Evidence of a chronic systemic cause of instability of atherosclerotic plaques

P2Y12 Receptor Inhibitor for Antiaggregant Therapies: From Molecular Pathway to Clinical Application

Platelets play a significant role in hemostasis, forming plugs at sites of vascular injury to limit blood loss. However, if platelet activation is not controlled, it can lead to thrombotic events, such as myocardial infarction and stroke. To prevent this, antiplatelet agents are used in clinical settings to limit platelet activation in patients at risk of arterial thrombotic events. However, their use can be associated with a significant risk of bleeding. An enhanced comprehension of platelet signaling mechanisms should facilitate the identification of safer targets for antiplatelet therapy. Over the past decade, our comprehension of the breadth and intricacy of signaling pathways that orchestrate platelet activation has expanded exponentially. Several recent studies have provided further insight into the regulation of platelet signaling events and identified novel targets against which to develop novel antiplatelet agents. Antiplatelet drugs are essential in managing atherothrombotic vascular disease. The current antiplatelet therapy in clinical practice is limited in terms of safety and efficacy. Novel compounds have been developed in response to patient variability and resistance to aspirin and/or clopidogrel. Recent studies based on randomized controlled trials and systematic reviews have definitively demonstrated the role of antiplatelet therapy in reducing the risk of cardiovascular events. Antiplatelet therapy is the recommended course of action for patients with established atherosclerosis. These studies compared monotherapy with a P2Y12 inhibitor versus aspirin for secondary prevention. However, in patients undergoing percutaneous coronary intervention, it is still unclear whether the efficacy of P2Y12 inhibitor monotherapy after a short course of dual antiplatelet therapy depends on the type of P2Y12 inhibitor. This paper focuses on the advanced-stage evaluation of several promising antiplatelet drugs.

A new predictor of coronary artery disease in acute ischemic stroke or transient ischemic attack patients: pericarotid fat density

OBJECTIVES

The study aims to evaluate the incremental predictive value of pericarotid fat density (PFD) on head and neck computed tomography angiography (CTA) for the obstructive coronary artery disease (CAD) (≥ 50% stenosis) relative to a clinical risk model (Framingham risk score (FRS)) and the degree of carotid artery stenosis and plaque type in acute ischemic stroke (AIS) or transient ischemic attack (TIA) patients without a known history of CAD.

METHODS

In a cohort of 134 consecutive stable patients diagnosed with AIS or TIA undergoing head and neck CTA between January 2010 and December 2021, pericarotid adipose tissue density (PFD) was quantified using a dedicated software. We collected demographic and clinical data, assessed the risk of CAD using the FRS, and analyzed coronary and carotid artery CTA images. Univariate and multivariate logistic regression analyses were performed to assess associations between FRS, PFD, CTA variables, and obstructive CAD risk. Four prediction models were established to evaluate the incremental predictive value of PFD relative to FRS, stenosis degree, and plaque types. Receiver operating characteristic (ROC) curves were generated, and the areas under the curves (AUC) were compared.

RESULTS

Increasing FRS, stenosis degree, and PFD values were positively correlated with obstructive CAD (all p < 0.05). In the predictive models for obstructive CAD, the model incorporating carotid stenosis exhibited superior predictive performance compared to FRS alone (p < 0.05). Moreover, the predictive model integrating PFD demonstrated enhanced performance and yielded the highest AUC of the receiver operator characteristic curve (AUC = 0.783), with sensitivity and specificity values of 86.89% and 65.75%, respectively.

CONCLUSION

CTA-derived PFD measurements offer supplementary predictive value for obstructive CAD beyond FRS and stenosis, thereby facilitating improved risk stratification of TIA or stroke patients without a history of CAD history.

CLINICAL RELEVANCE STATEMENT

CTA-derived PFD provides incremental predictive value for obstructive coronary artery disease in acute ischemic stroke or transient ischemic attack patients without CAD history, beyond Framingham risk score and carotid artery stenosis degree, improving risk stratification.

KEY POINTS

• Pericarotid fat density is associated with obstructive coronary artery disease in acute ischemic stroke or transient ischemic attack patients. • Higher pericarotid fat density corresponds to an increased risk of obstructive coronary artery disease. • Estimation of pericarotid fat density using computed tomography angiography imparts additional predictive value for obstructive CAD in risk stratification of acute ischemic stroke or transient ischemic attack patients.

Simultaneous 18-FDG PET and MR imaging in lower extremity arterial disease

Background

Simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) is a novel hybrid imaging method integrating the advances of morphological tissue characterization of MRI with the pathophysiological insights of PET applications.

Aim

This study evaluated the use of simultaneous 18-FDG PET/MR imaging for characterizing atherosclerotic lesions in lower extremity arterial disease (LEAD).

Methods

Eight patients with symptomatic stenoses of the superficial femoral artery (SFA) under simultaneous acquisition of 18-FDG PET and contrast-enhanced MRI using an integrated whole-body PET/MRI scanner. Invasive plaque characterization of the SFA was performed by intravascular imaging using optical coherence tomography. Histological analysis of plaque specimens was performed after directional atherectomy.

Results

MRI showed contrast enhancement at the site of arterial stenosis, as assessed on T2-w and T1-w images, compared to a control area of the contralateral SFA (0.38 ± 0.15 cm vs. 0.23 ± 0.11 cm; 1.77 ± 0.19 vs. 1.57 ± 0.15; p-value <0.05). On PET imaging, uptake of 18F-FDG (target-to-background ratio TBR > 1) at the level of symptomatic stenosis was observed in all but one patient. Contrast medium-induced MR signal enhancement was detected in all plaques, whereas FDG uptake in PET imaging was increased in lesions with active fibroatheroma and reduced in fibrocalcified lesions.

Conclusion

In this multimodal imaging study, we report the feasibility and challenges of simultaneous PET/MR imaging of LEAD, which might offer new perspectives for risk estimation.

Association between Carotid Intraplaque Neovascularization Detected by Contrast-Enhanced Ultrasound and the Progression of Coronary Lesions in Patients Undergoing Percutaneous Coronary Intervention

BACKGROUND

It is thought that the progression of vulnerable plaque is due in part to neovascularization, and plaque vulnerability is a useful approach for classifying cardiovascular risk. The aim of this retrospective study was to evaluate the correlation between carotid intraplaque neovascularization (IPN) detected on contrast-enhanced ultrasound and the progression of coronary lesions in patients undergoing percutaneous coronary intervention (PCI).

METHODS

Contrast-enhanced ultrasound and angiography were performed in 131 patients undergoing PCI. All patients had angiograms obtained ≥12 months after PCI, and progression was defined using those angiograms. On the basis of angiographic images, patients were divided into progression and nonprogression groups. IPN was graded from 0 to 3 according to each plaque's microbubble appearance and extent, detected using contrast-enhanced ultrasound. The plaque with the highest IPN was used for analysis. Logistic regression and receiver operating characteristic analyses were applied to evaluate risk factors for predicting the progression of coronary lesions in patients undergoing PCI.

RESULTS

In the progression group, the numbers of patients with IPN values of 0, 1, 2, and 3 were one (3.3%), nine (30.0%), 16 (53.3%), and four (13.3%), respectively. Significant differences were found in maximum plaque height and IPN between groups. IPN and maximum plaque height were independent risk contributors to coronary lesion progression in patients undergoing PCI. The sensitivity, specificity, positive predictive value, and negative predictive value of IPN of 1.5 and to predict the progression of coronary lesions were 67%, 91%, 68%, and 89%, respectively. The area under the curve was 0.822.

CONCLUSIONS

Carotid plaque neovascularization was correlated with the progression of coronary lesions in patients undergoing PCI. IPN is a clinically useful tool for detecting the progression of coronary lesions and for risk stratification, especially in patients >60 years old.

Identification of Symptomatic Carotid Artery Plaque: A Three-Item Scale Combined Angiography With Optical Coherence Tomography

Introduction: Symptomatic carotid disease conveys a high risk of recurrent stroke. Plaque morphology and specific plaque characteristics are associated with the risk of stroke. This study aimed to evaluate the detailed plaque features by optical coherence tomography (OCT) and develop a simple scale combining clinical indicators, digital subtraction angiography (DSA), and OCT imaging markers to identify symptomatic carotid plaque. Methods: Carotid plaques from consecutive patients who underwent carotid OCT imaging between June 2017 and June 2021 were evaluated. Clinical characteristics, DSA, and OCT data were compared between the symptomatic and asymptomatic groups. Logistic regression was performed to identify the factors associated with symptomatic carotid plaque and to develop a scale. The area under the receiver operating characteristic curve (AUC) was used to evaluate the performance of the scale. Results: A total of 90 carotid plaques from 90 patients were included (symptomatic 35.6%, asymptomatic 64.4%). Three main factors were found to be associated with symptomatic carotid plaque: high-density lipoprotein cholesterol (HDL-C) <0.925 mmol/L (OR, 4.708; 95% CI, 1.640 to 13.517; P = 0.004), irregular plaque (OR, 4.017; 95% CI, 1.250 to 12.910; P = 0.020), and white thrombus (OR, 4.594; 95% CI, 1.141 to 18.487; P = 0.032). The corresponding score of three items produced a scale with good discrimination (AUC, 0.768; 95% CI, 0.665 to 0.871). The optimal cutoff value of the scale was 1.5 points with 59.4% sensitivity and 84.5% specificity. Conclusion: The three-item scale comprising HDL-C <0.925 mmol/L, angiographical irregular plaque, and white thrombus detected by OCT may provide information to identify symptomatic carotid plaque. Further large-scale studies are required to validate whether the symptomatic carotid plaque scale is clinically valuable in recognizing carotid atherosclerosis in the early stages.

Improvement in Brachial Endothelial Vasomotor Function and Brachial-Ankle Pulse Wave Velocity Reduces the Residual Risk for Cardiovascular Events after Optimal Medical Treatment in Patients with Coronary Artery Disease

Aim: To examine whether improvement in flow-mediated endothelium-dependent dilatation (FMD) of the brachial artery and brachial-ankle pulse wave velocity (baPWV) has an additive effect on achieving optimal goals of traditional risk factors to reduce cardiovascular risk in patients with coronary artery disease (CAD).

Methods: We assessed 323 patients with CAD and impaired vascular function, defined as an impaired FMD of the brachial artery (＜5.5%) and increased baPWV (＞1,440 cm/sec). After FMD and baPWV measurements at 24 weeks of optimal medical treatment (OMT), the study patients were followed up for ＜60 months or until a composite of cardiac death, nonfatal myocardial infarction (MI), unstable angina, or ischemic stroke occurs.

Results: During the median follow-up period of 35 months, cardiovascular events occurred in 72 patients. Multivariate Cox hazards analysis showed that patients with an improvement in FMD and baPWV had the lowest probability of future cardiovascular events. In addition, the improvement in FMD and baPWV had a significant incremental effect on the predictive value of the achievement of optimal goals for blood pressure (BP), low-density lipoprotein cholesterol (LDL-C), and hemoglobin A1c (HbA1c) using net reclassification improvement (NRI) and integrated discrimination improvement (IDI).

Conclusions: The improvement in FMD and baPWV had additive effects on risk reduction of the achievement of the optimal goals of traditional risk factors in patients with CAD. Thus, serial measurements of FMD and baPWV may be useful for identifying CAD patients at residual risk for adverse cardiovascular events following OMT.

The association of lipoprotein(a) and intraplaque neovascularization in patients with carotid stenosis: a retrospective study

Background

Lipoprotein(a) is genetically determined and increasingly recognized as a major risk factor for arteriosclerotic cardiovascular disease. We examined whether plasma lipoprotein(a) concentrations were associated with intraplaque neovascularization (IPN) grade in patients with carotid stenosis and in terms of increasing plaque susceptibility to haemorrhage and rupture.

Methods

We included 85 patients diagnosed with carotid stenosis as confirmed using carotid ultrasound who were treated at Guangdong General Hospital. Baseline data, including demographics, comorbid conditions and carotid ultrasonography, were recorded. The IPN grade was determined using contrast-enhanced ultrasound through the movement of the microbubbles. Univariate and multivariate binary logistic regression analyses were used to evaluate the association between lipoprotein(a) and IPN grade, with stepwise adjustment for covariates including age, sex, comorbid conditions and statin therapy (model 1), total cholesterol, triglyceride, low-density lipoprotein cholesterol calculated by Friedwald's formula, high-density lipoprotein cholesterol, apolipoprotein A and apolipoprotein B (model 2), maximum plaque thickness and total carotid maximum plaque thickness, degree of carotid stenosis and internal carotid artery (ICA) occlusion (model 3).

Results

Lipoprotein(a) was a significant predictor of higher IPN grade in binary logistic regression before adjusting for other risk factors (odds ratio [OR] 1.238, 95% confidence interval [CI] (1.020, 1.503), P = 0.031). After adjusting for other risk factors, lipoprotein(a) still remained statistically significant in predicting IPN grade in all model. (Model 1: OR 1.333, 95% CI 1.074, 1.655, P = 0.009; Model 2: OR 1.321, 95% CI 1.059, 1.648, P = 0.014; Model 3: OR 1.305, 95% CI 1.045, 1.628, P = 0.019). Lp(a) ≥ 300 mg/L is also significantly related to IPN compare to < 300 mg/L (OR 2.828, 95% CI 1.055, 7.580, P = 0.039) as well as in model 1, while in model 2 and model 3 there are not significant difference.

Conclusions

Plasma lipoprotein(a) concentrations were found to be independently associated with higher IPN grade in patients with carotid stenosis. Lowering plasma lipoprotein(a) levels may result in plaque stabilization by avoiding IPN formation.

Carotid Artery Atherosclerotic Profile as Risk Predictor for Restenosis After Coronary Stenting

BACKGROUND

The incidence of restenosis of the coronary artery after a bare-metal stent implant has been lower than in simple balloon angioplasty; however, it still shows relatively high rates.

OBJECTIVE

The aim of this study was to find new risk indicators for in-stent restenosis using carotid ultrasonography, that, in addition to the already existing indicators, would help in decision-making for stent selection.

METHODS

We carried out a cross-sectional prospective study including 121 consecutive patients with chronic coronary artery disease who had undergone percutaneous coronary intervention with repeat angiography in the previous 12 months. After all cases of in-stent restenosis were identified, patients underwent carotid ultrasonography to evaluate carotid intima-media thickness and atherosclerosis plaques. The data were analyzed by Cox multiple regression. The significance level was set a p<0.05.

RESULTS

Median age of patients was 60 years (1st quartile = 55, 3rd quartile = 68), and 64.5% of patients were male. Coronary angiography showed that 57 patients (47.1%) presented in-stent restenosis. Fifty-five patients (45.5%) had echolucent atherosclerotic plaques in carotid arteries and 54.5% had echogenic plaques or no plaques. Of patients with who had echolucent plaques, 90.9% presented coronary in-stent restenosis. Of those who had echogenic plaques or no plaques, 10.6% presented in-stent restenosis. The presence of echolucent plaques in carotid arteries increased the risk of coronary in-stent restenosis by 8.21 times (RR=8.21; 95%CI: 3.58-18.82; p<0.001).

CONCLUSIONS

The presence of echolucent atherosclerotic plaques in carotid artery constitutes a risk predictor of coronary instent restenosis and should be considered in the selection of the type of stent to be used in coronary angioplasty.

Association of Polyvascular Disease and Elevated Interleukin-6 With Outcomes in Acute Ischemic Stroke or Transient Ischemic Attack

Background: Polyvascular disease (PolyVD) and interleukin (IL)-6 are associated with poor outcomes in patients with stroke respectively. However, whether combined PolyVD and elevated IL-6 levels would increase the risk of poor outcomes of stroke patients is yet unclear.

Methods: Data were obtained from the Third China National Stroke Registry (CNSR-III). PolyVD was defined as acute ischemic stroke (AIS) or transient ischemic attack (TIA) with coronary artery disease (CAD) and/or peripheral artery disease (PAD). Patients were divided into four groups according to the combination of vascular beds number (non-PolyVD or PolyVD) and IL-6 levels (IL-6 < 2.64 pg/mL or IL-6 ≥ 2.64 pg/mL). The primary outcome was a recurrent stroke at 1-year follow-up. Cox proportional hazard models were employed to identify the association of the combined effect of PolyVD and IL-6 with the prognosis of patients.

Results: A total of 10,773 patients with IL-6 levels and 1-year follow-up were included. The cumulative incidence of recurrent stroke was 9.87% during the 1-year follow-up. Compared to non-PolyVD and IL-6<2.64 pg/mL patients, patients had non-PolyVD with IL-6 ≥ 2.64 pg/mL (HR 1.245 95%CI 1.072–1.446; P < 0.001) and PolyVD with IL-6 <2.64 pg/mL (HR 1.251 95%CI 1.002–1.563; P = 0.04) were associated with an increased risk of recurrent stroke during 1-year follow-up. Likewise, patients with PolyVD and IL-6 ≥ 2.64 pg/mL (HR 1.290; 95% CI 1.058–1.572; P = 0.01) had the highest risk of recurrent stroke at 1-year follow-up among groups.

Conclusion: PolyVD and elevated IL-6 levels are both associated with poor outcomes in patients with AIS or TIA. Moreover, the combination of them increases the efficiency of stroke risk stratification compared with when used alone. More attention and intensive treatment should be given to those patients with both PolyVD and elevated IL-6 levels.

Impact of Prior Stroke on Long-Term Outcomes in Patients With Acute Coronary Syndrome

Background: Cerebrovascular disease often coexists with coronary artery disease (CAD), and it has been associated with worse clinical outcomes in CAD patients. However, the prognostic effect of prior stroke on long-term outcomes in patients with acute coronary syndrome (ACS) is still unclear.

Methods and Results: An observational cohort study of ACS patients who underwent emergency percutaneous coronary intervention (PCI) between January 1999 and May 2015 was conducted. Patients were divided into 2 groups according to their history of stroke. We evaluated both all-cause death and cardiac death. Of the 2,548 consecutive ACS patients in the current cohort, 268 (10.5%) had a history of stroke at the onset of ACS. Patients with a history of stroke were older and had a higher prevalence of comorbidities such as hypertension or renal deficiency. The cumulative incidences of all-cause death and cardiac death were significantly higher in patients with a history of stroke (both log-rank P<0.0001). Multivariate Cox hazard regression analysis showed that a history of stroke was significantly associated with the incidences of all-cause death (hazard ratio [HR] 1.49, 95% confidence interval [CI] 1.20–1.85, P=0.0004) and cardiac death (HR 1.41, 95% CI 1.03–1.93, P=0.03).

Conclusions: About 10% of the ACS patients had a history of stroke and had worse clinical outcomes.

Echolucency of carotid plaque is useful for selecting high-risk patients with chronic coronary artery disease who benefit from intensive lipid-lowering therapy

BACKGROUND

Ultrasound assessment of the carotid artery provides prognostic information on coronary events. This study examined whether ultrasound assessments of plaque echolucency of the carotid artery are useful for identifying patients with coronary artery disease (CAD) who are at high risk but could benefit from lipid-lowering therapy for secondary prevention.

METHODS

Ultrasound assessment of carotid plaque echolucency with integrated backscatter (IBS) analysis was performed in 393 chronic CAD patients with low-density lipoprotein cholesterol (LDL-C) levels <100 mg/dL on statin therapy. All patients were prospectively followed up for a maximum of 96 months or until the occurrence of one of the following coronary events: cardiac death, nonfatal myocardial infarction, or unstable angina pectoris requiring unplanned revascularization.

RESULTS

During the follow-up period, 45 coronary events occurred. Patients were stratified by IBS (≤-16.3 or >-16.3 dB, median value) and LDL-C level (<70 or 70-99 mg/dL). Multivariate Cox proportional hazards analysis showed that patients with lower IBS and LDL-C 70-99 mg/dL had significantly higher probabilities of coronary events compared with those with higher IBS and LDL-C <70 mg/dL, after adjustment for a baseline model of risk factors (hazard ratio 5.15; 95% confidence interval 1.21-22.0, p = 0.03). In contrast, patients with lower IBS and LDL-C <70 mg/dL had an improved prognosis comparable with those with higher IBS. Addition of LDL-C levels to the baseline model of risk factors improved net reclassification improvement (NRI) and integrated discrimination improvement (IDI) in patients with lower IBS (NRI, 0.44, p = 0.04; and IDI, 0.035, p < 0.01), but not in those with higher IBS.

CONCLUSIONS

Evaluation of echolucency of the carotid artery was useful for selecting CAD patients at high risk of secondary coronary events but who could benefit from lipid-lowering therapy.

CT texture-based radiomics analysis of carotid arteries identifies vulnerable patients: a preliminary outcome study

PURPOSE

To assess the potential role of computed tomography (CT) texture analysis (CTTA) in identifying vulnerable patients with carotid artery atherosclerosis.

METHODS

In this case-control pilot study, 12 patients with carotid atherosclerosis and a subsequent history of transient ischemic attack or stroke were age and sex matched with 12 control cases with asymptomatic carotid atherosclerosis (follow-up time 103.58 ± 9.2 months). CTTA was performed using a commercially available research software package (TexRAD) by an operator blinded to clinical data. CTTA comprised a filtration-histogram technique to extract features at different scales corresponding to spatial scale filter (fine = 2 mm, medium = 3 mm, coarse = 4 mm), followed by quantification using histogram-based statistical parameters: mean, kurtosis, skewness, entropy, standard deviation, and mean value of positive pixels. A single axial slice was selected to best represent the largest cross-section of the carotid bifurcation or the greatest degree of stenosis, in presence of an atherosclerotic plaque, on each side.

RESULTS

CTTA revealed a statistically significant difference in skewness between symptomatic and asymptomatic patients at the medium (0.22 ± 0.35 vs - 0.18 ± 0.39, p < 0.001) and coarse (0.23 ± 0.22 vs 0.03 ± 0.29, p = 0.003) texture scales. At the fine-texture scale, skewness (0.20 ± 0.59 vs - 0.18 ± 0.58, p = 0.009) and standard deviation (366.11 ± 117.19 vs 300.37 ± 82.51, p = 0.03) were significant before correction.

CONCLUSION

Our pilot study highlights the potential of CTTA to identify vulnerable patients in stroke and TIA. CT texture may have the potential to act as a novel risk stratification tool in patients with carotid atherosclerosis.

Cerebral autoregulation is heterogeneous in different stroke mechanism of ischemic stroke caused by intracranial atherosclerotic stenosis

BACKGROUND AND PURPOSE

Intracranial atherosclerotic stenosis (ICAS) is the most common cause of ischemic stroke (IS) and is associated with stroke recurrence. It results in IS due to a variety of mechanisms. However, the influence of brain reserve mechanism on different stroke mechanism is still unclear. Cerebral autoregulation (CA) is an important brain reserve mechanism and is impaired after IS. This study aimed to explore the impaired pattern of CA and assess the association between CA and stroke risk factors in different stroke mechanism caused by ICAS.

METHODS

IS patients with ICAS (50%-99% stenosis/occlusion) in middle cerebral artery (MCA) or internal carotid artery were enrolled to receive CA examinations within 7 days after onset. Healthy volunteers were also recruited as controls. CA was recorded from spontaneous fluctuations of blood pressure and MCA flow velocity. Transfer function analysis was used to derive CA parameters, including phase difference (PD) and coherence in the low-frequency range (0.06-0.12 Hz).

RESULTS

A total of 89 IS patients and 90 healthy controls were included. Compared with controls, CA was impaired ipsilaterally in patients with parent artery atherosclerosis occluding penetrating artery (POPA) while CA was bilaterally impaired in other stroke mechanisms. And CA on ipsilateral hemisphere was correlated with hypertension/hyperlipidemia in patients with POPA (r = -0.481, p = .008; r = -0.484, p = .008). While CA on ipsilateral hemisphere was correlated with perfusion parameter including the arterial spin-labeling (ASL) parameter cerebral blood flow (CBF) (r = 0.893, p = .007) and collateral circulation status the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) (r = 0.610, p = .021) in patients with hypoperfusion mechanism.

CONCLUSION

In IS patients, CA was impaired heterogeneously and was correlated with different risk factors in varied stroke mechanism. CA can be as an informative determinant of stroke risk in patients with ICAS and to help improving individualized treatment strategies in the presence of ischemic stroke caused by ICAS.

Carotid intraplaque neovascularization predicts coronary artery disease and cardiovascular events

AIMS

It is thought that the majority of cardiovascular (CV) events are caused by vulnerable plaque. Such lesions are rupture prone, in part due to neovascularization. It is postulated that plaque vulnerability may be a systemic process and that vulnerable lesions may co-exist at multiple sites in the vascular bed. This study sought to examine whether carotid plaque vulnerability, characterized by contrast-enhanced ultrasound (CEUS)-assessed intraplaque neovascularization (IPN), was associated with significant coronary artery disease (CAD) and future CV events.

METHODS AND RESULTS

We investigated carotid IPN using carotid CEUS in 459 consecutive stable patients referred for coronary angiography. IPN was graded based on the presence and location of microbubbles within each plaque (0, not visible; 1, peri-adventitial; and 2, plaque core). The grades of each plaque were averaged to obtain an overall score per patient. Coronary plaque severity and complexity was also determined angiographically. Patients were followed for 30 days following their angiogram. This study found that a higher CEUS-assessed carotid IPN score was associated with significant CAD (≥50% stenosis) (1.8 ± 0.4 vs. 0.5 ± 0.6, P < 0.0001) and greater complexity of coronary lesions (1.7 ± 0.5 vs. 1.3 ± 0.8, P < 0.0001). Furthermore, an IPN score ≥1.25 could predict significant CAD with a high sensitivity (92%) and specificity (89%). The Kaplan-Meier analysis demonstrated a significantly higher proportion of participants having CV events with an IPN score ≥1.25 (P = 0.004).

CONCLUSION

Carotid plaque neovascularization was found to be predictive of significant and complex CAD and future CV events. CEUS-assessed carotid IPN is a clinically useful tool for CV risk stratification in high-risk cardiac patients.

The management of carotid restenosis: a comprehensive review

Carotid artery stenosis (CS) is a major medical problem affecting approximately 10% of the general population 80 years or older and causes stroke in approximately 10% of all ischemic events. In patients with symptomatic, moderate-to-severe CS, carotid endarterectomy (CEA) and carotid angioplasty and stenting (CAS), has been used to lower the risk of stroke. In primary CS, CEA was found to be superior to best medical therapy (BMT) according to 3 large randomized controlled trials (RCT). Following CEA and CAS, restenosis remains an unsolved problem involving a large number of patients as the current treatment recommendations are not as clear as those for primary stenosis. Several studies have evaluated the risk of restenosis, reporting an incidence ranging from 5% to 22% after CEA and an in-stent restenosis (ISR) rate ranging from 2.7% to 33%. Treatment and optimal management of this disease process, however, is a matter of ongoing debate, and, given the dearth of level 1evidence for the management of these conditions, the relevant guidelines lack clarity. Moreover, the incidence rates of stroke and complications in patients with carotid stenosis are derived from studies that did not use contemporary techniques and materials. Rapidly changing guidelines, updated techniques, and materials, and modern medical treatments make actual incidence rates barely comparable to previous ones. For these reasons, RCTs are critical for determining whether these patients should be treated with more aggressive treatments additional to BMT and identifying those patients indicated for surgical or endovascular treatments. This review summarizes the current evidence and controversies concerning the risks, causes, current treatment options, and prognoses in patients with restenosis after CEA or CAS.

Carotid intraplaque neovascularization predicts atherosclerotic renal artery stenosis in patients with carotid artery stenosis

BACKGROUND AND AIMS

This study aimed to examine whether intraplaque neovascularization (IPN) of carotid plaques, as characterized by contrast-enhanced ultrasound (CEUS), is associated with atherosclerotic renal artery stenosis (ARAS) in patients with normal kidney function.

METHODS AND RESULTS

We investigated carotid IPN using CEUS in 198 consecutive patients with normal kidney function with and without ARAS. IPN was graded on the basis of the presence and location of microbubbles within each plaque (0, no visible microbubbles in the plaque; 1, moderate microbubbles confined to the shoulder and/or adventitial side of the plaque; and 2, extensive microbubbles throughout the plaque). The grades of each plaque were averaged to obtain an overall score per patient. ARAS was determined angiographically. We found that a higher CEUS-assessed carotid IPN score was associated with ARAS (Odd Ratio, OR: 7.281; 95% Confidence Interval, 95% CI: 3.246-16.336; P < 0.001). Furthermore, an IPN score >1.75 predicted severe stenosis with a sensitivity of 81% and specificity of 58%. Compared with using the IPN score alone, the addition of the homocysteine (HCY) cutoff value (>22.5 mmol/L) resulted in a stronger predictive value (Area Under Curve, AUC: 0.893 vs 0.834; P < 0.001) for severe ARAS.

CONCLUSION

Carotid plaque neovascularization combined with HCY levels is predictive of severe ARAS in patients with normal kidney function. CEUS-assessed carotid IPN is clinically useful for stratification of ARAS in patients with normal kidney function.

Sustained Focal Vascular Inflammation Accelerates Atherosclerosis in Remote Arteries

OBJECTIVE

Evidence from preclinical and clinical studies has demonstrated that myocardial infarction promotes atherosclerosis progression. The impact of focal vascular inflammation on the progression and phenotype of remote atherosclerosis remains unknown. Approach and Results: We used a novel ApoE^-/- knockout mouse model of sustained arterial inflammation, initiated by mechanical injury in the abdominal aorta. Using serial in vivo molecular MRI and ex vivo histology and flow cytometry, we demonstrate that focal arterial inflammation triggered by aortic injury, accelerates atherosclerosis in the remote brachiocephalic artery. The brachiocephalic artery atheroma had distinct histological features including increased plaque size, plaque permeability, necrotic core to collagen ratio, infiltration of more inflammatory monocyte subsets, and reduced collagen content. We also found that arterial inflammation following focal vascular injury evoked a prolonged systemic inflammatory response manifested as a persistent increase in serum IL-6 (interleukin 6). Finally, we demonstrate that 2 therapeutic interventions-pravastatin and minocycline-had distinct anti-inflammatory effects at the plaque and systemic level.

CONCLUSIONS

We show for the first time that focal arterial inflammation in response to vascular injury enhances systemic vascular inflammation, accelerates remote atheroma progression and induces plaques more inflamed, lipid-rich, and collagen-poor in the absence of ischemic myocardial injury. This inflammatory cascade is modulated by pravastatin and minocycline treatments, which have anti-inflammatory effects at both plaque and systemic levels that mitigate atheroma progression.

Impact of peripheral artery disease on prognosis after myocardial infarction: The J-MINUET study

BACKGROUND

Patients with peripheral artery disease (PAD) are at high risk of cardiovascular events, including myocardial infarction (MI), stroke, and cardiovascular death. However, the impact of PAD on prognosis in Japanese patients with acute MI remains unclear.

METHODS

The Japanese registry of acute Myocardial INfarction diagnosed by Universal dEfiniTion (J-MINUET) is a prospective multicenter registry that registered 3283 patients with acute MI. Among them, 2970 patients with available data of PAD were divided into the following 4 groups: 2513 patients without prior MI or PAD (None group), 320 patients with only prior MI (Prior MI group), 100 patients with only PAD (PAD group), and 37 patients with both previous MI and PAD (Both group). The primary endpoint was a composite of all-cause death, non-fatal MI, non-fatal stroke, cardiac failure, and urgent revascularization for unstable angina.

RESULTS

The 3-year cumulative incidence of the primary endpoint was 26.9% in None group, 41.4% in Prior MI group, 48.0% in PAD group, and 60.3% in Both group (p < 0.001). In multivariate analysis, hazard ratio using None group as reference was 1.55 (95% confidence intervals 1.25-1.91; p < 0.001) for MI group, 2.26 (1.61-3.07; p < 0.001) for PAD group, and 2.52 (1.52-3.90; p < 0.001) for Both group.

CONCLUSIONS

Concomitant PAD was associated with poor prognosis in Japanese patients with acute MI.

Monotherapy with a P2Y12 inhibitor or aspirin for secondary prevention in patients with established atherosclerosis: a systematic review and meta-analysis

BACKGROUND

Antiplatelet therapy is recommended among patients with established atherosclerosis. We compared monotherapy with a P2Y₁₂ inhibitor versus aspirin for secondary prevention.

METHODS

In this systematic review and meta-analysis, all randomised trials comparing P2Y₁₂ inhibitor with aspirin monotherapy for secondary prevention in patients with cerebrovascular, coronary, or peripheral artery disease were evaluated for inclusion. On Dec 18, 2019, we searched PubMed, Embase, BioMedCentral, Google Scholar, and the Cochrane Central Register of Controlled Trials. Additionally, we reviewed references from identified articles and searched abstracts from 2017 to 2019 presented at relevant scientific meetings. Data about year of publication, inclusion and exclusion criteria, sample size, baseline patients' features including the baseline condition determining study inclusion (ie, cerebrovascular, coronary, or peripheral artery disease), P2Y₁₂ inhibitor type and dosage, aspirin dosage, endpoint definitions, effect estimates, follow-up duration, and percentage of patients lost to follow-up were collected. Odds ratios (ORs) and 95% CIs were used as metric of choice for treatment effects with random-effects models. Co-primary endpoints were myocardial infarction and stroke. Key secondary endpoints were all-cause death and vascular death. Heterogeneity was assessed with the I² index. This study is registered with PROSPERO (CRD42018115037).

FINDINGS

A total of nine randomised trials were identified and included in this study, and 42 108 patients randomly allocated to a P2Y₁₂ inhibitor (n=21 043) or aspirin (n=21 065) were included in our analyses. Patients who received a P2Y₁₂ inhibitor had a borderline reduction for the risk of myocardial infarction compared with those who received aspirin (OR 0·81 [95% CI 0·66-0·99]; I²=10·9%). Risks of stroke (OR 0·93 [0·82-1·06]; I²=34·5%), all-cause death (OR 0·98 [0·89-1·08]; I²=0%), and vascular death (OR 0·97 [0·86-1·09]; I²=0%) did not differ between patients who received a P2Y₁₂ inhibitor and those who received aspirin. Similarly, the risk of major bleeding (OR 0·90 [0·74-1·10]; I²=3·9%) did not differ between patients who received a P2Y₁₂ inhibitor and those who received aspirin. The number needed to treat to prevent one myocardial infarction with P2Y₁₂ inhibitor monotherapy was 244 patients. Findings were consistent regardless of the type of P2Y₁₂ inhibitor used.

INTERPRETATION

Compared with aspirin monotherapy, P2Y₁₂ inhibitor monotherapy is associated with a risk reduction for myocardial infarction and a comparable risk of stroke in the setting of secondary prevention. The benefit of P2Y₁₂ inhibitor monotherapy is of debatable clinical relevance, in view of the high number needed to treat to prevent a myocardial infarction and the absence of any effect on all-cause and vascular mortality.

FUNDING

Italian Ministry of Education.

Associations between systemic blood pressure parameters and intraplaque hemorrhage in symptomatic intracranial atherosclerosis: a high-resolution MRI-based study

The associations between blood pressure parameters and intracranial vulnerable plaques have not been fully elucidated. The purpose of this study was to investigate the associations between systemic blood pressure parameters, as well as their variability, and intraplaque hemorrhage (IPH) in stroke patients with intracranial atherosclerosis. We retrospectively analyzed the high-resolution MRI data set of intracranial atherosclerosis from a comprehensive stroke center. The atherosclerotic plaque burden and presence of IPH in each vessel were obtained from vessel wall imaging. Blood pressure parameters in the first week of admission were used. The systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), and their variability (standard deviation [SD] and coefficient of variation [CV]) were compared between the IPH (+) and IPH (-) groups. Logistic regression analysis was used to demonstrate the correlations between different blood pressure parameters and IPH. The results indicated that SBP and PP were associated with multiple plaques and severe luminal stenosis after adjusting for confounders, with OR = 1.071, 95% CI: (1.044-1.098) and OR = 1.039, 95% CI: (1.019-1.060) for SBP and OR = 1.058, 95% CI: (1.027-1.089) and OR = 1.044, 95% CI: (1.019-1.070) for PP, respectively. SBP was associated with IPH after adjusting for cardiovascular risk factors, with OR = 1.021, 95% CI: (1.003-1.038), but not after correcting for plaque burden, with OR = 1.014, 95% CI: (0.996-1.032). No associations between blood pressure variability and atherosclerotic plaque burden or IPH were detected in this study. In conclusion, SBP is associated with IPH after adjusting for cardiovascular risk factors but not after further correction for atherosclerotic plaque burden. The association between blood pressure variability and intracranial atherosclerosis requires further study.

Coronary Atherosclerosis Imaging

Identifying patients at increased risk of coronary artery disease, before the atherosclerotic complications become clinically evident, is the aim of cardiovascular prevention. Imaging techniques provide direct assessment of coronary atherosclerotic burden and pathological characteristics of atherosclerotic lesions which may predict the progression of disease. Atherosclerosis imaging has been traditionally based on the evaluation of coronary luminal narrowing and stenosis. However, the degree of arterial obstruction is a poor predictor of subsequent acute events. More recent techniques focus on the high-resolution visualization of the arterial wall and the coronary plaques. Most acute coronary events are triggered by plaque rupture or erosion. Hence, atherosclerotic plaque imaging has generally focused on the detection of vulnerable plaque prone to rupture. However, atherosclerosis is a dynamic process and the plaque morphology and composition may change over time. Most vulnerable plaques undergo progressive transformation from high-risk to more stable and heavily calcified lesions, while others undergo subclinical rupture and healing. Although extensive plaque calcification is often associated with stable atherosclerosis, the extent of coronary artery calcification strongly correlates with the degree of atherosclerosis and with the rate of future cardiac events. Inflammation has a central role in atherogenesis, from plaque formation to rupture, hence in the development of acute coronary events. Morphologic plaque assessment, both invasive and non-invasive, gives limited information as to the current activity of the atherosclerotic disease. The addition of nuclear imaging, based on radioactive tracers targeted to the inflammatory components of the plaques, provides a highly sensitive assessment of coronary disease activity, thus distinguishing those patients who have stable disease from those with active plaque inflammation.

Exosome-Transmitted miR-25 Induced by H. pylori Promotes Vascular Endothelial Cell Injury by Targeting KLF2

Background: Increasing evidence has shown that Helicobacter pylori is associated with coronary heart disease (CHD); however, the underlying mechanism remains unclear. Methods: The expression of miR-25 and mRNAs was measured using qRT-PCR. Protein levels were detected using western blotting and exosomes were assessed with an electron microscope. The target gene of miR-25 was identified using the luciferase report system. Results: H. pylori infection increased the expression of miR-25 in gastric epithelial cells and was associated with increased levels of exosome-transmitted miR-25 in human peripheral blood. Mechanistic investigation showed the Kruppel-like factor 2 (KLF2) was a direct target of exosome-transmitted miR-25 in vascular endothelial cells. In addition, the miR-25/KLF2 axis regulated the NF-κB signaling pathway, resulting in increased expression of interleukin 6 (IL6), monocyte chemoattractant protein-1 (MCP-1), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1). Conclusion: Our findings suggest that the miR-25/KLF2 axis may be a potential therapeutic target for H. pylori-associated CHD. Furthermore, high levels of exosome-transmitted miR-25 in peripheral blood may pose a potential risk for CHD.

Coronary Artery Microcalcification: Imaging and Clinical Implications

Strategies to prevent acute coronary and cerebrovascular events are based on accurate identification of patients at increased cardiovascular (CV) risk who may benefit from intensive preventive measures. The majority of acute CV events are precipitated by the rupture of the thin cap overlying the necrotic core of an atherosclerotic plaque. Hence, identification of vulnerable coronary lesions is essential for CV prevention. Atherosclerosis is a highly dynamic process involving cell migration, apoptosis, inflammation, osteogenesis, and intimal calcification, progressing from early lesions to advanced plaques. Coronary artery calcification (CAC) is a marker of coronary atherosclerosis, correlates with clinically significant coronary artery disease (CAD), predicts future CV events and improves the risk prediction of conventional risk factors. The relative importance of coronary calcification, whether it has a protective effect as a stabilizing force of high-risk atherosclerotic plaque has been debated until recently. The extent of calcium in coronary arteries has different clinical implications. Extensive plaque calcification is often a feature of advanced and stable atherosclerosis, which only rarely results in rupture. These macroscopic vascular calcifications can be detected by computed tomography (CT). The resulting CAC scoring, although a good marker of overall coronary plaque burden, is not useful to identify vulnerable lesions prone to rupture. Unlike macrocalcifications, spotty microcalcifications assessed by intravascular ultrasound or optical coherence tomography strongly correlate with plaque instability. However, they are below the resolution of CT due to limited spatial resolution. Microcalcifications develop in the earliest stages of coronary intimal calcification and directly contribute to plaque rupture producing local mechanical stress on the plaque surface. They result from a healing response to intense local macrophage inflammatory activity. Most of them show a progressive calcification transforming the early stage high-risk microcalcification into the stable end-stage macroscopic calcification. In recent years, new developments in noninvasive cardiovascular imaging technology have shifted the study of vulnerable plaques from morphology to the assessment of disease activity of the atherosclerotic lesions. Increased disease activity, detected by positron emission tomography (PET) and magnetic resonance (MR), has been shown to be associated with more microcalcification, larger necrotic core and greater rates of events. In this context, the paradox of increased coronary artery calcification observed in statin trials, despite reduced CV events, can be explained by the reduction of coronary inflammation induced by statin which results in more stable macrocalcification.

New Quantitative Digital Image Analysis Method of Histological Features of Carotid Atherosclerotic Plaques

OBJECTIVE

Atherosclerosis and its thrombotic complications are major causes of morbidity and mortality worldwide. Plaque stability assessment is considered to be important for both clinical and fundamental applications. The current gold standard method to investigate plaque stability is performed by histological assessment of plaque features using semi-quantitative classifications. However, these assessments can be limited by subjectivity and variability. Thus, the aim was to develop a new digital image analysis method to measure quantitatively individual plaque features that is more precise than existing semi-quantitative methods.

METHODS

A quantitative method was developed using Image Pro Primer software. Carotid plaque specimens were obtained from patients who underwent carotid endarterectomy and categorised according to stability (definitely stable, probably stable, probably unstable, definitely unstable) based on the gold standard semi-quantitative method that assesses 10 histological plaque features. Using the new quantitative method, plaque features (n = 15) from each stability grade were then analysed by two independent raters. For the semi-quantitative analysis, quadratic weighted Cohen's kappa was used to test intra- and inter-rater reliability, while for the quantitative analysis, intraclass correlation coefficients (ICCs) were assessed.

RESULTS

Intra-rater reliability demonstrated almost perfect agreement between both methods (Cohen's kappa range 0.831-0.969, ICC range 0.848-1.000). However, inter-rater reliability demonstrated mainly fair to moderate agreement (Cohen's kappa range 0.341-0.778) for the semi-quantitative analysis, while the digital image analysis method performed most optimally regarding reproducibility, yielding high ICCs close to 1 (ICC range 0.816-0.999). Using quantitative measurements, a statistically significant proportion of the individual plaque features (p < .05) were re-classified from one grade to another (shift by one) under the semi-quantitative classification.

CONCLUSION

A new quantitative digital image analysis was developed for the accurate assessment of histological plaque features, which demonstrated higher precision than the gold standard semi-quantitative methods, as measured by between and within rater analysis. Moreover, quantitative image analysis of histological plaque features provided more detailed insight into plaque morphology and composition.

Blood pressure at age 40 predicts carotid atherosclerosis two decades later: data from the Akershus Cardiac Examination 1950 Study

OBJECTIVE

We assessed the impact of a single time-point measurement of SBP, DBP and pulse pressure at the age of 40, on carotid plaque burden, echolucent plaques and carotid intima-media thickness late midlife.

METHODS

Individuals participating in two separate studies, 23 years apart, defined our cohort (n = 2714). 'The Age 40 Program', a nationwide Norwegian cardiovascular screening survey, performed 1985-1999, assessed cardiovascular risk factors and lifestyle variables at age 40. 'The ACE 1950 Study', a population-based cohort study on individuals born in 1950, performed 2012-2015, included ultrasound examinations of the carotid arteries. Blood pressure (BP) determinants of carotid atherosclerosis were assessed by regression models adjusted for cardiovascular risk factors at age 40, and late midlife BP.

RESULTS

The participants, 50.3% women, had a mean age of 40 (SD 0.3) years in the first study, and 64 (SD 0.6) years in the second. At age 40, mean SBP was 128 (SD 14) mmHg, mean DBP was 78 (SD 10) mmHg and mean pulse pressure was 50 (SD 9) mmHg. SBP and DBP at age 40 predicted carotid plaque burden in late midlife. Only DBP predicted echolucent plaques, and none of the BP components predicted carotid intima-media thickness.

CONCLUSION

A single time-point measurement of SBP and DBP at age 40 is associated with carotid plaque burden late midlife, also after adjustment for other cardiovascular risk factors at age 40, and of late midlife BP. Our findings emphasize the strong association between BP and atherosclerosis.

Implication of ultrasound contrast-enhancement of carotid plaques in prevalence of acute coronary syndrome and occurrence of cardiovascular outcomes

PURPOSE

Ultrasonographic contrast enhancement of carotid plaque (CECP) has been used to detect neovascularization of vasa vasorum and plaque. However, it is uncertain whether CECP can provide risk stratification of coronary artery disease (CAD). This study aimed to evaluate the relationship between CECP and manifestations of acute coronary syndrome (ACS) in established CAD patients and to explore the prognostic implication of CECP for cardiovascular (CV) clinical outcomes.

METHODS

A medical record review revealed that contrast-enhanced ultrasonography was performed to evaluate carotid atherosclerosis in 209 coronary artery-stented and 105 non-stented patients. The rate of ACS manifestations was compared depending on contrast uptake patterns: grade 0, absent; grade 1, dot; and grade 2, diffuse pattern. CV primary outcomes were assessed during a mean 7.6 months of follow-up.

RESULTS

Male sex, smoking, history of old myocardial infarction, intensive medications, and a favorable lipid profile were common in the stented versus non-stented group. Patients with grade 2 CECP had a higher rate of ACS, greater plaque thickness, and class I-II of Gray-Weale plaque echogenicity. During follow-up, 10 coronary revascularizations (nine ACSs), six strokes, and four heart failures occurred. Grade 2 CECP was more closely related with CV primary outcomes and showed a tendency toward more acute CV outcomes.

CONCLUSION

ACS manifestations were proportionate to CECP grade. Diffuse CECP uptake could be a risk factor for acute CV outcomes.

Three-Dimensional Echographic Evaluation of Carotid Artery Disease

The introduction of three-dimensional echography (3D echo) in vascular field is not recent, but it still remains a seldom-used technique because of the costs of ultrasound probe and the need of dedicated laboratories. Therefore, despite significant prognostic implications, the high diagnostic accuracy in plaque definition, and the relative ease of use, 3D echo in vascular field is a niche technique. The purpose of this review is mainly clinical and intends to demonstrate the potential strength of a 3D approach, including technical aspects, in order to present to clinicians and imagers the appealing aspects of a noninvasive and radiation-free methodology with relevant diagnostic and prognostic correlates in the assessment of carotid atherosclerosis. A comprehensive literature search (since 1990s to date) using the PubMed, MEDLINE, and Cochrane libraries databases has been conducted. Articles written in English have been assessed, including reviews, clinical trials, meta-analyses, and interventional/observational studies. Manual cross-referencing was also performed, and relevant references from selected articles were reviewed. The search was limited to studies conducted in humans. Search terms, retrieved also with PubMed Advanced search and AND/OR Boolean operators (mainly in title and abstract), included three-dimensional, echo, stroke/transient ischemic attack, predictors, carotid, imaging, and biomarkers.

[Contribution of contrast enhanced ultrasonography in the characterization of carotid lesions]

Harmonic mode ultrasound with injection of a contrast enhancement agent allows visualization of mobile microbubbles in the carotid plaque corresponding to neovessels secondary to an inflammation or hypoxia. These neovessels could be considered "precursor" markers of the vulnerable plaque. The aim of this work was to give an update on ultrasound contrast imaging acquisition in the exploration of carotid artery both for atheromatous lesions and for large vessel vasculitis. A precise description of the material to be used, the image acquisition methodology and the environmental conditions is discussed, emphasizing the pitfalls to be avoided as well as proper image interpretation. Microbubbles in a plaque are significantly associated with an increase in cardiovascular events (infarction and acute coronary syndrome) and ipsilateral cerebral ischemic events. Wall irregularities, microfissures and ulcer plaque detection are facilitated by the use of contrast compared to the CT scan. No studies have yet validated contrast enhanced ultrasound in the exploration of asymptomatic carotid stenosis. Contrast enhanced ultrasound also allows to detect vasculitis of the large vessels active phases by the presence of microbubbles in the carotid wall thickening and to monitor the regression under appropriate medical treatment. Future validation studies or even registries are needed to allow better use of this tool in everyday clinical practice.

Pre-operative Carotid Plaque Echolucency Assessment has no Predictive Value for Long-Term Risk of Stroke or Cardiovascular Death in Patients Undergoing Carotid Endarterectomy

INTRODUCTION

In patients with carotid stenosis receiving medical treatment, carotid plaque echolucency has been thought to predict risk of future stroke and of other cardiovascular events. This study evaluated the prognostic value of pre-operative plaque echolucency for future stroke and cardiovascular death in patients undergoing carotid endarterectomy in the first Asymptomatic Carotid Surgery Trial (ACST-1).

METHODS

In ACST-1, 1832/3120 patients underwent carotid endarterectomy (CEA), of whom 894 had visual echolucency assessment according to the Gray-Weale classification. During follow-up patients were monitored both for peri-procedural (i.e. within 30 days) death, stroke, or MI, and for long-term risk of stroke or cardiovascular death. Unconditional maximum likelihood estimation was used to calculate odds ratios of peri-procedural risk and Kaplan-Meier statistics with log-rank test were used to compare cumulative long-term risks.

RESULTS

Of 894 operated patients in whom echolucency was assessed, 458 plaques (51%) were rated as echolucent and peri-procedural risk of death/stroke/MI in these patients was non-significantly higher when compared with patients with non-echolucent plaques (OR 1.48 [95% CI 0.76-2.88], p = .241). No differences were found in the 10 year risk of any stroke (30/447 [11.6%] vs. 29/433 [11.0%], p = .900) or cardiovascular (non-stroke) death (85/447 [27.9%] vs. 93/433 [32.1%], p = .301).

CONCLUSION

In ACST-1, carotid plaque echolucency assessment in patients undergoing CEA offered no predictive value with regard to peri-operative or long-term stroke risk or of cardiovascular (non-stroke) death.

Unstable carotid artery plaque: new insights and controversies in diagnostics and treatment

Cardiovascular disease is estimated to be the leading cause of death, globally causing 14 million deaths each year. Stroke remains a massive public health problem and there is an increasing need for better strategies for the prevention and treatment of this disease. At least 20% of ischemic strokes are thromboembolic in nature, caused by a thromboembolism from an atherosclerotic plaque at the carotid bifurcation or the internal carotid artery. Current clinical guidelines for both primary and secondary prevention of stroke in patients with carotid stenosis caused by atherosclerotic plaques remain reliant on general patient characteristics (traditional risk factors for stroke) and static measures of the degree of artery stenosis. Patients with similar traditional risk factors, however, have been found to have different risk of stroke, and it has in recent years become increasingly clear that the degree of artery stenosis alone is not the best estimation of stroke risk. There is a need for new methods for the assessment of stroke risk to improve risk prediction for the individual patient. This review aims to give an overview of new methods available for the identification of carotid plaque instability and the assessment of stroke risk.

Atherosclerotic plaque burden of middle cerebral artery and extracranial carotid artery characterized by MRI in patients with acute ischemic stroke in China: association and clinical relevance

OBJECTIVES

This study sought to compare the atherosclerotic plaque burden between middle cerebral artery (MCA) and extracranial carotid artery (ECA) in ischemic stroke patients using high-resolution, black-blood (HR BB) MRI and to investigate the relationship between plaque burden found in both arteries and stroke severity.

METHODS

All subjects with recent ischemic stroke underwent MCA and ECA HR BB MRI at 3.0 Tesla. For each artery segment, the thickness, area and signal intensities of plaques were recorded. Plaque burden, as measured by normalized wall index (NWI = wall area/total vessel area × 100%) were calculated. All patients received a clinical stroke severity score as measured by the National Institutes of Health Stroke Scale (NIHSS) scores at the time of admission.

RESULTS

A total of 65 stroke subjects were included in the final analysis. MCA exhibited significantly greater NWI than the ipsilateral ECA (symptomatic MCA vs. ECA: 58.04 ± 8.19 vs. 37.53 ± 10.25, p < 0.001; asymptomatic MCA vs. ECA: 53.80 ± 4.49 vs. 34.85 ± 4.27, p < 0.001, respectively). NWI in symptomatic MCA and ECA were significantly associated with NIHSS scores (r = 0.779 vs. 0.645; p < 0.001 respectively). Moreover, stronger statistical correlations between NIHSS scores and NWI were found in MCA, as compared with ECA during multivariate linear regression analysis.

CONCLUSION

Greater atherosclerotic plaque burden and a closer association with stroke severity were found for the MCA as compared to the ipsilateral ECA. Identification of MCA plaque lesions by MRI may be helpful for developing more aggressive strategies for stroke prevention.

Imaging Carotid Atherosclerosis Plaque Ulceration: Comparison of Advanced Imaging Modalities and Recent Developments

Atherosclerosis remains the leading cause of long-term mortality and morbidity worldwide, despite remarkable advancement in its management. Vulnerable atherosclerotic plaques are principally responsible for thromboembolic events in various arterial territories such as carotid, coronary, and lower limb vessels. Carotid plaque ulceration is one of the key features associated with plaque vulnerability and is considered a notable indicator of previous plaque rupture and possible future cerebrovascular events. Multiple imaging modalities have been used to assess the degree of carotid plaque ulceration for diagnostic and research purposes. Early diagnosis and management of carotid artery disease could prevent further cerebrovascular events. In this review, we highlight the merits and limitations of various imaging techniques for identifying plaque ulceration.

Plaque surface irregularity and calcification length within carotid plaque predict secondary events in patients with coronary artery disease

BACKGROUND AND AIMS

Although comprehensive risk factor modification is recommended, a uniform management strategy does not necessarily prevent secondary events in patients with coronary artery disease (CAD). Therefore, identification of high-risk patients who may benefit from more intensive interventions may improve prognosis. Carotid ultrasound can reliably identify systemic atherosclerosis, and carotid plaque and intima-media thickness (IMT) are known independent risk factors for CAD. However, it is unclear whether findings on carotid ultrasound can improve prediction of secondary CAD events.

METHODS

The study population comprised 146 consecutive patients with CAD (mean age, 66 ± 9 years; 126 with angina pectoris, 20 with acute myocardial infarction). IMT, plaque score, plaque area, plaque surface irregularity, and calcification length (calculated by summing the calcified lesions within each plaque accompanied by acoustic shadow) were measured at baseline. Patients were followed for 10 years to ascertain secondary CAD events defined as hard major adverse cardiovascular events (MACE; cardiac death and acute myocardial infarction) and as total MACE (hard MACE and angina pectoris with coronary revascularization).

RESULTS

Multiple regression analysis demonstrated that calcification length (p < 0.05) and plaque surface irregularity (p < 0.01) remained independently associated with total MACE after adjustment for age, sex, diabetes mellitus, dyslipidemia, hypertension, chronic kidney disease, smoking, and multivessel CAD.

CONCLUSIONS

These findings suggest that the combination of calcification length and plaque surface irregularity has additional value beyond traditional risk classification. Intensive intervention for these high-risk patients may avoid or delay progression of atherosclerosis towards secondary CAD events.

Plaque Composition in the Proximal Superficial Femoral Artery and Peripheral Artery Disease Events

OBJECTIVES

The aim of this study was to describe associations of the presence of lipid-rich necrotic core (LRNC) in the proximal superficial femoral artery (SFA) with lower extremity peripheral artery disease (PAD) event rates and systemic cardiovascular event rates.

BACKGROUND

LRNC in the coronary and carotid arteries is associated with adverse outcomes but has not been studied previously in lower extremity arteries.

METHODS

Participants with ankle-brachial index (ABI) values <1.00 were identified from Chicago medical centers and followed annually. Magnetic resonance imaging was used to characterize SFA atherosclerotic plaque at baseline. Medical records for hospitalizations and procedures after baseline were adjudicated for lower extremity revascularization, amputation, and critical limb ischemia and also for new coronary events, ischemic stroke, and mortality.

RESULTS

Of 254 participants with PAD, 62 (24%) had LRNC and 149 (59%) had calcium in the SFA at baseline. Cox regression analyses were adjusted for age, sex, race, comorbidities, baseline ABI, and other confounders. SFA LRNC was associated with an increased incidence of the combined outcome of lower extremity amputation, critical limb ischemia, ABI decline >0.15, and revascularization at 47-month follow-up (hazard ratio: 2.18; 95% confidence interval: 1.27 to 3.75; p = 0.005). The association of SFA LRNC with PAD events was maintained even when this combined outcome excluded lower extremity revascularization (hazard ratio: 2.58; 95% confidence interval: 1.25 to 5.33; p = 0.01). LRNC in the SFA was not associated with all-cause mortality, acute coronary events, or stroke.

CONCLUSIONS

Among patients with PAD, LRNC in the SFA was associated with higher rates of clinical PAD events, and this association was independent of ABI. Further study is needed to determine whether interventions that reduce SFA LRNC prevent PAD events.

Evaluation of carotid arteries in stroke patients using color Doppler sonography: A prospective study conducted in a tertiary care hospital in South India

Aims and Objectives:

Cerebral ischemic stroke is life-threatening and debilitating neurological disease, it is the third leading cause of death in the world. Studies have shown that there is a close relationship between carotid artery stenosis and ischemic cerebral vascular disease. This study is done to assess the carotid arteries with the help of color Doppler sonography and to correlate cerebrovascular accidents.

Materials and Methods:

The prospective study was carried out on 50 patients using purposive sampling technique. Risk factors such as hypertension, diabetes mellitus, smoking, and family history were documented. The data gathered from color Doppler examination consisted of peak systolic velocity of common carotid artery (CCA) and internal carotid artery (ICA), velocity ratios between CCA and ICA and plaque characteristics as seen on real-time image.

Statistical Analysis Used:

The collected data were analyzed and presented in the form of tables, figures, graphs, and diagrams wherever necessary. As this study deals with the only frequency distribution of various factors, so no tests of significance were applied.

Results:

The highest incidence of stroke was found in the male population in the age group of 60–69 years. Various risk factors included hypertension, diabetes mellitus, smoking, and family history. Of 50 patients, 12 patients showed significant stenosis (>60%). Atherosclerotic plaques were seen in 39 patients (78%).

Conclusion:

Color Doppler examination is an economic, safe, reproducible, and less time-consuming method of demonstrating the cause of cerebrovascular insufficiency in extracranial carotid artery system and will guide in instituting treatment modalities.

Impact of Cardiovascular Risk Factors on Carotid Intima-Media Thickness and Degree of Severity: A Cross-Sectional Study

Objective

Age, hypertension, dyslipidemia and diabetes are common cardiovascular risk factors (CVRFs) that contribute to the development of atherosclerosis in cardiovascular system including carotid artery disease. However, the impact of these risk factors on the increased carotid intima-media thickness (cIMT) and degree of carotid severity remains to be further clarified. This study aims to evaluate the relationship between CVRFs and degree of carotid severity and cIMT in high-risk subjects.

Methods

Four thousand and three hundred ninety-four subjects with one or more risk factors were retrospectively reviewed in this study. Patients were divided into different groups based on age, the type and quantity of CVRFs. cIMT and degree of carotid artery stenosis were measured and analyzed based on carotid ultrasound imaging with findings compared to the CVRFs to determine the correlation between these variables.

Results

Aging was significantly associated with degree of severity (P < 0.05) and cIMT was significantly increased with age (P < 0.05). Individual CVRF analysis shows that hypertension was more related to the degree of severity than dyslipidemia and diabetes with corresponding abnormal cIMT rates being 79.39%, 72.98% and 32.37%, respectively. The prevalence of carotid atherosclerosis were 20.06%, 22.88% and 28.63%, respectively corresponding to patients with zero, one and more than one chronic diseases. The percentage of abnormal cIMT in hypertensive patient group with dyslipidemia is significantly higher than the other groups (P< 0.05).

Conclusions

This study shows a direct correlation between the degree of carotid severity and cIMT and cardiovascular risk factors, especially with age and hypertension. Carotid atherosclerosis is closely related to the number of cardiovascular risk factors.

Morphologic Features of Carotid Plaque Rupture Assessed by Optical Coherence Tomography

BACKGROUND AND PURPOSE

Rupture of the plaque fibrous cap and subsequent thrombosis are the major causes of stroke. This study evaluated morphologic features of plaque rupture in the carotid artery by using optical coherence tomography in vivo.

MATERIALS AND METHODS

Thirty-six carotid plaques with high-grade stenosis were prospectively imaged by optical coherence tomography. "Plaque rupture" was defined as a plaque containing a cavity that had overlying residual fibrous caps. The fibrous cap thickness was measured at its thinnest part for both ruptured and nonruptured plaques. The distance between the minimum fibrous cap thickness site and the bifurcation point was also measured. Optical coherence tomography identified 24 ruptured and 12 nonruptured plaques.

RESULTS

Multiple ruptures were observed in 9 (38%) patients: Six patients had 2 ruptures in the same plaque, 2 patients had 3 ruptures in the same plaque, and 1 patient had 5 ruptures in the same plaque. Most (84%) of the fibrous cap disruptions were identified at the plaque shoulder and near the bifurcation point (within a 4.2-mm distance). The median thinnest cap thickness was 80 μm (interquartile range, 70-100 μm), and 95% of ruptured plaques had fibrous caps of <130 μm. Receiver operating characteristic analysis revealed that a fibrous cap thickness of <130 μm was the critical threshold value for plaque rupture in the carotid artery.

CONCLUSIONS

Plaque rupture was common in high-grade stenosis and was located at the shoulder of the carotid plaque close to the bifurcation. A cap thickness of <130 μm was the threshold for plaque rupture in the carotid artery.

Incidence, outcome, risk factors, and long-term prognosis of cryptogenic transient ischaemic attack and ischaemic stroke: a population-based study

Background

A third of transient ischaemic attacks (TIAs) and ischaemic strokes are of undetermined cause (ie, cryptogenic), potentially undermining secondary prevention. If these events are due to occult atheroma, the risk-factor profile and coronary prognosis should resemble that of overt large artery events. If they have a cardioembolic cause, the risk of future cardioembolic events should be increased. We aimed to assess the burden, outcome, risk factors, and long-term prognosis of cryptogenic TIA and stroke.

Methods

In a population-based study in Oxfordshire, UK, among patients with a first TIA or ischaemic stroke from April 1, 2002, to March 31, 2014, we compared cryptogenic events versus other causative subtypes according to the TOAST classification. We compared markers of atherosclerosis (ie, risk factors, coronary and peripheral arterial disease, asymptomatic carotid stenosis, and 10-year risk of acute coronary events) and of cardioembolism (ie, risk of cardioembolic stroke, systemic emboli, and new atrial fibrillation [AF] during follow-up, and minor-risk echocardiographic abnormalities and subclinical paroxysmal AF at baseline in patients with index events between 2010 and 2014).

Findings

Among 2555 patients, 812 (32%) had cryptogenic events (incidence of cryptogenic stroke 0·36 per 1000 population per year, 95% CI 0·23–0·49). Death or dependency at 6 months was similar after cryptogenic stroke compared with non-cardioembolic stroke (23% vs 27% for large artery and small vessel subtypes combined; p=0·26) as was the 10-year risk of recurrence (32% vs 27%; p=0·91). However, the cryptogenic group had fewer atherosclerotic risk factors than the large artery disease (p<0·0001), small vessel disease (p=0·001), and cardioembolic (p=0·008) groups. Compared with patients with large artery events, those with cryptogenic events had less hypertension (adjusted odds ratio [OR] 0·41, 95% CI 0·30–0·56; p<0·0001), diabetes (0·62, 0·43–0·90; p=0·01), peripheral vascular disease (0·27, 0·17–0·45; p<0·0001), hypercholesterolaemia (0·53, 0·40–0·70; p<0·0001), and history of smoking (0·68, 0·51–0·92; p=0·01), and compared with small vessel and cardioembolic subtypes, they had no excess risk of asymptomatic carotid disease (adjusted OR 0·64, 95% CI 0·37–1·11; p=0·11) or acute coronary events (adjusted hazard ratio [HR] 0·76, 95% CI 0·49–1·18; p=0·22) during follow-up. Compared with large artery and small vessel subtypes combined, patients with cryptogenic events also had no excess of minor-risk echocardiographic abnormalities (cryptogenic 37% vs 45%; p=0·18) or paroxysmal AF (6% vs 10%; p=0·17) at baseline or of new AF (adjusted HR 1·23, 0·78–1·95; p=0·37) or presumed cardioembolic events (1·16, 0·62–2·17; p=0·64) during follow-up.

Interpretation

The clinical burden of cryptogenic TIA and stroke is substantial. Although stroke recurrence rates are comparable with other subtypes, cryptogenic events have the fewest atherosclerotic markers and no excess of cardioembolic markers.

Funding

Wellcome Trust, Wolfson Foundation, UK Stroke Association, British Heart Foundation, Dunhill Medical Trust, National Institute for Health Research, Medical Research Council, and the NIHR Oxford Biomedical Research Centre.

Expression of the genes encoding kinin receptors are increased in human carotid atherosclerotic plaques

There is increasing evidence showing that inflammation occurs in atherosclerosis and contributes to the formation of atherosclerotic plaques. As important inflammatory peptides, kinins are increased in inflammation, eliciting vasodilation, increasing vascular permeability and recruiting inflammatory cells to the injury sites by activating specific receptors, B1 and B2. The two receptors have been reported to increase in inflammation, but their expressions remain to be defined in human carotid atherosclerotic plaques (CAP). In order to assess the gene expression of kinin receptors in human CAP, 47 CAP specimens were collected from patients undergoing endarterectomy and classified into stable and unstable plaque groups, respectively, with 10 mesenteric arteries used as controls. Total mRNA of B1R and B2R was extracted from CAPs and their levels were determined using reverse transcription-polymerase chain reaction. The expression of B1R and B2R mRNA was significantly upregulated in human CAPs compared to the control arteries. In the unstable plaques, the ratios of B1R to the β-actin mRNA level were significantly increased relative to the stable plaques. However, no notable differences were observed in the ratios of B2R to β-actin in mRNA expression between the stable and unstable plaques. The present study suggests that kinin-mediated inflammation involves the formation of atherosclerotic plaque and B1R plays an important role in plaque instability, indicating that kinin receptors can be used as potential targets for future therapeutic interventions.

Assessment of carotid plaque neovascularization using quantitative analysis of contrast-enhanced ultrasound imaging is useful for risk stratification in patients with coronary artery disease

BACKGROUND

Contrast-enhanced ultrasound (CEUS) of the carotid artery is a potential technique for imaging plaque neovascularization, a feature of unstable atherosclerotic plaques. This study examined whether assessment of intra-plaque neovascularization of the carotid artery using CEUS provides prognostic information in patients with coronary artery disease (CAD).

METHODS

A total of 206 patients with stable CAD underwent a CEUS examination of the carotid artery and were followed up prospectively for <38 months or until a cardiac event (cardiac death, non-fatal myocardial infarction (MI), unstable angina pectoris (uAP) requiring unplanned coronary revascularization, or heart failure requiring hospitalization). The degree of contrast signals measured within the carotid plaque was quantified by calculating the mean gray scale level within the region of interest of the carotid plaque, expressed as plaque enhanced intensity.

RESULTS

During the follow-up period, 31 events occurred (2 cardiac deaths, 7 non-fatal MIs, 16 uAP, and 6 heart failure). Multivariate Cox proportional hazard analysis showed that plaque enhanced intensity was a significant predictor of cardiac events independent of traditional risk factors (HR, 1.13; 95% CI, 1.05-1.21; p<0.001). The addition of the plaque enhanced intensity to traditional risk factors resulted in net reclassification improvement (NRI) and integrated discrimination improvement (IDI) (NRI 0.62, p=0.001; and IDI 0.106, p=0.002).

CONCLUSIONS

The assessment of carotid plaque neovascularization using quantitative analysis of CEUS may be useful for risk stratification in patients with CAD.

Echolucent Carotid Plaque is Associated with Future Renal Dysfunction in Patients with Stable Coronary Artery Disease

AIM

Functional and structural abnormalities of the peripheral arteries are associated with renal dysfunction, independent of the presence of renal artery stenosis. This study investigated whether echolucent carotid plaque is associated with a future decline in the renal function in patients with coronary artery disease (CAD).

METHODS

Ultrasound assessments of carotid plaque echolucency with integrated backscatter (IBS) analyses were performed in 327 patients with stable CAD and carotid plaque who exhibited a normal renal function (estimated glomerular filtration rate [eGFR] ≥60 mL/min/1.73 m(2)) at baseline. A lower IBS value reflects the presence of echolucent and lipid-rich unstable plaque. All patients were followed up for 36 months or until the occurrence of renal dysfunction, defined as an eGFR of ＜45 mL/min/1.73 m(2).

RESULTS

During the follow-up period, 39 patients developed renal dysfunction. A multivariate logistic regression analysis showed that the presence of carotid plaque with a low IBS value was significantly associated with progression to renal dysfunction (odds ratios 0.48; 95% CI 0.30-0.78, p= 0.003). In addition, carotid plaque with a low IBS value had a significant incremental effect on the predictive value of known risk factors for renal dysfunction in analyses using c-statistics (AUC of the baseline risk model with and without IBS: 0.83 vs. 0.79, respectively, p=0.04), net reclassification improvement (index=0.549, p=0.001) and integrated discrimination improvement (index=0.068, p=0.002).

CONCLUSIONS

Echolucency of the carotid arteries is associated with future renal dysfunction in patients with stable CAD, indicating that the mechanisms related to plaque instability may be involved in the onset of renal dysfunction.

Detection of carotid artery stenosis: a comparison between 2 unenhanced MRAs and dual-source CTA

BACKGROUND AND PURPOSE

Dual-source CTA and black-blood MRA are recently developed techniques for evaluating carotid stenosis. The purpose of this study was to compare dual-source CTA with black-blood MRA and conventional TOF MRA in both detecting carotid stenosis by using DSA as a reference standard and demonstrating plaque morphology.

MATERIALS AND METHODS

Thirty patients with suspected carotid artery stenosis underwent unenhanced MRA by using black-blood and TOF MRA and dual-source CTA. Source images from unenhanced MRAs and dual-source CTA were reconstructed with MIP or curved planar reconstruction. The degree of carotid artery stenosis was measured, and plaque surface morphology at the stenosis was analyzed and compared among different techniques.

RESULTS

Good correlation was observed for measuring the degree of carotid stenosis among dual-source CTA, black-blood MRA, TOF MRA, and DSA. Sensitivity and specificity for detecting severe stenosis were 100% and 97% with dual-source CTA, 100% and 95% with black-blood MRA, and 79% and 95% with TOF MRA. None of the 3 technologies resulted in stenosis of <50% being overestimated. Plaque surface irregularity or ulceration was more frequently detected with dual-source CTA and black-blood MRA than with TOF MRA and DSA.

CONCLUSIONS

This preliminary study shows that black-blood MRA is a promising technique, comparable with dual-source CTA and DSA, but better than TOF MRA, in the evaluation of carotid stenosis. Unlike dual-source CTA, black-blood MRA requires no intravenous contrast or radiation.