Positive Remodeling Index Research Articles

High-risk coronary plaque of sudden cardiac death victims: postmortem CT angiographic features and histopathologic findings

High-risk coronary plaques (HRP) are characterized in clinical radiological imaging by the presence of low plaque attenuation, a napkin-ring sign (NRS), spotty calcifications (SC) and a positive remodeling index (RI). To evaluate if these signs are detectable in postmortem imaging by a multi-phase postmortem CT angiography (MPMCTA), a retrospective study of a series of autopsy well-documented coronary plaques related to sudden cardiac death (SCD) was performed. Then correlations between histological and radiological findings were described. Fourty SCD cases due to acute coronary syndrome based on clinical history and confirmed at autopsy were selected (28 men and 12 women, age 53.3 ± 10.9). The culprit lesion was mainly situated in the proximal segments of coronary arteries, in the right coronary artery in 23 cases (57.5%), the left anterior descending artery in 13 cases (32.5%), the circumflex artery in 3 cases (7.5%) and in one case in the left main stem. MPMCTA showed a positive RI (≥ 1.1) in 75% of cases with a mean RI 1.39 ± 0.71. RI values were lower in cases with fibrotic plaques. NRS was observed in 40% of cases, low attenuation plaque in 46.3%, and SC in 48.7% of cases. There were significant correlations of the radiological presence of NRS for fibrolipid composition of the plaque (p-value 0.007), severe intraplaque inflammation (p-value 0.017), severe adventitial inflammation (p-value 0.021) and an increased vasa vasorum (p-value 0.012). A significant correlation (p-value 0.002) was observed between the presence of SC at radiological examination and the presence of punctuate/fragmented calcification at histology. In addition, in 58.3% of cases, plaque enhancement was observed, which correlated with plaque inflammation and the fibrolipid composition of the plaque. The coronary artery calcium score was 314 (± 455). There was a poor agreement between stenosis of the lumen at histology versus radiology. Our study shows that the various radiological signs of HRP can be detected in all plaques by MPMCTA, but individually only to a variable extent; plaque enhancement appeared as a new sign of vulnerability. In the postmortem approach, these radiological markers of HRP, should always be applied in combination, which can be useful for developing a predictive model for diagnosing coronary SCD.

CT Coronary Angiography: Technical Approach and Atherosclerotic Plaque Characterization.

Coronary computed tomography angiography (CCTA) currently represents a robust imaging technique for the detection, quantification and characterization of coronary atherosclerosis. However, CCTA remains a challenging task requiring both high spatial and temporal resolution to provide motion-free images of the coronary arteries. Several CCTA features, such as low attenuation, positive remodeling, spotty calcification, napkin-ring and high pericoronary fat attenuation index have been proved as associated to high-risk plaques. This review aims to explore the role of CCTA in the characterization of high-risk atherosclerotic plaque and the recent advancements in CCTA technologies with a focus on radiomics plaque analysis.

Cardiac Computed Tomography Angiography in CAD Risk Stratification and Revascularization Planning.

Functional stress testing is frequently used to assess for coronary artery disease (CAD) in symptomatic, stable patients with low to intermediate pretest probability. However, patients with highly vulnerable plaque may have preserved luminal patency and, consequently, a falsely negative stress test. Cardiac computed tomography angiography (CCTA) has emerged at the forefront of primary prevention screening and has excellent agency in ruling out obstructive CAD with high negative predictive value while simultaneously characterizing nonobstructive plaque for high-risk features, which invariably alters risk-stratification and pre-procedural decision making. We review the literature detailing the utility of CCTA in its ability to risk-stratify patients with CAD based on calcium scoring as well as high-risk phenotypic features and to qualify the functional significance of stenotic lesions. Calcium scores ≥ 100 should prompt consideration of statin and aspirin therapy. Spotty calcifications < 3 mm, increased non-calcified plaque > 4 mm3 per mm of the vessel wall, low attenuation < 30 HU soft plaque and necrotic core with a rim of higher attenuation < 130 HU, and a positive remodeling index ratio > 1.1 all confer additive risk for acute plaque rupture when present. Elevations in the perivascular fat attenuation index > -70.1 HU are a strong predictor of all-cause mortality and can further the risk stratification of patients in the setting of a non-to-minimal plaque burden. Lastly, a CT-derived fractional flow reserve (FFRCT) < 0.75 or values from 0.76 to 0.80 in conjunction with additional risk factors is suggestive of flow-limiting disease that would benefit from invasive testing. The wealth of information available through CCTA can allow clinicians to risk-stratify patients at elevated risk for an acute ischemic event and engage in advanced revascularization planning.

Model development and validation of noninvasive parameters based on coronary computed tomography angiography to predict culprit lesions in acute coronary syndromes within 3 years: value of plaque characteristics, hemodynamics and pericoronary adipose tissue.

Machine learning (ML) is combined with noninvasive parameters from coronary computed tomography angiography (CTA) to construct predictive models to identify culprit lesions that may lead to acute coronary syndrome (ACS). We retrospectively analyzed 132 patients with ACS at the Fourth Affiliated Hospital of Harbin Medical University who had coronary CTA between 3 months and 3 years before the ACS event, with a total of 240 lesions. Lesions from 2020 (n=154) were included in the training set, and lesions from 2021 (n=86) were included in the test set for internal validation. We evaluated the role of plaque characteristics, hemodynamic parameters and pericoronary adipose tissue (PCAT) attenuation from CTA in identifying culprit ACS lesions. In the training set, logistic regression was used to screen CTA-derived parameters with P values <0.05 for the model construction. Logistic regression, random forest, Bayesian and K-nearest neighbor algorithms were used to build classification models, and their performance was assessed using the test set. The following models were established to evaluate the effectiveness of different combinations of models to identify culprit lesions: Model 1 was established for plaque characteristics; Model 2 was established for hemodynamic parameters; Model 3 was established for PCAT attenuation; Model 4 was established for plaque characteristics and hemodynamic parameters; and Model 5 was established for plaque characteristics, hemodynamic parameters and PCAT attenuation. A total of ten high-risk factors were screened for the ML model construction, and the ML model based on the logistic regression algorithm had the best performance among the four algorithms (accuracy =0.721; sensitivity =0.892; specificity =0.592; positive prediction =0.623; and negative prediction =0.879). In this model, the minimum lumen area, positive remodeling and lesion-specific fat attenuation index (FAI) were the risk factors significantly associated with the culprit lesion. Analysis of the effect of different combinations of models to identify culprit lesions showed that Model 5 had the best predictive effect (AUC =0.819 and 95% CI: 0.722-0.916). ACS can be predicted using ML based on CTA parameters. Compared to other models, the model combining plaque characteristics, hemodynamic parameters and PCAT attenuation performed best in predicting the culprit lesion.

Abstract 11478: Epicardial Adipose Tissue Volume - Relationship with Coronary Artery Plaque Vulnerability and Myocardial Ischemia in Non-Obstructive Coronary Artery Disease

Introduction: Myocardial ischemia is common among patients with chest pain and non-obstructive coronary artery disease (CAD). Epicardial adipose tissue (EAT) accumulation has been associated with inflammation, atherosclerosis and microvascular dysfunction. Accordingly, we hypothesised that EAT volume is associated with coronary plaque vulnerability and myocardial ischemia in patients with non-obstructive CAD. Methods: We included 125 patients with chest pain and non-obstructive CAD by coronary computed tomography angiography (CCTA). EAT volume was quantified on non-contrast cardiac computed tomography images by a semiautomatic analysis software. CCTA images were analysed with respect to plaque volume and composition. Plaque vulnerability was assessed as total coronary non-calcified plaque volume and positive remodelling index &gt;1.10. Myocardial ischemia was detected by contrast dobutamine stress echocardiography. Patients were grouped in tertiles of EAT volume and high EAT volume was defined as volumes in the highest tertile (≥125 ml). Results: In the total study population (median age 63(58, 69) years and 58% women), the median EAT volume was 104 (77, 141) ml. High EAT volume was more common in men and associated with higher BMI, hypertension and positive remodelling (all p&lt;0.05). There was no difference in age, prevalence of diabetes, total non-calcified plaque volume or presence of myocardial ischemia between groups (all p≥0.34). This was confirmed in univariable logistic regression analyses (Table). After adjusting for covariables in a multivariable model, the association between positive remodelling and high EAT volume was attenuated (Table). Conclusion: High EAT volume was associated with positive remodelling, but not with total non-calcified plaque volume or myocardial ischemia, and the association was attenuated after multivariable adjustments.

Characteristics of symptomatic plaque on high-resolution magnetic resonance imaging and its relationship with the occurrence and recurrence of ischemic stroke.

Atherosclerosis is the most common cause of ischemia stroke. Computed tomographic angiography (CTA) and digital subtraction angiography (DSA) are used to evaluate the degree of lumen stenosis. However, these examinations are invasive and can only reveal mild to moderate stenosis. High-resolution magnetic resonance imaging (HRMRI) seems a more intuitive way to show the pathological changes of vascular wall. Hence, we conducted a systematic retrospective study to determine the characteristics of symptomatic plaques in patients with intracranial atherosclerosis on HRMRI and their association with the occurrence and recurrence of ischemic stroke events. The PubMed database was searched for relevant studies reported from January 31, 2010, to October 31, 2020. We selected 14 clinical outcome studies. We found that plaque enhancement and positive remodeling on HRMRI indicate symptomatic plaques. Besides, intraplaque hemorrhage and positive remodeling index are closely related to the occurrence of stroke. However, it is still controversial whether the initial enhancement of plaque and the occurrence and recurrence of stroke are related. There is also no significant correlation between vascular stenosis and symptomatic plaque or the occurrence and recurrence of ischemic stroke. High-resolution magnetic resonance imaging can be used as an assessment tool to predict the risk of stroke onset and recurrence in patients with atherosclerosis, but further research is also needed.

High-risk coronary plaque in SLE: low-attenuation non-calcified coronary plaque and positive remodelling index

BackgroundPositive remodelling index and presence of low-attenuation non-calcified plaque (LANCP) are characteristic vessel changes in unstable coronary plaques. We sought to characterise these high-risk plaque features in patients with systemic...

Ambient air pollution, traffic proximity and coronary atherosclerotic phenotype in China

BackgroundExposure to ambient air pollution is associated with cardiovascular risk, potentially via atherosclerosis promotion. The disease mechanisms underlying these associations remain uncertain. ObjectivesWe aim to investigate the relationship of air pollution and traffic proximity with subclinical atherosclerosis, using coronary plaque phenotypes to gain insight into potential mechanisms. MethodsCoronary plaque total and component volumes, high-risk plaque (HRP) appearance, and luminal stenosis were characterized by coronary computed tomography angiography in 2279 patients with atherosclerosis at baseline between 2014 and 2017. Annual average exposure to air pollutants including fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3) was estimated by air pollution models for individual participants. Multiple linear regression models were used to assess the association of each exposure with plaque phenotypes and coronary stenosis, controlling for potential confounders. Multiple logistic regression models were used to estimate associations with plaque vulnerability. ResultsThe studied population was 60.2±9.2 years old. PM2.5 and NO2 concentrations were significantly associated with a 5.0% (95%CI: 0.3, 9.9%, per 15 μg/m3 increase for PM2.5), 12.0% (95%CI: 2.5, 22.5% per 20 μg/m3 for NO2) larger volume of non-calcified plaque, respectively. Increase in O3 concentration was associated with a 12.2% (95%CI: 2.2, 23.2%, per 5 μg/m3 O3) larger volume of calcified plaque and a 12.8% (95%CI: 0.9, 26.2%) greater lumen narrowing. Increased PM2.5 and NO2, was also associated with increase in HRP, determined by the napkin ring sign (odds ratio: 1.41 [95%CI: 1.10, 1.80] for PM2.5 and 1.78 [95%CI: 1.20, 2.63] for NO2) and positive remodeling index (OR: 1.11 [95%CI: 1.01, 1.21] for PM2.5 and 1.20 [95%CI: 1.02, 1.42] for NO2), respectively, indicating increased plaque vulnerability. ConclusionLong-term exposures to air pollution were associated with greater plaque volume and luminal stenosis, and increased plaque vulnerability with attendant risk of plaque rupture and erosion.

Coronary plaque redistribution after stent implantation is determined by lipid composition: A NIRS-IVUS analysis.

The composition of plaque impacts the results of stenting. The following study evaluated plaque redistribution related to stent implantation using combined near-infrared spectroscopy and intravascular ultrasound (NIRS-IVUS) imaging. The present study included 49 patients (mean age 66 ± 11 years, 75% males) presenting with non-ST elevation myocardial infarction (8%), unstable angina (49%) and stable coronary artery disease (43%). The following parameters were analyzed: mean plaque volume (MPV, mm3), plaque burden (PB, %), remodeling index (RI), and maximal lipid core burden index in a 4 mm segment (maxLCBI4mm). High-lipid burden lesions (HLB) were defined as by maxLCBI4mm > 265 with positive RI. Otherwise plaques were defined as low-lipid burden lesions (LLB). Measurements were done in the target lesion and in 4 mm edges of the stent before and after stent implantation. MPV and maxLCBI4mm decreased in both HLB (MPV 144.70 [80.47, 274.25] vs. 97.60 [56.82, 223.45]; maxLCBI4mm: 564.11 ± 166.82 vs. 258.11 ± 234.24, p = 0.004) and LLB (MPV: 124.50 [68.00, 186.20] vs. 101.10 [67.87, 165.95]; maxLCBI4mm: 339.07 ± 268.22 vs. 124.60 ± 160.96, p < 0.001), but MPV decrease was greater in HLB (28.00 [22.60, 57.10] vs. 13.50 [1.50, 28.84], p = 0.019). Only at the proximal stent edge of LLB, maxLCBI4mm decreased (34 [0, 207] vs. 0 [0, 45], p = 0.049) and plaque burden increased (45.48 [40.34, 51.55] vs. 51.75 [47.48, 55.76], p = 0.030). NIRS-IVUS defined HLB characterized more significant decreases in plaque volume by stenting. Plaque redistribution to the proximal edge of the implanted stent occurred only in LLB.

Relationships between myocardial perfusion abnormalities and integrated indices of atherosclerotic burden: clinical impact of combined anatomic-functional evaluation

Aim to evaluate the relationships between functional and anatomical information obtained by myocardial perfusion imaging (MPI) and coronary computed tomography angiography (CCTA) in a series of consecutive patients at intermediate probability of coronary artery disease (CAD). Material and Methods — The study group comprised 139 patients (83 men, age of 61.6±7.5 years) who underwent CCTA and single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI). Based on CCTA results patients were divided into three groups: 1) with the absence of coronary atherosclerosis on CCTA; 2) with non-obstructive CAD (&lt;50%); 3) with obstructive (≥50%) CAD. The Segment Involvement Score, Segment Stenosis Score (SSS) and CTA Risk Score were calculated as measures of global atherosclerosis burden. MPI studies were considered abnormal in the presence of SSS≥4. Results — Abnormal myocardial perfusion was detected in 60% of cases in group 1 and 2; in 75% of cases in group 3. The overall frequencies of normal and abnormal MPI studies differed significantly only in obstructive CAD patients and did not differ in group 1 and 2. There were no significant correlations between calcium score, atherosclerotic lesion length, positive remodelling index and MPI results in patients with non-obstructive as well as in patients with obstructive CAD. In group of patients with obstructive CAD Segment Stenosis Score correlated wekly with SSS (r=0.39, p=0.001) and SDS (r=0.28; p=0.012); the CTA Risk Score showed correlationes with SSS (r=0.38, p=0.002) and SDS (r=0.30, p=0.020). Conclusion — Myocardial perfusion abnormalities may develop even in the absence of critical coronary artery lesions. The extent of myocardial ischemia correlates with measures of global CAD burden only in patients with obstructive CAD.

P3596The role of MSCT and SPECT in patients with acute coronary syndromes and non-obstructive coronary artery disease

Abstract Background Approximately 1–14% of patients with ACS not have obstructive changes in the coronary arteries according to the data of invasive coronary angiography (ICA) is myocardial infarction (AMI) with non-obstructive coronary artery- MINOCA. MSCT has the ability to assess the lumen of the vessel, visualize the artery wall, the structure of the atherosclerotic plaque. SPECT is used to detect myocardial ischemia, determine the functional significance of atherosclerotic plaques, and evaluate regional tissue perfusion. There are no data on a research of a structurally functional condition of a coronary blood-groove by means of MSCT, SPECT.Aim. To study the role of MSCT and SPECT in patients with MINOCA, to compare MSCT with invasive coronarography. Material and methods The study is registered on ClinicalTrials.gov. Inclusion criteria are listed on the site. All patients underwent CT, SPECT, on the 6th day from the beginning of the index event. All MSCT and SPECT studies were performed on a 64-section combined single-photon-emission and X-ray computer tomograph GE Discovery NM/CT 570C. Endpoint: Frequency of occurrence of atherosclerosis, frequency of occurrence of unstable plaques according to MSCT, the magnitude of a transient defect in myocardial perfusion according to SPECT. Results The study included 14 patients with MINOCA, women predominate – 11 (78.6%), the average age was 61.1±14 years. The risk of GRACE was moderate in 8 (57%) pts. 12 (85.7%) pts were hospitalized within the first 6 hours of the onset of the disease.Thrombolytic therapy was performed in 3 (21.4%) pts, 2 of them were effective (14%). 57% of patients at admission were troponin-positive.According to the results of ICA, intact coronary arteries were detected in 9 (64.3%) pts, 5 (35%) had stenosis up to 50%. Coronary slow flow (TIMI 2) was determined in 11 (78.6%) pts, of which 8 (57%) pts have coronary slow flow and intact coronary arteries. Coronary spasm was in 1 (7.1%) patient. According to MSCT, the proportion of pts with intact coronary arteries decreased (9 (64.3%) → 5 (35.7%)) and the proportion with non-obstructive atherosclerosis increased (5 (35%) → 9 (64.3%)). All pts had a positive remodeling index, soft-tissue, predominantly calcified stenoses and eccentric plaques. The average Segment Involvement Score was 2.1 (0; 5), the Segment Stenosis Score was −2.4 (1; 3). 12 pts (85%) had transitory perfusion defects. The median SSS values were 7.5 (4; 13), SRS 4.7 (1.0; 9.0), SDS 4.7 (3.0; 8.0). Conclusion In 78% of pts had a slowing of the coronary blood flow and intact coronary arteries according to ICAG. However, according to MSCT, only 36% of the patients did not have plaques. MSCT allows to identify eccentric soft tissue atherosclerotic plaques that have a high risk of rupture/erosion, and, accordingly, the high risk of the development of AMI in this group. Using SPECT revealed a statistically significant transient perfusion defect.

Sodium-fluoride PET-CT for the non-invasive evaluation of coronary plaques in symptomatic patients with coronary artery disease: a cross-correlation study with intravascular ultrasound

ObjectivesThe aim of this study was to evaluate the 18F-sodium fluoride (18F-NaF) coronary uptake compared to coronary intravascular ultrasound (IVUS) in patients with symptomatic coronary artery disease.Background18F-NaF PET enables the assessment of vascular osteogenesis by interaction with surface hydroxyapatite, while IVUS enables both identification and quantification of intra-plaque components.MethodsForty-four patients with symptomatic coronary artery disease were included in this prospective controlled trial, 32 of them (30 patients with unstable angina and 2 patients with stable angina), representing the final study cohort, got additional IVUS. All patients underwent cardiac 18F-NaF PET/CT and IVUS within 2 days. 18F-NaF maximum tissue-to-blood ratios (TBRmax) were calculated for 69 coronary plaques and correlated with IVUS plaque classification.ResultsSignificantly increased 18F-NaF uptake ratios were observed in fibrocalcific lesions (meanTBRmax = 1.42 ± 0.28), thin-cap atheroma with spotty calcifications (meanTBRmax = 1.32 ± 0.23), and thick-cap mixed atheroma (meanTBRmax = 1.28 ± 0.38), while fibrotic plaques showed no increased uptake (meanTBRmax = 0.96 ± 0.18). The 18F-NaF uptake ratio was consistently higher in atherosclerotic lesions with severe calcification (meanTBRmax = 1.34 ± 0.22). The regional 18F-NaF uptake was most likely localized in the border region of intensive calcification. Coronary lesions with positive 18F-NaF uptake showed some increased high-risk anatomical features on IVUS in comparison to 18F-NaF negative plaques. It included a significant severe plaque burden (70.1 ± 13.8 vs. 61.0 ± 13.8, p = 0.01) and positive remodeling index (1.03 ± 0.08 vs. 0.99 ± 0.07, p = 0.05), as well as a higher percentage of necrotic tissue (37.6 ± 13.3 vs. 29.3 ± 15.7, p = 0.02) in positive 18F-NaF lesions.Conclusions18F-NaF coronary uptake may provide a molecular insight for the characterization of coronary atherosclerotic lesions. Specific regional uptake is needed to be determined by histology.

High-Risk Coronary Plaques Complicated with Acute Coronary Syndrome in Young Patients

Abstract Coronary computed tomography angiography (CCTA) has evolved notably over the last decade, gaining an increased amount of temporo-spatial resolution in combination with decreased radiation exposure. The importance of CCTA is emerging especially in vulnerable and young patients who might not have developed a viable collateral vascular network to sustain the circulation to an infarction area during a major adverse coronary event. There are a few well-known markers by which a vulnerable plaque can be assessed and that can predict the subsequent events of sudden myocardial ischemia, such as an increased positive remodeling index (cut-off &gt;1.4), low-attenuation plaque (cut-off &lt;30 HU), plaque burden (cut-off &gt;0.7), and napkin-ring sign (NRS). This manuscript presents a series of 3 clinical cases of young patients experiencing symptoms and signs of myocardial ischemia who underwent CCTA in order to assess the composition and functional characteristics of atherosclerotic plaques and their repercussion in developing an acute coronary syndrome.

Abstract 12608: Coronary Artery Plaque Burden Characterization in Psoriasis Reveals Increase in High Risk Plaque

Introduction: Psoriasis (PSO), a chronic inflammatory skin disease associated with increased risk of MI, provides an ideal translational human model to study inflammatory atherogenesis. The presence of high-risk plaque (HRP) by coronary-computed tomography angiography (CCTA) is associated with prospective CV events. To date, however, no study has characterized HRP morphology in PSO. Hypothesis: We hypothesized that PSO would associate with an increased prevalence of HRP, as compared to controls (HC). Methods: PSO (n=107), HC (n=25), and hyperlipidemic patients (HLD) (n=30) who were candidates for statin therapy under NCEP ATP III guidelines, underwent CCTA (Toshiba, 320-detector row) for coronary plaque characterization. Total and non-calcified plaque burden were quantified using QAngio (Medis). To characterize HRP, a single reviewer evaluated for positive remodeling index (&gt; 1.1), low-attenuation (&lt; 30 HU), and spotty calcification. Statistical analysis included multivariable regression. Results: PSO patients were middle-aged, male-predominant, and at low Framingham risk (Table). Non-calcified plaque burden was higher in PSO than in HC (p =0.05) and in HLD (p = 0.02). The prevalence of HRP was greater in PSO than in HC (34% vs. 8%, p=0.01), and was comparable to that seen in HLD (34% vs. 37%, p=0.78). Logistic regression revealed a significant association between PSO and the presence of HRP, beyond Framingham risk, BMI, glucose, and statins (OR 5.8, p= 0.03). This association, however, attenuated in HLD after adjustment (OR 2.6, p = 0.3). Conclusions: PSO associated with a higher prevalence of HRP, independent of traditional CV risk, and similar to that observed in HLD. These findings are consistent with the known association between PSO and MI, and may lend insight to the residual CV risk not captured by traditional methods in PSO. Larger studies are needed to confirm these results.

Abstract 20008: Echoing Plaque Activity of Coronary Artery With Intracranial Artery in Acute Ischemic Stroke Patients: Coronary CT Angiography and High-resolution MR Imaging Study

Background: Atherosclerosis is a systemic disease, and both coronary and intracranial atherosclerosis are common in elderly. Unlikely to coronary artery disease (CAD), intracranial atherosclerotic disease (ICAD) can cause stroke by branch occlusive disease-type (B-type ICAS), subcortical infarcts caused by parent arterial disease occluding perforator’s orifice as well as coronary type rupture of plaque (C-type ICAS).Vascular pathophysiology of coronary atherosclerosis in relationship with different phenotypes of intracranial atherosclerosis is unknown. Methods: We prospectively recruited 69 patients with acute cerebral infarcts caused by ICAS who had no history of CAD. Patients underwent both cardiac multidetector computed tomography (MDTC) and brain high-resolution MRI (HR-MRI). Symptomatic steno-occlusive intracranial artery at the maximal stenosis on MRA was analyzed in terms of vascular morphology (stenosis degree, remodeling index, and wall index) and activation (enhancement pattern and volume) using HR-MRI. Asymptomatic CAD burden (number and degree of stenosis) and plaque characteristics (calcified, mixed, and non-calcified) were measured with MDCT. The degree of asymptomatic ICAD was also measured in each patient (number of stenotic arteries and degree of stenosis). Results: The mean age of the patients were 65.1±1.5 years, 59.4% were male, and 35 (51.7%) were diagnosed with C-type ICAS. Asymptomatic CAD was observed in most patients, and increase in CAD burden was associated with increased asymptomatic ICAD (p&lt;0.01). Overall CAD burden were not different between B-type and C-type ICAS. However, prevalence of non-calcified coronary plaque were much higher in C-type ICAS (35.3% vs 62.9%, p=0.02). C-type ICAS group also showed higher degree of stenosis (40.4 ±34.5 vs 77.3±17.3, p&lt;0.001), increased positive remodeling index (1.0±0.3 vs 1.3±0.5, p=0.03), and larger proportion of vessels with enhancement (73.5% vs 97.1%, p&lt;0.01) in cerebral arteries compared to B-type ICAS. Conclusions: Plaque characteristics of intracranial and coronary behave in same way. Further studies are needed to find systemic factors associated both intracranial and coronary plaque progression.

Differential association of visceral adipose tissue with coronary plaque characteristics in patients with and without diabetes mellitus

BackgroundExcess visceral adipose tissue (VAT) is closely associated with the presence of coronary artery plaques that are vulnerable to rupture. Patients with diabetes mellitus (DM) have more VAT than patients without DM, but the extent to which VAT contributes to the characteristics of coronary plaques before and after the development of DM is not fully understood.MethodsWe retrospectively evaluated 456 patients (60% male, age 64 ± 16 years) who were suspected to have cardiovascular disease and underwent 64-slice computed tomography angiography (CTA). Seventy-one (16%) patients had vulnerable plaques (CT density < 50 Hounsfield Units, positive remodeling index > 1.05, and adjacent spotty areas of calcification).ResultsPatients were divided into tertiles according to the VAT area. There were stepwise increases in noncalcified and vulnerable plaques with increasing tertiles of VAT area in patients without DM, but not in patients with DM. Multivariate analysis showed that a larger VAT area was significantly associated with a higher risk of vulnerable plaque in patients without DM (odds ratio 3.17, 95% confidence interval 1.08–9.31, p = 0.04), but not in patients with DM.ConclusionsThe VAT area is associated with the characteristics of coronary plaques on CTA in patients without DM, but not in patients with DM. VAT may be a significant cardiometabolic risk factor that is associated with plaque vulnerability before the development of DM. CTA findings may help to improve risk stratification in such patients.

Periprocedural myocardial damage during percutaneous coronary intervention: a point-of-care platelet testing and intravascular ultrasound/virtual histology study

Recent studies have implied that platelet reactivity as well as certain lesion morphology may be linked to myocardial injury during percutaneous coronary intervention (PCI). However, to date the abovementioned features have not been investigated simultaneously in one population. To determine if and how high on-treatment platelet reactivity, different lesion morphology, and plaque components are associated with increased risk of periprocedural myocardial injury in patients referred for elective coronary stenting. Sixty patients pretreated with aspirin and clopidogrel and undergoing elective PCI with stent(s) implantation were included. On-treatment platelet reactivity was measured with VerifyNow Aspirin and P₂Y₁₂ assays (Accumetrics, USA) before PCI. Grey-scale intravascular ultrasound (IVUS) and virtual histology were performed before stent(s) implantation (Volcano, USA). Two levels of myocardial injury were considered: any elevation of troponin I (periprocedural myocardial damage, PMD) and/or > 3 times the upper normal limit (periprocedural myocardial infarction, PMI). By receiver-operating characteristics analysis, the following factors, ranked from strongest to weakest, were able to distinguish between patients with and without PMD: remodelling index (RI), fibrous tissue, fibro-fatty tissue volume (FFT), plaque and media cross-sectional area, and external elastic membrane cross-sectional area (EEM CSA). Only platelet count and RI could differentiate patients with and without PMI. PMD as well as PMI could not be predicted either by VerifyNow Aspirin or P₂Y₁₂ assay. Likewise, there was no association between necrotic core volume and PMD or PMI. In logistic regression analysis, after adjusting for possible clinical and procedural confounding factors, only EEM CSA > 14.6 mm² (OR 23.7, 95% CI 1.9-302, p = 0.015), RI > 1.044 (OR 12.3, 95% CI 1.2-121.9, p = 0.032) and FFT > 11.2 mm³ (OR 13.6, 95% CI 1.1-160.9, p = 0.038) were independent predictors of PMD. Only RI > 1.044 was identified as an independent predictor of PMI (OR 7.5, 95% CI 1.92-29.6, p = 0.004). Greater total vessel area, positive remodelling at the lesion site, and high volume of FFT in the coronary plaque are independently associated with increased risk of myocardial injury. Only positive RI was an independent predictor of PMI. Simple lesion morphology, rather than more complex VH-IVUS analysis or platelet reactivity, seems to predict myocardial injury after elective PCI.

Computed Tomographic Angiography–Verified Plaque Characteristics and Slow-Flow Phenomenon During Percutaneous Coronary Intervention

This study sought to identify whether computed tomographic angiographic (CTA) plaque characteristics are associated with slow-flow phenomenon (SF) during percutaneous coronary intervention (PCI). SF during PCI is associated with myocardial damage and prolonged hospitalization. Intracoronary ultrasound-verified large echolucent lesions have been reported to predict SF. The authors evaluated pre-PCI CTA plaque characteristics in 40 consecutive patients (male/female, 31/9; age, 69 ± 10 years) with stable angina pectoris who developed SF during PCI; patients with ≥ 600 Agatston coronary artery calcium score were not included. They were compared with 40 age-, sex-, and culprit coronary artery-matched patients (male/female, 31/9; age, 69 ± 9 years) who underwent PCI during the same period and did not develop SF. Plaque characteristics, including vascular remodeling, plaque consistency, including low-attenuation plaques representing lipid-rich lesions and high-attenuation plaque patterns of calcium deposition, were analyzed. Calcium deposition in the perimeter of a plaque, or circumferential plaque calcification (CPC), was significantly more frequent in the SF group (25 of 40, 63%) than the no-SF group (2 of 40, 5.0%) (p < 0.001). Presence of CPC on CTA was confirmed at the same location in the nonenhanced CT during Agatston coronary artery calcium score calculation. The positive remodeling index was significantly higher (1.5 [1.3 to 1.8] vs. 1.2 [1.0 to 1.5]; p < 0.001) and plaque density significantly lower (23.5 [9.5 to 40] HU vs. 45 [29 to 86] HU; p = 0.001) in the SF group. The conditional logistic regression analysis revealed that CPC, plaque density, and dyslipidemia were the predictors of SF, with CPC being the strongest (odds ratio: 79; 95% confidence interval: 8 to 783, p < 0.0001). CTA-verified CPC with low-attenuation plaque and positive remodeling were determinants of SF during PCI. If CTA findings are available in patients undergoing PCI, the interventionists should be aware of the likelihood of SF.

Microvascular Obstruction Is Caused by Atherothrombosis in Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention

The diagnosis of acute coronary syndrome (ACS) is primarily based on the mode of clinical presentation and is a term used for any conditions suggesting the acute induction of myocardial ischemia. The precise molecular and cellular triggers that lead to ACS remain poorly understood; however, histopathologic studies have illustrated several mechanisms that may explain the sudden onset of symptoms in ACS patients. The most common substrate underlying ACS is thought to be rupture of a vulnerable plaque that contains a necrotic core covered by a fibrous cap. The term, thin-cap fibroatheroma (TCFA) is used to describe vulnerable plaque because histomorphometric analysis of ruptured plaques revealed fibrous cap thickness to be 120 degree of circumferential arc; whereas thick cap fibroatheromas have the smallest necrotic core (1.2±2.2 mm2).2,3 The highest positive remodeling index is seen in plaque ruptures, followed by plaque hemorrhage, TCFA, healed plaque rupture, and fibroatheroma.4 Also, plaque rupture and TCFA are located predominantly in the proximal portions of the coronary tree.5 Following the rupture of plaque, the exposure of necrotic core material to blood flow leads to thrombotic luminal obstruction with or without distal embolization of platelet-rich thrombus, or less commonly, atherosclerotic debris. Article see p 620 The main causes of coronary thrombosis include plaque erosion as well as rupture, with erosion accounting for 25% to 35%, and rupture …

Arterial remodeling of advanced basilar atherosclerosis

There are limited studies on wall imaging of human basilar artery (BA). Our aim was to investigate remodeling mode of advanced BA atherosclerosis using 3-T MRI. Thirty-two consecutive symptomatic patients with atherosclerotic BA stenosis >or=70% were imaged with a 3-T magnetic resonance scanner. Proton density-weighted (PDW) cross-sectional images with submillimeter voxel size were obtained. The vessel area (VA) and lumen area (LA) at the maximal lumen narrowing (MLN) site and reference site were measured. Intraobserver and interobserver variability was determined by intraclass correlation coefficient (ICC). Wall area (WA) was estimated by VA - LA. Plaque size (PS) was estimated by WA at MLN site--reference WA. Percent plaque burden was calculated as (PS/VA at MLN site) x 100%. Remodeling index (RI) was the ratio of VA at MLN site to reference VA. RI >or=1.05 was defined as positive remodeling (PR) and RI <1.05 as non-PR. Measurements of cross-sectional BA images were available in 30 of 32 patients. Intraobserver or interobserver variability was small, with ICC ranging from 0.955 to 0.996. The mean RI of the 30 patients was 1.2 +/- 0.4. PR was found in 19 (63.3%) patients and non-PR in 11 (36.7%) patients. Compared with the non-PR group, the PR group had greater PS (15.0 +/- 9.3 mm(2) vs 6.4 +/- 3.9 mm(2), p = 0.007) and greater percent plaque burden (50.5 +/- 9.9% vs 28.5 +/- 12.7%, p < 0.0001). 3-T high-resolution PDW imaging is a reproducible tool for measuring BA dimensions. In patients with advanced BA atherosclerosis, PR lesions are more frequently observed and contain larger plaques than non-PR lesions.