry, one hundred ACS patients whose culprit lesions had PR documented by optical coherence tomography (OCT) were enrolled. Lesion-specific 3D coronary artery models were created using OCT data. Specifically, at the ruptured portion, the tracing of the luminal edge of the residual fibrous cap was smoothly extrapolated to reconstruct the luminal contour before PR. Then, WSS was computed from computational fluid dynamics (CFD) analysis by a single core laboratory. Relationships between WSS and the location of PR were assessed with 1) longitudinal 3-mm segmental analysis and 2) circumferential analysis. In the longitudinal segmental analysis, each culprit lesion was subdivided into five 3-mm segments with respect to the minimum lumen area (MLA) location at the centered segment (Figure. 1). In the circumferential analysis, we measured WSS values at five points from PR site and non-PR site on the cross-sections with PR. Also, each ruptured plaque was categorized into the lateral type PR (L-PR), central type PR (C-PR), and others according to the relation between the site of tearing and the cavity (Figure. 2). Results In the longitudinal 3-mm segmental analysis, the incidences of PR at upstream (UP1 and 2), MLA, and downstream (DN1 and 2) were 45%, 40%, and 15%, respectively. The highest average WSS was located in UP1 in the upstream PR (UP1: 15.5 (10.4–26.3) vs. others: 6.8 (3.3–14.7) Pa, p&lt;0.001) and MLA segment in the MLA PR (MLA: 18.8 (6.0–34.3) vs. others: 6.5 (3.1–11.8) Pa, p&lt;0.001), and the second highest WSS was located at DN1 in the downstream PR (DN1: 5.8 (3.7–11.5) vs. others: 5.5 (3.7–16.5) Pa, p=0.035). In the circumferential analysis, the average WSS at PR site was significantly higher than that of non-PR site (18.7 (7.2–35.1) vs. 13.9 (5.2–30.3) Pa, p&lt;0.001). The incidence of L-PR, C-PR, and others were 51%, 42%, and 7%, respectively. In the L-PR, the peak WSS was most frequently observed in the lateral site (66.7%), whereas that in the C-PR was most frequently observed in the center site (70%) (Figure. 3). In the L-PR, the peak WSS value was significantly lower (44.6 (19.6–65.2) vs. 84.7 (36.6–177.5) Pa, p&lt;0.001), and the thickness of broken fibrous cap was significantly thinner (40 (30–50) vs. 80 (67.5–100) μm, p&lt;0.001), and the lumen area at peak WSS site was significantly larger than those of C-PR (1.5 (1.3–2.0) vs. 1.4 (1.1–1.6) mm2, p=0.008). Multivariate analysis demonstrated that the presence of peak WSS at lateral site, thinner broken fibrous cap thickness, and larger lumen area at peak WSS site were independently associated with the development of the L-PR. Conclusions A combined approach with CFD simulation and morphological plaque evaluation by using OCT might be helpful to predict future ACS events induced by PR. Funding Acknowledgement Type of funding source: None


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