Coronary Plaque Vulnerability Research Articles

Type D personality and coronary atherosclerotic plaque vulnerability: The potential mediating effect of health behavior

ObjectiveThe association between type D personality and coronary plaque vulnerability has been suggested. The objective of the study was to evaluate the potential mediating effects of health behavior on the association between type D personality and plaque vulnerability in coronary artery disease (CAD) patients. MethodsA total of 319 CAD patients were assessed for type D personality and health behavior via self-administered questionnaires. The plaque vulnerability, evaluated according to characteristics, accompaniment, and outcomes of plaque, was assessed by optical coherence tomography. ResultsRegression analysis showed that type D personality was independently associated with lipid plaque (odds ratio [OR] = 2.387, p = 0.001), thin cap fibroatheroma (TCFA) (OR = 2.366, p = 0.001), rupture (OR = 2.153, p = 0.002), and lipid arc (β = −0.291, p < 0.001). Mediation analyses showed that aspects of health behavior were significant mediators of the relationship between type D personality and plaque vulnerability. Psychological stress mediated the relationship between type D and lipid plaque (p = 0.030), TCFA (p = 0.034), and rupture (p = 0.013). Living habits significantly mediated the relationship between type D and lipid plaque (p = 0.028), TCFA (p = 0.036), but not rupture (p = 0.066). Participating in activities was not a significant mediator of the relationship between type D personality and lipid plaque (p = 0.115), TCFA (p = 0.115), or rupture (p = 0.077). ConclusionsHealth behaviors (psychological stress and living habits) may be mediators of the association between type D personality and plaque vulnerability.

Association between histological features of epicardial adipose tissue and coronary plaque characteristics on computed tomography angiography.

The means by which epicardial adipose tissue (EAT) could influence coronary plaque progression biologically remain unclear. We investigated the association between the histological findings of EAT and coronary plaque characteristics assessed by coronary computed tomography angiography (CCTA). We enrolled 34 patients in whom one or more coronary plaques containing non-calcified components were detected on CCTA before cardiac surgery [coronary artery bypass graft (CABG) or non-CABG]. We evaluated visceral adipose tissue (VAT) area, EAT volume, and coronary plaque characteristics including minimum computed tomography density (CTD) and vascular Remodeling Index (RI). Lower CTD and higher RI were considered as high-risk characteristics, and coronary plaque with both CTD<39 Hounsfield units and RI>1.05 was defined as two-characteristic plaque (2-CP). The numbers of CD68+ macrophages and CD31+ microvessels were assessed in six random high-power fields (400×) of EAT samples obtained during cardiac surgery. The entire cohort showed a wide range of EAT volume, which were similar between patients with 2-CP and those without. Patients with 2-CP had more amounts of EAT macrophages (85±38 versus 45±22, p=0.0005) and vascularity (62±33 versus 37±19, p=0.013) than those without. On multivariate analyses adjusted for age, sex, coronary risk factors, statin use, type of surgery, VAT area, EAT volume, and coronary calcium score, the presence of 2-CP showed significant correlation with increased EAT macrophages (β=0.65, p=0.014) and vascularity (β=0.74, p=0.0053). Our findings support the hypothesis that EAT biologic activities are associated with coronary plaque vulnerability.

Impact of CD14++CD16+ monocytes on coronary plaque vulnerability assessed by optical coherence tomography in coronary artery disease patients

Background and aimsThis study examined the impact of CD14++CD16+ monocytes on coronary plaque vulnerability, as assessed by optical coherence tomography (OCT), and investigated their association with daily glucose fluctuation. Although increased CD14++CD16+ monocyte levels have been reported to increase cardiovascular events, their impact on coronary plaque vulnerability in coronary artery disease (CAD) patients with or without diabetes mellitus (DM) remains unclear. MethodsThis prospective observational study included 50 consecutive patients with CAD, receiving lipid-lowering therapy and undergoing coronary angiography and OCT. Patients were divided into 3 tertiles according to the CD14++CD16+ monocyte percentages assessed by flow cytometry. Standard OCT parameters were assessed for 97 angiographically intermediate lesions (diameter stenosis: 30–70%). Daily glucose fluctuation was analyzed by measuring the mean amplitude of glycemic excursion (MAGE). ResultsCD14++CD16+ monocytes negatively correlated with fibrous cap thickness (r = −0.508, p < 0.01). The presence of thin-cap fibroatheroma (TCFA) was increased stepwise according to the tertile of CD14++CD16+ monocytes (0 [tertile 1] vs. 5 [tertile 2] vs. 10 [tertile 3], p < 0.01). CD14++CD16+ monocytes were a significant determinant of TCFA (OR 1.279, p = 0.001). In non-DM patients, a significant relationship was found between CD14++CD16+ monocytes and MAGE (r = 0.477, p = 0.018). ConclusionsCD14++CD16+ monocytes were associated with coronary plaque vulnerability in CAD patients with well-regulated lipid levels both in DM and non-DM patients. Cross-talk between glucose fluctuation and CD14++CD16+ monocytes may enhance plaque vulnerability, particularly in non-DM patients. CD14++CD16+ monocytes could be a possible therapeutic target for coronary plaque stabilization.

Glycemic variability, but not HbA1c, is associated with high SYNTAX scores at the acute phase of myocardial infarction (AMI) in diabetic patients treated with insulin infusion

In acute myocardial infarction (AMI), high blood glucose at admission is associated with mortality, but randomized trials using intravenous insulin infusions (IVII) have presented conflicting results. In diabetic patients with CAD, glucose variability (GV) is a prognostic factor through progression of non-culprit lesions, coronary plaque vulnerability, and left ventricular remodeling. We aim to identify factors associated with high GV among diabetic patients admitted for AMI and treated with IVII. All consecutive diabetic patients admitted to our University Hospital for AMI between January 2014 and March 2016 and who received IVII were included. Mean amplitude of glycemic excursions (MAGE) was calculated within 2 days after admission, as an index of GV. Among the 1305 AMI admitted, 196 patients were included. Mean age was 71.3 ± 12.1 years, 31% were women, with MAGE at 0.72 ± 0.41. When compared with lower MAGE tertiles, patients from the last tertile were more often women, chronically treated with insulin, with history of renal failure, higher glycemia at admission, HbA 1c levels, SYNTAX and GRACE scores, and lower systolic (SBP) and diastolic (DBP) blood pressures. After multivariate analysis, female (OR (95% CI): 5.67 (2.29–14.02)), HbA 1c (OR (95% CI): 1.77 (1.33–2.34)), SBP (OR (95% CI): 0.99 (0.97–1),) and SYNTAX score (OR (95% CI): 1.05 (1.01–1.08)) were associated with the highest tertile. Moreover, age (OR (95% CI): 1.05 (1.02–1.09)), history of stroke (OR (95% CI): 6.25 (1.65–23.5)) and the highest tertile of MAGE (OR (95% CI): 2.60 (1.24–5.41)) were associated with the highest tertile of SYNTAX score, whereas HbA 1c was not. GV was mainly associated with diabetes-related factors, and was independently associated with a high SYNTAX score. Our findings suggest that assessment of blood GV could contribute to the identification of high-risk diabetics and become a therapeutic target in primary and secondary prevention.

Type 2 diabetes mellitus is associated with a lower fibrous cap thickness but has no impact on calcification morphology: an intracoronary optical coherence tomography study

BackgroundPatients with type 2 diabetes (T2DM) are at high risk for cardiovascular events, which usually arise from the rupture of a vulnerable coronary plaque. The minimal fibrous cap thickness (FCT) overlying a necrotic lipid core is an established predictor for plaque rupture. Recently, coronary calcification has emerged as a relevant feature of plaque vulnerability. However, the impact of T2DM on these morphological plaque parameters is largely unexplored. Therefore, this study aimed to compare differences of coronary plaque morphology in patients with and without T2DM with a particular focus on coronary calcification.MethodsIn 91 patients (T2DM = 56, non-T2DM = 35) with 105 coronary de novo lesions (T2DM = 56, non-T2DM = 49) plaque morphology and calcification were analyzed using optical coherence tomography (OCT) prior to coronary intervention.ResultsPatients with T2DM had a lower minimal FCT (80.4 ± 27.0 µm vs. 106.8 ± 27.8 µm, p < 0.001) and a higher percent area stenosis (77.9 ± 8.1% vs. 71.7 ± 11.2%, p = 0.001) compared to non-diabetic subjects. However, patients with and without T2DM had a similar total number of calcifications (4.0 ± 2.6 vs. 4.2 ± 3.1, p = ns) and no significant difference was detected in the number of micro- (0.34 ± 0.79 vs. 0.31 ± 0.71), spotty (2.11 ± 1.77 vs. 2.37 ± 1.89) or macro-calcifications (1.55 ± 1.13 vs. 1.53 ± 0.71, all p = ns). The mean calcium arc (82.3 ± 44.8° vs. 73.7 ± 31.6), the mean thickness of calcification (0.54 ± 0.13 mm vs. 0.51 ± 0.15 mm), the mean calcified area (0.99 ± 0.72 mm2 vs. 0.78 ± 0.49 mm2), the mean depth of calcification (172 ± 192 μm vs. 160 ± 76 μm) and the cap thickness overlying the calcification (50 ± 71 μm vs. 62 ± 61 μm) did not differ between the diabetic and non-diabetic groups (all p = ns).ConclusionT2DM has an impact on the minimal FCT of the coronary target lesion, but not on localization, size, shape or extent of calcification. Thus, the minimal FCT overlying the necrotic lipid core but not calcification is likely to contribute to the increased plaque vulnerability observed in patients with T2DM.

Automated lipid-rich plaque detection with short wavelength infra-red OCT system.

Vulnerable coronary plaque is characterized by a large lipid core. Although commercially-available optical coherence tomography (OCT) systems use near-infrared light at 1300 nm wavelength, lipid shows characteristic absorption at 1700 nm. Therefore, we developed a novel, short wavelength infra-red, spectroscopic, spectral-domain OCT. The aim of the present study is to evaluate the accuracy of short wavelength (1700 nm) infra-red optical coherence tomography (SWIR-OCT) for identification of lipid tissue within coronary plaques. Twenty-three coronary arteries from 10 cadavers were imaged at physiological pressure with 2.7 Fr SWIR-OCT catheter. When a blood-free image was observed, the SWIR-OCT imaging core was withdrawn at a rate of 20 mm/s using an automatic pullback device. SWIR-OCT images were acquired at 94frames/s and digitally archived. SWIR-OCT generated grey-scale cross sectional images and colour tissue maps of all of the plaque by using a lipid analysis algorithm. After SWIR-OCT imaging, the arteries were pressure-fixed, sliced by cryostat and stained with Oil Red O, and then corresponding histology was collected in matched images. Regions of interest, selected from histology, were 117 lipidic and 34 fibrotic/calcified regions. SWIR-OCT showed high sensitivity (89%) and specificity (92%) for identifying lipid tissue within coronary plaques. The positive predictive value and negative predictive value were 97% and 74%, respectively. SWIR-OCT accurately identified lipid tissue in coronary autopsy specimens. This new technique may hold promise for identifying histopathological features of coronary plaque at risk for rupture.

Comparison of the relationship between multiple parameters of glycemic variability and coronary plaque vulnerability assessed by virtual histology-intravascular ultrasound.

Aims/IntroductionIncreased glycemic variability is an important contributing factor to coronary artery disease. Although various parameters of glycemic variability can be derived by continuous glucose monitoring, the clinical relevance of individual parameters has remained unclear. We have now analyzed the relationship of such parameters to coronary plaque vulnerability.Materials and MethodsThe standard deviation of glucose levels (SD glucose), mean amplitude of glycemic excursions (MAGE), continuous overlapping net glycemic action calculated every 1 h (CONGA‐1) and mean of daily differences (MODD) were calculated from continuous glucose monitoring data for 53 patients hospitalized for percutaneous coronary intervention. The relationship of these parameters to the percentage necrotic core of total plaque volume (%NC) as assessed by virtual histology–intravascular ultrasound (a predictor of coronary plaque rupture) was evaluated.ResultsAll parameters of glycemic variability were significantly correlated with %NC, with correlation coefficients of 0.593, 0.626, 0.318, and 0.388 for log(SD glucose), log(MAGE), CONGA‐1 and log(MODD), respectively. Simple linear regression analysis showed that the coefficients of determination for %NC and either log(SD glucose; 0.352) or log(MAGE; 0.392) were greater than those for %NC and either CONGA‐1 (0.101) or log(MODD; 0.151), whereas the residual sums of squares for the former relationships (1045.1 and 979.5, respectively) were smaller than those for the latter (1449.3 and 1369.6, respectively).ConclusionsThe present data suggest that SD glucose and MAGE are more highly correlated with coronary plaque vulnerability than are CONGA‐1 and MODD, and are thus likely better predictors of coronary artery disease.

Original Research. Transluminal Contrast Attenuation Gradient Is Associated with Coronary Plaque Vulnerability — a Computed Tomography Angiography-based Study

Abstract The aim of this study was to demonstrate that the transluminal contrast attenuation gradient (TAG), a new CT imaging-derived marker of functional significance of a coronary stenosis, is directly associated with the vulnerability degree of atheromatous coronary plaques. Material and methods: This is a prospective study on 21 patients with 30 atheromatous plaques in the coronary arteries, who underwent cardiac computed tomography angiography (CCTA) for assessment of coronary plaques. Results: Twelve plaques were classified as vulnerable (40%) and 18 plaques (60%) as non-vulnerable. Plaques associated with a TAG value above 10 HU exhibited in a significantly higher proportion CCTA markers of plaque vulnerability, as compared to plaques in which the attenuation gradient was below 10 HU. TAG values &gt;10 HU were associated with a higher amount of plaque volume (107.4 ± 91.2 mm3 vs. 56.0 ± 37.5 mm3, p = 0.009), necrotic core (32.5 ± 36.9 mm3 vs. 3.1 ± 3.2 mm3, p = 0.0003), and fibro-fatty tissue (17.7 ± 16.3 mm3 vs. 4.0 ± 2.6 mm3, p = 0.0002), as compared to those lesions with TAG values below 10 HU. Linear regression analysis revealed a significant correlation between TAG values and CCTA features of plaque instability: necrotic core (r = −0.73, p &lt;0.0001), fibrofatty tissue (r = −0.63, p = 0.0002), and plaque volume (r = −0.48, p = 0.006). Conclusions: In patients with coronary artery disease, contrast attenuation gradient along the coronary plaques, determined by CCTA, correlates with CT markers of plaque vulnerability. Vulnerable coronary plaques are associated with a higher functional significance than the stable ones with a similar anatomic profile.

Intracoronary Shear Stress and CT Characteristics of Vulnerable Coronary Plaques

Abstract Vulnerable coronary plaques are associated with a significant risk for rupture, and the ability to detect their characteristic features is of extreme importance, as timely detection of rupture-prone plaques could lead to the appropriate initiation of adequate therapeutic measures and prevent the evolution to an acute coronary event. The most common features of vulnerability in coronary plaques are represented by the presence of low density atheroma, a thin fibrous cap, spotty calcifications, and positive remodeling. However, there is still a huge amount of information to be learned about the role of local forces, represented by the shear stress, on the plaque vulnerability. This clinical update aims to present the most recent advances in the field of knowledge regarding the relation between shear stress and plaque vulnerability, starting from the hypothesis that shear stress significantly correlates with the CT features of plaque vulnerability and can represent a new marker of vulnerability in coronary artery plaques.

Impact of CD14++CD16+ monocytes on plaque vulnerability in diabetic and non-diabetic patients with asymptomatic coronary artery disease: a cross-sectional study

BackgroundPreviously, we have reported that daily glucose fluctuations could affect coronary plaque vulnerability, but the underlying mechanisms remained unclear. This study sought to investigate the impact of CD14++CD16+ monocytes on plaque vulnerability, as assessed by virtual histology intravascular ultrasound (VH-IVUS), as well as their relationship to fluctuating glucose levels in patients with asymptomatic coronary artery disease (CAD).MethodsFifty-one patients with asymptomatic CAD, who were undergoing lipid-lowering therapy and underwent VH-IVUS evaluation for angiographically mild to moderate lesions, were enrolled in the study. Standard VH-IVUS parameters, including the percentage volume of the necrotic core (%NC) within the plaque and the presence of a virtual histology thin-cap fibroatheroma (VH-TCFA), were then evaluated. Additionally, monocyte subsets were assessed by flow cytometry, and daily glucose fluctuations were analyzed by measuring the mean amplitude of glycemic excursion (MAGE).ResultsAmong 82 plaques from 22 diabetes mellitus (DM) patients and 29 non-DM patients, 15 VH-TCFAs were identified. CD14++CD16+ monocyte counts significantly correlated with both %NC and the presence of VH-TCFA (%NC: r = 0.339, p = 0.002; VH-TCFA: p = 0.003). Multivariate logistic regression analysis revealed that CD14++CD16+ monocyte counts were independently associated with VH-TCFA (odds ratio = 1.029, p = 0.004). Furthermore, CD14++CD16+ monocyte counts were significantly correlated with the MAGE score in the non-DM patients (r = 0.544, p = 0.005).ConclusionsCD14++CD16+ monocyte levels are associated with coronary plaque vulnerability and can serve as a biomarker for VH-TCFA in patients with CAD undergoing lipid-lowering therapy. In patients without DM, glucose fluctuations may alter the balance of monocyte subsets.Trial registration UMIN Registry number: UMIN000021228

2225Identification of vulnerable coronary atherosclerotic plaque using molecular 3T CMR imaging with an albumin-binding probe

2225Identification of vulnerable coronary atherosclerotic plaque using molecular 3T CMR imaging with an albumin-binding probe

Detection of the Vulnerable Coronary Atherosclerotic Plaque—Promises and Limitations

The merit of imaging “vulnerable atherosclerotic plaques” remains highly controversial. This review aims at providing current evidence for both its benefit and limitations. Results from optical coherence tomography and intravascular ultrasound imaging in patients with coronary heart disease suggest that certain individual coronary atherosclerotic plaque characteristics, e.g., large lipid core in a fibroatheroma, are associated with greater risk of adverse patient outcome. However, a closer look at these studies reveals that these associations are confounded by the relationship of “vulnerable plaque” characteristics with baseline lumen obstruction, which is a known predictor of recurrent angina and the main component of the reported adverse patient outcome. Recent insights into the pathophysiology of acute coronary syndromes suggest it to be an exceedingly complex process involving numerous local and systemic factors, which hinders outcome prediction. The quest for the vulnerable plaque rests on the erroneous assumption that detecting coronary atherosclerotic lesions, which are prone to rupture or erode, will identify individuals at high risk of suffering acute coronary events. However, there is strong and consistent evidence suggesting that plaques most commonly rupture without associated clinical symptoms. Instead, ruptured plaques typically heal clinically silently and lead to plaque progression. The atherosclerotic disease burden, its metabolic activity, and risk factors for an inadequate response by the coagulation system to plaque disruption, on the other hand, are important predictors of acute coronary event risk and deserve our attention more than individual plaques.

Type D personality, but not Type A behavior pattern, is associated with coronary plaque vulnerability

Personality traits are associated with major adverse coronary events (MACE) in patients with coronary artery disease (CAD). However, the link between personality traits and intravascular morphology in CAD patients is poorly understood. This study investigated the relationship between personality traits, specifically Type A behavior pattern and Type D personality, and plaque vulnerability. After adjustment for demographic and clinical factors, multivariable regression analysis showed no association between Type A and optical coherence tomography indices. However, Type D personality was independently associated with lipid plaque, thin cap fibroatheroma (TCFA), and fibrous cap thickness. More specifically, negative affectivity of Type D was related to lipid plaque, TCFA and fibrous cap thickness, and social inhibition was associated with plaque rupture. Our results show that Type D personality was associated with plaque vulnerability, independent of clinical factors. Measurement of negative affectivity and social inhibition will increase our understanding of the progressive phase of the plaque vulnerability, which can contribute to the early identification of high risk patients and reduce the incidence of MACE.

A Comparative Preliminary Study on CT Contrast Attenuation Gradient Versus Invasive FFR in Patients with Unstable Angina

Abstract The aim of this preliminary study was to assess the effectiveness of transluminal contrast attenuation gradient (TAG) determined by computed tomographic angiography (CTA), for the evaluation of the functional significance of coronary artery stenoses in patients with acute coronary syndromes produced by vulnerable coronary plaques, and to demonstrate the correlation between this new parameter and the vulnerability markers of the culprit lesions. Material and methods: This is a preliminary pilot study on 10 patients with acute coronary syndromes – unstable angina type, who underwent CTA for the assessment of coronary lesions, followed by invasive angiography and the determination of fractional flow reserve (FFR) prior to a revascularization procedure. Patients were divided into 2 groups, according to their FFR values: Group 1 consisted of 6 patients with an FFR value &lt;0.8 (functionally significant lesion), and Group 2 consisted of 4 patients who presented an FFR value &gt;0.8 (functionally non-significant lesion). Results: FFR values were 0.64 ± 0.07, 95% CI: 0.5–0.7 in Group 1, and 0.86 ± 0.05, 95% CI: 0.7–0.9 in Group 2. Plaques associated with an FFR&lt;0.8 presented a higher amount of plaque volume (192.7 ± 199.7 mm3 vs. 42.1 ± 27.3 mm3, p = 0.1), necrotic core (66.7 ± 72.9 mm3 vs. 10.0 ± 9.3 mm3, p = 0.1), and fibro-fatty tissue (29.7 ± 37.4 mm3 vs. 6.2 ± 3.8 mm3, p = 0.2). At the same time, TAG significantly correlated with the presence of a functionally significant lesion. Coronary lesions associated with low FFR presented significantly higher values of TAG along the plaque as compared with lesions with FFR values &gt;0.8 (TAG values 22.1 ± 5.8 HU vs. 11.7 ± 2.5 HU, p = 0.01). Linear regression identified a significant correlation between TAG and FFR values as a measure of functional significance of the lesion (r = 0.7, p = 0.01). Conclusions: Contrast attenuation gradient along the culprit lesion, determined by CTA, correlates with the FFR values and with CT markers of plaque vulnerability, indicating that the presence of vulnerability features inside a coronary plaque could increase the functional significance of a coronary lesion.

Cardiac Computed Tomography Assessment in Acute Coronary Syndromes — Do We Have Time for It in Emergency Settings?

Abstract The diagnosis and treatment of acute coronary syndrome remain a challenge for clinicians in many clinical settings, especially in patients with previous low-to-intermediate risk. Due to its high specificity and sensitivity for detecting significant coronary artery stenoses, cardiac computed tomography angiography (CCTA) tends to be used more frequently in the emergency room (ER) in the last years. This technique has been associated with a higher rate of safe discharge in patients with chest pain, less time spent in the ER, and decreased costs related to further investigations. In cases positive for coronary artery stenosis, CCTA can accurately evaluate the indication for percutaneous coronary angioplasty and can offer relevant information related to the characteristics of the coronary plaques, being able to detect vulnerable coronary plaques. The aim of this manuscript is to highlight the possibility of using CCTA in the ER in the assessment of patients with chest pain and to show the benefits of the procedure regarding safety, costs, accuracy, and time.

The impact of blood pressure variability on coronary plaque vulnerability in stable angina: an analysis using optical coherence tomography.

Blood pressure variability (BPV), especially visit-to-visit BPV, has been reported to be a risk factor for cardiovascular disease. The impact of BPV on coronary plaque vulnerability remains uncertain. The aim of this study was to investigate the relationship between BPV and coronary plaque vulnerability. From August 2013 to May 2014, 36 patients with both hypertension and stable angina pectoris who underwent a percutaneous coronary intervention guided by frequency-domain optical coherence tomography were investigated retrospectively. The size of the lipid cores and the thickness of the fibrous cap covering the lipid core were measured by frequency-domain optical coherence tomography, and we calculated the blood pressure coefficient of variation (CV) and SD as intraindividual visit-to-visit BPV. Both SD and CV of systolic blood pressure (SBP) correlated positively with lipid arc (SBP-SD: r=0.68, P<0.01; SBP-CV: r=0.64, P<0.01) as well as average SBP (r=0.48, P<0.01). Fibrous cap thickness did not correlate with blood pressure variables or BPV. BPV is related to coronary plaque volume, but not to coronary plaque vulnerability. In addition to conventional coronary risk factors, BPV may be a therapeutic target for coronary atherosclerosis.

Early Detection and Treatment of the Vulnerable Coronary Plaque: Can We Prevent Acute Coronary Syndromes?

Early identification and treatment of the vulnerable plaque, that is, a coronary artery lesion with a high likelihood of rupture leading to an acute coronary syndrome, have gained great interest in the cardiovascular research field. Postmortem studies have identified clear morphological characteristics associated with plaque rupture. Recent advances in invasive and noninvasive coronary imaging techniques have empowered the clinician to identify suspected vulnerable plaques in vivo and paved the way for the evaluation of therapeutic agents targeted at reducing plaque vulnerability. Local treatment of vulnerable plaques by percutaneous coronary intervention and systemic treatment with anti-inflammatory and low-density lipoprotein-lowering drugs are currently being investigated in large randomized clinical trials to assess their therapeutic potential for reducing adverse coronary events. Results from these studies may enable a more patient-tailored strategy for the treatment of coronary artery disease.

Patients with vulnerable coronary plaques have higher serum metalloproteinase-1 levels

Most acute coronary syndromes are caused by the fracture of a vulnerable atherosclerotic plaque. These plaques are thin cap fibroatheromas, which can only be detected with invasive coronary imaging techniques. It is necessary to find a non-invasive biomarker of these vulnerable plaques in order to identify patients at risk without a coronary angiography. Metalloproteinase-1 is an enzyme involved in extracellular matrix metabolism which has been correlated with the rupture of atherosclerotic plaques. Its serum levels in patients with vulnerable plaques remain unknown. Patients with suspected stable coronary artery disease undergoing coronary angiography in our hospital were in-cluded. The coronary arteries were studied with optical coherence tomography to detect vulnerable plaques. Blood samples were taken from a peripheral vein and from the coronary sinus, to assess metalloproteinase-1 levels. Fifty-one patients were included, 13 of whom had at least one vulnerable plaque. There were not significant dif-ferences in clinical characteristics, lipid profile or C reactive protein levels, between patients with or without vulnerable plaques. Patients with vulnerable plaques had significant higher metalloproteinase-1 levels both in peripheral (7330±5541 vs 2894±1783 pg/ml, p=0.025) and coronary sinus serum (6012±3854 vs 2707±1252 pg/ml, p=0.047). Patients with vulnerable plaques had significantly higher metalloproteinase-1 serum levels. Further studies with clinical follow up are needed to assess the prognostic value of serum metalloproteinase-1.

Echolucency of the carotid artery is associated with short-term plaque progression and positive remodeling in the culprit coronary artery in AMI survivors

BackgroundRapid plaque progression and positive remodeling are recognized as vulnerable coronary plaque characteristics. This study examined whether serial carotid ultrasonography might be of value for assessment of coronary plaque progression and positive remodeling, measured by serial intravascular ultrasound (IVUS), in survivors of acute myocardial infarction (AMI). MethodsThirty-nine patients with AMI had repeated examinations by IVUS of culprit coronary arteries and echolucency of the coronary artery on admission (1st test) and 6 months later (2nd test). Plaque volume and external elastic membrane area of the native segment (15±9mm in length) beginning 5mm proximal to the stent edge in the culprit coronary artery were measured using volumetric IVUS. Echolucency of the carotid artery was assessed by integrated backscatter (IBS) analysis. Lower IBS reflects an echolucent and lipid-rich plaque. ResultsIncrease in coronary plaque volume and positive remodeling over 6 months occurred in 17 and 12 patients, respectively. The % change in carotid IBS value over 6 months was correlated with the % change in the coronary plaque volume (r=−0.69, p<0.001). The aggravated change in the carotid IBS was significantly associated with increase in the coronary plaque volume and positive remodeling over 6 months (OR 0.94 and 0.95, respectively, 95% CI 0.90–0.99, both p<0.05). ConclusionsSerial measurements of echolucency of the carotid artery may be of value for assessment of short-term progression and positive remodeling of coronary plaques in AMI survivors.

Positive Remodeling as a Biomarker of Plaque Vulnerability — at the Border Between Invasive and Noninvasive Assessment

AbstractSince the introduction of the new concepts of plaque vulnerability and patient vulnerability, many researchers have focused on different biomarkers that can represent predictors for coronary plaque instability. One of the features that characterize the vulnerable coronary plaque is positive remodeling, which can be easily identified by computed tomography angiography, a noninvasive procedure, or by other invasive methods such as intravascular ultrasound. This review aims to describe the assessment of positive remodeling as a marker of coronary plaque instability and the differences between computed tomography angiography and intravascular ultrasound in investigating this new biomarker.