Optical Coherence Tomography Versus Intravascular Ultrasound and Angiography to Guide Percutaneous Coronary Interventions

Background: Specific algorithms for use of optical coherence tomography (OCT) to guide percutaneous coronary intervention (PCI) are scarce. Also, the relative benefits of intravascular imaging guidance have not been tested against an optimized angiography-guided PCI strategy. In iSIGHT (Optical Coherence Tomography Versus Intravascular Ultrasound and Angiography to Guide Percutaneous Coronary Interventions), we aimed to investigate whether OCT-guided PCI achieves noninferior stent expansion compared with intravascular ultrasound (IVUS) guidance and if both imaging modalities lead to superior stent expansion compared with an optimized angiography-based strategy. Methods: Patients ≥18 years old undergoing PCI for ≥1 lesion in native coronaries of 2.25 to 4.00 mm in diameter were randomized 1:1:1 to OCT-, IVUS-, or angiography-guided PCI. Predetermined guidance protocols were applied in all groups. An external elastic membrane–based protocol was used for stent sizing by OCT and IVUS. The primary end point was noninferiority of stent expansion (minimum stent area ≥90% of the average reference lumen area), measured by post-PCI OCT, in OCT-guided versus IVUS-guided PCI (noninferiority margin, 6.5%). Results: One hundred fifty-one patients (156 lesions) were randomly allocated to OCT (51 lesions [32.7%]), IVUS (52 lesions [33.3%]), or angiography (53 lesions [34.0%]). Stent expansion with OCT guidance (98.01±16.14%) was noninferior to IVUS (91.69±15.75%; 1-sided lower 95% CI, 0.55 mm 2 ; P non-inferiority <0.001) and superior to angiography (90.53±14.84%, P =0.041). IVUS and angiography obtained similar stent expansions ( P =0.921). Stent edge dissection and periprocedural complication rates were not significantly different among the groups. Conclusions: Stent expansion with OCT guidance using a dedicated external elastic membrane–based sizing strategy was noninferior to that achieved with IVUS and superior to an optimized angiographic strategy. Registration: URL: plataformabrasil.saude.gov.br ; Unique identifier: 69968417.8.0000.5462.

Automatic segmentation of coronary lumen and external elastic membrane in intravascular ultrasound images using 8-layer U-Net

Background Intravascular ultrasound (IVUS) is the golden standard in accessing the coronary lesions, stenosis, and atherosclerosis plaques. In this paper, a fully automatic approach by an 8-layer U-Net is developed to segment the coronary artery lumen and the area bounded by external elastic membrane (EEM), i.e., cross-sectional area (EEM-CSA). The database comprises single-vendor and single-frequency IVUS data. Particularly, the proposed data augmentation of MeshGrid combined with flip and rotation operations is implemented, improving the model performance without pre- or post-processing of the raw IVUS images. Results The mean intersection of union (MIoU) of 0.937 and 0.804 for the lumen and EEM-CSA, respectively, were achieved, which exceeded the manual labeling accuracy of the clinician. Conclusion The accuracy shown by the proposed method is sufficient for subsequent reconstruction of 3D-IVUS images, which is essential for doctors’ diagnosis in the tissue characterization of coronary artery walls and plaque compositions, qualitatively and quantitatively.

Automatic Segmentation of Coronary Lumen and External Elastic Membrane in Intravascular Ultrasound Images Using 8-layer U-Net

Background: Intravascular ultrasound (IVUS) is the golden standard in accessing the coronary lesions, stenosis, and atherosclerosis plaques. In this paper, a fully-automatic approach by an 8-layer U-Net is developed to segment the coronary artery lumen and the area bounded by external elastic membrane (EEM), i.e. cross section area (EEM-CSA). The database comprises of single-vendor and single-frequency IVUS data. Particularly, the proposed data augmentation of MeshGrid combined with flip and rotation operations is implemented, improving the model performance without pre- or post-processing of the raw IVUS images.Results: The mean intersection of union (MIoU) of 0.937 and 0.804 for the lumen and EEM-CSA respectively were achieved, which exceeded the manual labeling accuracy of the clinician. Conclusion: The accuracy shown by the proposed method is sufficient for subsequent reconstruction of 3D IVUS images, which is essential for doctors’ diagnosis in the tissue characterization of coronary artery walls and plaque compositions, qualitatively and quantitatively.

Structural Thickening of Medial Layer in Coronary Artery With Spasm in Patients With Myocardial Infarction

Background The underlying pathophysiology of coronary artery spasm (CAS) remains unclear. We aim to determine whether coronary artery medial layer thickness is associated with CAS using optical coherence tomography. Methods and Results A total of 50 patients with previous myocardial infarction underwent optical coherence tomography of the left anterior descending artery: 20 with CAS and 30 without CAS. Intimal and medial layer areas were measured by planimetric analysis of optical coherence tomography images. The medial area/external elastic membrane (EEM) area was significantly greater in patients with than without CAS (0.13±0.01 versus 0.09±0.01, respectively, P <0.01), whereas the intimal area/EEM area was similar in the 2 groups. In patients without CAS, the relationship of intimal area/EEM area with medial area/EEM area and coronary diameter response to intracoronary injection of acetylcholine was characterized by an inverted U‐shaped curve ( y =−1.85 x 2 +0.81 x +0.01, R 2 =0.43, P <0.001) and a U‐shaped curve ( y =2993.2 x 2 −1359.6 x +117.1, R 2 =0.53, P <0.001), respectively. Thus, the medial layer became thin and the contractile response became weak in coronary arteries with greater intimal area in the non‐CAS patients. In contrast, in patients with CAS, the intimal area/EEM area had no significant relationship with the medial area/EEM area in either linear correlation analysis or quadratic regression analysis. Thus, even when the intimal layer thickened, the medial layer did not thin in patients with CAS. Conclusions The structural thickness of the coronary medial layer was increased in patients with CAS, which may provide mechanistic insight into the pathogenesis of CAS. Registration URL: https://www.upload.umin.ac.jp ; Unique identifier: UMIN000018432.

Automatic Segmentation of Coronary Lumen and External Elastic Membrane in Intravascular Ultrasound Images Using 8-layer U-Net

Background: Intravascular ultrasound (IVUS) is the golden standard in accessing the coronary lesions, stenosis, and atherosclerosis plaques. In this paper, a fully-automatic approach by an 8-layer U-Net is developed to segment the coronary artery lumen and the area bounded by external elastic membrane (EEM), i.e. cross section area (EEM-CSA). The database comprises of single-vendor and single-frequency IVUS data. Particularly, the proposed data augmentation of MeshGrid combined with flip and rotation operations is implemented, improving the model performance without pre- or post-processing of the raw IVUS images.Results: The mean intersection of union (mIoU) of 0.937 and 0.804 for the lumen and EEM-CSA respectively were achieved, which exceeded the manual labeling accuracy of the clinician. Conclusion: The accuracy shown by the proposed method is sufficient for subsequent reconstruction of 3D IVUS images, which is essential for doctors’ diagnosis in the tissue characterization of coronary artery walls and plaque compositions, qualitatively and quantitatively.

Intravascular ultrasound

Intravascular ultrasound represents the most established, well-validated, and widely used intracoronary imaging technology worldwide and was introduced approximately 25 years ago. Intravascular ultrasound enables the visualization of key anatomical structures of the coronary artery and saphenous or arterial grafts including the lumen, external elastic membrane, and adventitia and thereby provides the basis for the assessment of the degree of coronary artery stenosis, extent of atherosclerosis burden (i.e. global and local disease burden), and plaque composition. All this represents key information to plan and perform percutaneous coronary intervention procedures in native coronary artery disease or graft lesions and to estimate the risk for future cardiovascular events.

Automatic Segmentation of Coronary Lumen and External Elastic Membrane in Intravascular Ultrasound Images Using 8-layer U-Net

Background: Intravascular ultrasound (IVUS) is the golden standard in accessing the coronary lesions, stenosis, and atherosclerosis plaques. In this paper, a fully-automatic approach by an 8-layer U-Net is developed to segment the coronary artery lumen and the area bounded by external elastic membrane (EEM), i.e. cross section area (EEM-CSA). The database comprises of single-vendor and single-frequency IVUS data. Particularly, the proposed data augmentation of MeshGrid combined with flip and rotation operations is implemented, improving the model performance without pre- or post-processing of the raw IVUS images.Results: The mean intersection of union (mIoU) of 0.937 and 0.804 for the lumen and EEM-CSA respectively were achieved, which exceeded the manual labeling accuracy of the clinician.Conclusion: The accuracy shown by the proposed method is sufficient for subsequent reconstruction of 3D IVUS images, which is essential for doctors’ diagnosis in the tissue characterization of coronary artery walls and plaque compositions, qualitatively and quantitatively.

Abstract 15501: Repeated Social Defeat Exaggerates Cacl2-induced Abdominal Aortic Aneurysm Expansion by Suppression of Periaortic Fibrosis in Tissue Repair Phase

Background and Objective: Depression is an independent risk factor of cardiovascular disease and significantly associated with the prevalence of abdominal aortic aneurysm (AAA). We investigated the impact of repeated social defeat (RSD) on AAA formation. Methods and Results: Eight-week-old male WT mice were exposed to RSD by housing with a larger CD-1 mouse in a shared cage. They were subjected to vigorous physical contact daily for 10 consecutive days. Control mice were housed in the same cage without physical contact. After social interaction test to confirm depressive-like behaviors, mice underwent application of 0.5M calcium chloride (CaCl 2 ) on the infrarenal aorta. At one-week, maximum diameter and circumference of external elastic membrane were comparable between the two groups. The number of F-4/80 and MMP-9-positive cells in immunofluorescent images were also comparable. Consistently, fluorescent image taken by IVIS revealed no difference in MMP activity, suggesting that acute inflammatory response was comparable between the two groups. In contrast, at two weeks, maximum diameter and circumference of external elastic membrane were significantly increased in defeated mice ( p < 0.01). Intriguingly, periaortic fibrotic area in aneurysmal portion was markedly decreased in defeated mice (12.5х10 3 μm 2 vs. 3.7х10 3 μm 2 , Control vs. Defeat, p < 0.01). Consistently, accumulation of α-SMA-positive cells in adventitia of aneurysmal portion was much lesser in defeated mice (876 cells/mm 2 vs. 319 cells/mm 2 , Control vs. Defeat, p < 0.05), whereas those in tunica media of non-aneurysmal portion did not show any difference between the two groups. LPS-induced iNOS gene and protein expressions in bone marrow-derived macrophages (BMDMs) were significantly decreased in defeated mice, whereas the TGF-β-induced phosphorylation of Smad2 and ERK1/2 in primary cultured aortic VSMCs were comparable between the two groups. Conclusions: Our findings demonstrate that RSD enhances AAA expansion by suppressing the periaortic fibrosis following inflammatory response, and suggest that decreased NO production from accumulated macrophages contributes to the reduced VSMCs proliferation and collagen deposition.

Repeated social defeat exaggerates CaCl2-induced abdominal aortic aneurysm expansion by eliminating periaortic fibrosis in tissue repair phase: possible involvement of specific subtypes of macrophages

Background and objective Depression is an independent risk factor of cardiovascular disease (CVD) and significantly associated with the prevalence of abdominal aortic aneurysm (AAA). We have recently shown that repeated social defeat (RSD) precipitates depressive-like behaviors in apoE−/− mice and exaggerates atherosclerosis development by enhancing leukocyte activation. Here, we investigated the impact of RSD on AAA formation. Methods and results Eight-week-old male WT mice were exposed to RSD by housing with a larger CD-1 mouse in a shared home cage. They were subjected to vigorous physical contact daily for 10 consecutive days. Control mice were housed in the same gage without physical contact. After social interaction test to confirm depressive-like behaviors, defeated mice (28 of 48) and control mice (31 of 36) underwent application of 0.5 M calcium chloride (CaCl2) on the infrarenal aorta to induce AAA. At 1 week after application, maximum diameter and circumference of external elastic membrane were comparable between the two groups. The number of F-4/80, MMP-9, and TNF-α-positive cells in immunofluorescent images were also comparable. Further, in vitro bone marrow derived macrophages stimulation by LPS did not show any difference in mRNA expression levels of inflammatory cytokines, suggesting no discernable difference in acute inflammatory response between the two groups. In contrast, at 2 weeks after application, at the time point when MMP-9 and TNF-α-positive cells were scarcely observed, maximum diameter and circumference of external elastic membrane were significantly increased in defeated mice (0.72 mm vs. 0.90 mm, 1.59 mm vs. 2.00 mm, respectively, Control vs. Defeat, p&lt;0.01). Intriguingly, periaortic fibrotic area in aneurysmal portion was markedly decreased in defeated mice (12.5×103 μm2 vs. 3.7×103 μm2, Control vs. Defeat, p&lt;0.01). Consistently, accumulation of α-SMA-positive cells in adventitia of aneurysmal portion was much less in defeated mice than control mice (876 cells/mm2 vs. 319 cells/mm2, Control vs. Defeat, p&lt;0.05), whereas those in tunica media of non-aneurysmal portion did not show any difference between the two groups. We next focused on the segregated nucleus-containing atypical monocyte (SatM), specific subtypes of monocytes/macrophages that are involved in fibrosis in injured tissues during the healing phase. We could observe SatM fraction in AAA tissue of control mice using flow cytometry. We also found that mRNA expression level of C/EBPβ, an essential regulator for SatM differentiation, was markedly decreased by 76% in BM cells of defeated mice compared with control mice (p&lt;0.05). Conclusions Our findings demonstrate for the first time that RSD enhances AAA expansion by eliminating periaortic fibrosis in tissue repair phase, suggesting that the impaired resolution of acute inflammation after CaCl2 application contributes, at least in part, to the augmented expansion of AAA in defeated mice. Funding Acknowledgement Type of funding source: None

Circulating microRNA-21 as Stable Blood-Based Markers for Patients With ISR After PCI

It recently has been reported that the in-stent restenosis (ISR) of expanded area after percutaneous coronary intervention (PCI) within six months can become a serious postoperative complication. A real-time quantitative PCR was used to analyze the expression of serum miR-21 in 33 ISR and 37 non-ISR patients after PCI. Expression of miR-21 was significantly higher in the ISR group compared with that in the NISR group, and a similar trend also occurred in factor- (TNF-α) level, Interleukin -6 (IL-6) level, and plaque area (PLA). However, a contrary trend occurred in the external elastic membrane area (EEM) and minimal lumen area (MLA). This study suggests that the increased expression of serum miR-21 is related to ISR after PCI, and miR-21 can be a new predictor of ISR.