scholarly journals 246 Air pollution and coronary plaque vulnerability and instability: an optical coherence tomography study

2021 ◽  
Vol 23 (Supplement_G) ◽  
Author(s):  
Rocco Antonio Montone ◽  
Massimiliano Camilli ◽  
Michele Russo ◽  
Giulia La Vecchia ◽  
Giulia Iannaccone ◽  
...  

Abstract Aims Air pollution is an emerging key player in determining the residual risk of coronary events. However, pathophysiological mechanisms linking air pollution and coronary events have been not adequately investigated. We aimed at assessing the relationship between exposure to air pollutants and mechanisms of coronary instability evaluated by optical coherence tomography (OCT) in patients with acute coronary syndrome (ACS). Methods and results ACS patients undergoing OCT imaging were retrospectively selected. Mechanism of culprit lesion instability was classified as plaque rupture (PR) or intact fibrous cap (IFC) by OCT, and the presence of macrophage infiltrates (MØI) and thin-cap fibroatheroma (TCFA) at the culprit site was also assessed. Based on each case’s home address, exposure to several pollutants was evaluated, including particulate matter 2.5 (PM2.5), particulate matter 10 (PM10), and carbon monoxide (CO). Only patients with >2 years of available data on air pollution exposure prior to ACS were enrolled. We included 126 patients [median age 67.0 years (55.5–76.0), 97 (77.0%) male]. Sixty-six patients (52.4%) had PR as mechanism of plaque instability. Patients with PR were exposed to significantly higher PM2.5 levels compared to IFC, and PM2.5 was independently associated with PR [odds ratio per unit = 1.194, 95% CI: (1.036–1.377), P = 0.015]. Moreover, exposure to higher levels of PM2.5 was independently associated with the presence of TCFA and of MØI at the culprit site. Interestingly, PM2.5, PM10, and CO levels were positively and significantly correlated with serum levels of C-reactive protein. ROC curves were constructed to assess the ability of PM2.5 to predict the presence of plaque rupture, TCFA or MØI. The AUC for PM2.5 to predict plaque rupture was 0.62 (95% CI: 0.52–0.71, P = 0.018), for TCFA was 0.71 (95% CI: 0.61–0.80, P <0.001) and for MØI was 0.80 (95% CI: 0.71–0.88, P <0.001). Using a PM2.5 cut-off value of 13.40 μg/m3, the sensitivity and specificity for MØI were 81% and 66%, respectively. Conclusions We provide novel insights into the missing link between air pollution and increased risk of coronary events. In particular, exposure to higher concentrations of air pollutants is a risk factor for vulnerable plaque features and for plaque rupture as mechanism of coronary instability mediated by systemic and local plaque inflammation. Of importance, the thresholds of air pollutants that predicted the presence of vulnerable plaque features are far lower than commonly accepted safety thresholds used to start preventive measures for public health, suggesting that further efforts are needed in order to reduce the adverse effects on the cardiovascular system.

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<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<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<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<0.001), and the thickness of broken fibrous cap was significantly thinner (40 (30–50) vs. 80 (67.5–100) μm, p<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


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
S Kimura ◽  
K Hara ◽  
M Ohmori ◽  
R Tateishi ◽  
T Kaneda ◽  
...  

Abstract Background Many vulnerable plaques would progress without clinical events and might result in healed plaques (HPs). Histopathological or intracoronary image assessment of HPs has been reported. However, the morphological characteristics of HPs remain unclear yet. Purpose We sought to assess the healed vulnerable plaque components in patients with coronary artery lesions using optical coherence tomography (OCT) and coronary angioscopy (CAS). Methods We enrolled 47 patients with 50 native coronary artery lesions with angiographical severe stenosis (>90% diameter-stenosis) and without severe calcification (36 lesions with stable angina pectoris (SAP) and 14 acute coronary syndrome (ACS)) undergoing pre-intervention OCT and CAS. HPs was defined as layered phenotype on OCT. Lesion morphologies and plaque characteristics in lesions with HPs were assessed using OCT and CAS images. Results HPs were observed in 27 lesions (54.0%) and their prevalence were similar among each clinical status (SAP 52.8%, ACS 57.1%, p=1.00). Lesions with HPs had higher prevalence of OCT-macrophage (88.0% vs. 52.0%, p=0.01), CAS-red thrombus (88.8% vs. 52.2%, p=0.004) and CAS-low grade-yellow plaque (grade 1) (55.6% vs. 21.7%, p=0.02) than those without. SAP lesions with HPs had higher prevalence of CAS-yellow plaque (35.3% vs. 5.9%, p=0.09) and OCT-thin-cap fibroatheroma (42.1% vs. 5.9%, p=0.04) than SAP without HPs. ACS lesions with HPs had less CAS-red thrombus (0.0% vs. 50.0%, p=0.03) and OCT-plaque rupture (12.5% vs. 66.7%, p=0.04) than ACS without HPs. Multivariate logistic regression analysis revealed that OCT-macrophages (odds ratio (OR): 6.65, 95%-confidence intervals: 1.07–41.5, p=0.043), CAS-red thrombus (OR 8.77, 95% CI 1.33–57.8, p=0.02), and low grade-yellow plaque (OR 13.05, 95% CI 1.97–86.5, p=0.008) were independently related with the existence of HPs lesions. Combination of these 3 factors showed a high predictive value of OCT-HPs lesions (90.9%). Conclusions HPs lesions showed the lower lesion vulnerability than common ACS lesions but had more intraplaque inflammatory condition compared with common SAP lesions. Combined CAS and OCT examination might be useful to clarify the plaque components of HPs lesions in vivo, leading to help us understand the clinical significance of HPs. Funding Acknowledgement Type of funding source: None


2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Takashi Kubo ◽  
Yoshiki Matsuo ◽  
Yasushi Ino ◽  
Takashi Tanimoto ◽  
Kohei Ishibashi ◽  
...  

Background. Recent intravascular ultrasound (IVUS) studies have demonstrated that hypoechoic plaque with deep ultrasound attenuation despite absence of bright calcium is common in acute coronary syndrome. Such “attenuated plaque” may be an IVUS characteristic of unstable lesion.Methods. We used optical coherence tomography (OCT) in 104 patients with unstable angina to compare lesion characteristics between IVUS-detected attenuated plaque and nonattenuated plaque.Results. IVUS-detected attenuated plaque was observed in 41 (39%) patients. OCT-detected lipidic plaque (88% versus 49%, ), thin-cap fibroatheroma (48% versus 16%, ), plaque rupture (44% versus 11%, ), and intracoronary thrombus (54% versus 17%, ) were more often seen in IVUS-detected attenuated plaques compared with nonattenuated plaques.Conclusions. IVUS-detected attenuated plaque has many characteristics of unstable coronary lesion. The presence of attended plaque might be an important marker of lesion instability.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Jun Wang ◽  
Lu Jia ◽  
Xing Li ◽  
Siyu Jin ◽  
Xiaomei Li ◽  
...  

Background. Fibrinogen levels have been associated with coronary plaque vulnerability in experimental studies. However, it has yet to be determined if serum fibrinogen levels are independently associated with coronary plaque vulnerability as detected by optical coherence tomography (OCT) in patients with coronary heart disease. Methods. Patients with coronary heart disease (CHD) who underwent coronary angiography and OCT in our department from January 2015 to August 2018 were included in this study. Coronary lesions were categorized as ruptured plaque, nonruptured with thin-cap fibroatheroma (TCFA), and nonruptured and non-TCFA. Presence of ruptured plaque and nonruptured with TCFA was considered to be vulnerable lesions. Determinants of coronary vulnerability were evaluated by multivariable logistic regression analyses. Results. A total of 154 patients were included in this study; 17 patients had ruptured plaques, 15 had nonruptured plaques with TCFA, and 122 had nonruptured plaques with non-TCFA. Results of univariate analyses showed that being male, diabetes, current smoking, high body mass index (BMI), and clinical diagnosis of acute coronary syndrome (ACS) were associated with coronary vulnerability. No significant differences were detected in patient characteristics, coronary angiographic findings, and OCT results between patients with higher and normal fibrinogen. Results of multivariate logistic analyses showed that diabetes and ACS were associated with TCFA, while diabetes, higher BMI, and ACS were associated with plaque rupture. Conclusions. Diabetes, higher BMI, and ACS are independently associated with coronary vulnerability as detected by OCT. Serum fibrinogen was not associated with coronary vulnerability in our cohort.


2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Jacob S. Lefler ◽  
Joshua D. Higbee ◽  
Richard T. Burnett ◽  
Majid Ezzati ◽  
Nathan C. Coleman ◽  
...  

Abstract Background Cohort studies have documented associations between fine particulate matter air pollution (PM2.5) and mortality risk. However, there remains uncertainty regarding the contribution of co-pollutants and the stability of pollution-mortality associations in models that include multiple air pollutants. Furthermore, it is unclear whether the PM2.5-mortality relationship varies spatially, when exposures are decomposed according to scale of spatial variability, or temporally, when effect estimates are allowed to change between years. Methods A cohort of 635,539 individuals was compiled using public National Health Interview Survey (NHIS) data from 1987 to 2014 and linked with mortality follow-up through 2015. Modelled air pollution exposure estimates for PM2.5, other criteria air pollutants, and spatial decompositions (< 1 km, 1–10 km, 10–100 km, > 100 km) of PM2.5 were assigned at the census-tract level. The NHIS samples were also divided into yearly cohorts for temporally-decomposed analyses. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) in regression models that included up to six criteria pollutants; four spatial decompositions of PM2.5; and two- and five-year lagged mean PM2.5 exposures in the temporally-decomposed cohorts. Meta-analytic fixed-effect estimates were calculated using results from temporally-decomposed analyses and compared with time-independent results using 17- and 28-year exposure windows. Results In multiple-pollutant analyses, PM2.5 demonstrated the most robust pollutant-mortality association. Coarse fraction particulate matter (PM2.5–10) and sulfur dioxide (SO2) were also associated with excess mortality risk. The PM2.5-mortality association was observed across all four spatial scales of PM2.5, with higher but less precisely estimated HRs observed for local (< 1 km) and neighborhood (1–10 km) variations. In temporally-decomposed analyses, the PM2.5-mortality HRs were stable across yearly cohorts. The meta-analytic HR using two-year lagged PM2.5 equaled 1.10 (95% CI 1.07, 1.13) per 10 μg/m3. Comparable results were observed in time-independent analyses using a 17-year (HR 1.13, CI 1.09, 1.16) or 28-year (HR 1.09, CI 1.07, 1.12) exposure window. Conclusions Long-term exposures to PM2.5, PM2.5–10, and SO2 were associated with increased risk of all-cause and cardiopulmonary mortality. Each spatial decomposition of PM2.5 was associated with mortality risk, and PM2.5-mortality associations were consistent over time.


2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Takashi Kubo ◽  
Yasushi Ino ◽  
Takashi Tanimoto ◽  
Hironori Kitabata ◽  
Atsushi Tanaka ◽  
...  

Optical coherence tomography (OCT) is a high-resolution imaging technique that offers microscopic visualization of coronary plaques. The clear and detailed images of OCT generate an intense interest in adopting this technique for both clinical and research purposes. Recent studies have shown that OCT is useful for the assessment of coronary atherosclerotic plaques, in particular the assessment of plaque rupture, erosion, and intracoronary thrombus in patients with acute coronary syndrome. In addition, OCT may enable identifying thin-cap fibroatheroma, the proliferation of vasa vasorum, and the distribution of macrophages surrounding vulnerable plaques. With its ability to view atherosclerotic lesions in vivo with such high resolution, OCT provides cardiologists with the tool they need to better understand the thrombosis-prone vulnerable plaques and acute coronary syndromes. This paper reviews the possibility of OCT for identification of vulnerable plaques in vivo.


2021 ◽  
Vol 5 (6) ◽  
Author(s):  
Isabel Muñoz Pousa ◽  
Ubaldo Hernández ◽  
Victor A Jiménez Díaz

Abstract Background Intracoronary imaging techniques have allowed characterizing atherosclerotic plaques morphologically in patients with the acute coronary syndrome (ACS). Although the main feature described is plaque rupture, the use of optical coherence tomography has made it possible to objectify that the eroded plaque is not uncommon in this setting. Case summary We presented a case of a 45-year-old man with active smoking and cocaine user, admitted to the emergency department for chest pain. The electrocardiogram showed ST-segment elevation myocardial infarction (STEMI) in the inferior leads. Emergent coronary angiography was performed, showing thrombotic occlusion of mid-distal right coronary artery. After successful thromboaspiration, no areas of significant angiographic stenosis were observed. Optical coherence tomography imaging at the occlusion site revealed an eroded plaque and a remaining small thrombusburden. Conservative management without stent implantation was decided. Treatments consisted of an acute phase glycoprotein IIb/IIIa inhibitor and subsequently dual antiplatelet therapy with Aspirin (ASA) and Ticagrelor 90 mg b.i.d. for 12 months. The patient remains asymptomatic and uneventful at 9-month follow-up. Discussion Young age, history of active smoking, and cocaine use are common clinical features in patients with ACS due to an eroded plaque. These patients frequently display a STEMI with the involvement of a single coronary vessel. Optical coherence tomography imaging aids to a precise diagnosis and to define a proper treatment.


Author(s):  
Krishna Prasad ◽  
Sreeniavs Reddy S ◽  
Jaspreet Kaur ◽  
Raghavendra Rao k ◽  
Suraj Kumar ◽  
...  

Introduction: Women perform worse after acute coronary syndrome (ACS) than men. The reason for these differences is unclear. The aim was to ascertain gender differences in the culprit plaque characteristics in ACS. Methods:Patients with ACS undergoing percutaneous coronary intervention for the culprit vessel underwent optical coherence tomography (OCT) imaging. Culprit plaque was identified as lipid rich,fibrous, and calcific plaque. Mechanisms underlying ACS are classified as plaque rupture, erosion,or calcified nodule. A lipid rich plaque along with thin-cap fibroatheroma (TCFA) was a vulnerable plaque. Plaque microstructures including cholesterol crystals, macrophages, and microvessels were noted. Results: A total of 52 patients were enrolled (men=29 and women=23). Baseline demographic features were similar in both the groups except men largely were current smokers (P<0.001). Plaque morphology,men vs. women: lipid rich 88.0% vs. 90.5%; fibrous 4% vs 0%; calcific 8.0% vs. 9.5% (P = 0.64). Of the ACS mechanisms in males versus females; plaque rupture (76.9 % vs. 50 %), plaque erosion (15.4 % vs.40 %) and calcified nodule (7.7 % vs. 10 %) was noted (P = 0.139). Fibrous cap thickness was (50.19 ±11.17 vs. 49.00 ± 10.71 mm, P = 0.71) and thin-cap fibroatheroma (96.2% vs. 95.0%, P = 1.0) in men and women respectively. Likewise no significant difference in presence of macrophages (42.3 % vs. 30%, P = 0.76), microvessels (73.1% vs. 60 %, P = 0.52) and cholesterol crystals (92.3% vs. 80%, P = 0.38). Conclusion: No significant gender-based in-vivo differences could be discerned in ACS patients’ culprit plaques morphology, characteristics, and underlying mechanisms.


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