Non-invasive assessments reveal that more than half of randomly selected middle-aged individuals have evidence of subclinical atherosclerosis: a DanRisk substudy

Reduced radiation dose and volume of contrast medium in heart rate-based, one-stop computed tomography angiography of coronary, carotid and cerebrovascular arteries

BACKGROUND

Computed tomography angiography (CTA) is a reliable, non-invasive screening method for diagnosing panvascular disease. By using low contrast agent volume, CTA imaging enables one-stop multi-organ scanning, thereby minimizing the potential risk of contrast-induced nephropathy in patients with impaired renal function.

PURPOSE

To evaluate the feasibility of one-stop CTA following a heart rate (HR)-based protocol using a low volume of contrast medium (CM) for examination of the coronary, carotid and cerebrovascular arteries.

MATERIAL AND METHODS

Sixty patients undergoing coronary carotid, and cerebrovascular CTA after a single injection of CM were recruited and randomly divided into two groups. Group A (n = 30) underwent CTA following a traditional protocol. The timing of the scans in Group B (n = 30) was determined according to the patient's HR.

RESULTS

The CT values for the thoracic aorta (432.2 ± 104.28 HU), anterior cerebral artery (303.96 ± 99.29 HU), and right coronary artery (366.70 ± 85.10 HU) in Group A did not differ significantly from those in Group B (445.80 ± 106.13, 293.73 ± 75.25 and 344.13 ± 111.04 HU, respectively). The qualities of most of the scanned images for both groups were scored as 3 or 4 (on a five-point scale). The radiation dose and the volume of CM were significantly higher in Group A (303.05 ± 110.95 mGy) (100 mL) than in Group B (239.46 ± 101.12 mGy) (50 mL).

CONCLUSION

The radiation dose and volume of CM were significantly reduced in CTA following the HR-based protocol. The personalized administration of CM also simplified the scanning process.

Incremental Value of Noncontrast Chest Computed Tomography-derived Parameters in Predicting Subclinical Carotid Atherosclerosis: From the PERSUADE Study

PURPOSE

To investigate the incremental value of noncontrast chest computed tomography (CT)-derived parameters, such as coronary artery calcium score (CACS) and epicardial adipose tissue volume (EATv), in predicting subclinical carotid atherosclerosis above traditional risk factors in community-based asymptomatic populations of northern China.

MATERIALS AND METHODS

A total of 2195 community-based asymptomatic individuals were enrolled from Jidong Oilfield in accordance with the PERSUADE study. CACS and EATv were measured on noncontrast chest CT. Demographics and ideal cardiovascular health score (ICHS) were collected through questionnaires. We recalculated the ideal cardiovascular health risk score (ICHRS) (ICHRS=14-ICHS) and standardized the parameters as log-CACS and body mass index adjusted EATv (i-EATv). Subclinical carotid atherosclerosis was assessed by Doppler sonography and defined as any prevalence of average carotid intima-media thickness ≥1.00 mm, appearance of carotid plaque, and carotid arterial stenosis in the areas of extracranial carotid arteries on both sides.

RESULTS

A total of 451 (20.55%) individuals presented subclinical carotid atherosclerosis. CACS and EATv were significantly greater in the subclinical group, while ICHS was lower. In multivariate logistic regression, ICHRS (odds ratio [OR]=1.143, 95% confidence interval [CI]: 1.080-1.210, P <0.001), log-CACS (OR=1.701, 95% CI: 1.480-1.955, P <0.001), and i-EATv (OR=1.254, 95% CI: 1.173-1.341, P <0.001) were found to be independent risk predictors for subclinical carotid atherosclerosis. In receiver-operating characteristic curve analysis, when combined with male sex and age level, the area under the curve of the ICHRS basic model increased from 0.627 (95% CI: 0.599-0.654) to 0.757 (95% CI: 0.732-0.781) ( P <0.0001). Further adding log-CACS and i-EATv, the area under the curve demonstrated a statistically significant improvement (0.788 [95% CI: 0.765-0.812] vs. 0.757 [95% CI: 0.732-0.781], P <0.0001).

CONCLUSION

Noncontrast chest CT-derived parameters, including CACS and EATv, could provide significant incremental improvement for predicting subclinical carotid atherosclerosis beyond the conventional risk assessment model based on ICHRS.

Imaging-guided evaluation of subclinical atherosclerosis to enhance cardiovascular risk prediction in asymptomatic low-to-intermediate risk individuals: A systematic review

Carotid intima-media thickness (cIMT), plaque quantification and coronary artery calcium (CAC) scoring have been suggested to improve risk prediction of cardiovascular disease (CVD), particularly for asymptomatic individuals classified as low-to-intermediate risk. We aimed to compare the predictive value of cIMT, carotid plaque identification, and CAC scoring for identifying sub-clinical atherosclerosis and assessing future risk of CVD in asymptomatic, low-to-intermediate risk individuals. We conducted a comprehensive search of Ovid (Embase and Medline), Cochrane Central Register of Controlled Trials (CENTRAL) and Medline complete (EBSCO health). A total of 30 papers were selected and data were extracted. Comparisons were made according to the cIMT measurement (mean, maximum), carotid plaque evaluation (presence or area), and CAC scoring. CVD event rates, hazard ratios (HR), net reclassification index (NRI), and c-statistic of the markers were compared. There were 27 studies that reported cIMT, 24 reported carotid plaque, and 6 reported CAC scoring. Inclusion of CAC scores yielded the highest HR ranging from 1.45 (95% CI, 1.11-1.88, p = 0.006) to 3.95 (95% CI, 2.97-5.27, p < 0.001), followed by maximum cIMT (HR 1.08; 95% CI, 1.06-1.11, p < 0.001 to 2.58; 95% CI, 1.83-3.62, p < 0.001) and carotid plaque presence (HR 1.21; 95% CI, 0.5-1.2, p = 0.39 to 2.43; 95% CI, 1.7-3.47, p < 0.001). The c-statistic enhanced predictive value by a minimum increase of 0.7. Finally, the NRI ranked higher with CAC (≥11.2%), followed by carotid plaque (≥2%) and cIMT (3%). CAC scoring was superior compared to carotid plaque and cIMT measurements in asymptomatic individuals classified as being at low-to-intermediate risk.

Carotid plaque composition by CT angiography in asymptomatic subjects: a head-to-head comparison to ultrasound

OBJECTIVES

To describe carotid plaque composition by computed tomography angiography (CTA) in asymptomatic subjects and to compare this to carotid plaque assessment by ultrasound, coronary plaques by coronary CTA, and inflammatory biomarkers in plasma.

METHODS

Middle-aged asymptomatic men, n = 43, without known cardiovascular disease and diabetes were included. Plaques in coronary and carotid arteries were evaluated using CTA. Total plaque volumes and plaque composition were assessed by a validated plaque analysis software. The 60% centile cut point was used to divide the population into low or high carotid total plaque volumes. The occurrence of carotid plaques and intima-media thickness (IMT) was estimated by ultrasound.

RESULTS

Carotid plaque by ultrasound was undiagnosed in 13 of 28 participants (46%) compared to CTA. Participants having carotid plaques by ultrasound had significantly higher absolute volumes of all CTA-defined carotid plaque subtypes and a higher fraction of calcified plaque. A high carotid total plaque volume was independently associated with age (adjusted odds ratio (OR) 1.41 [95% confidence interval (CI) 1.14-1.74], p = 0.001), IMT (adjusted OR 2.26 [95% CI 1.10-4.65], p = 0.03), and D-dimer (adjusted OR 8.86 [95% CI 1.26-62.37], p = 0.03). All coronary plaque features were significantly higher in participants with a high carotid total plaque volume.

CONCLUSION

The occurrence of carotid plaques in asymptomatic individuals is underestimated by ultrasound compared to plaque assessment by CTA. Carotid plaque composition by CTA is different in individuals with and without carotid plaques by ultrasound.

KEY POINTS

• The occurrence of carotid plaques by ultrasound was underestimated in 46% of participants who had plaques by carotid CTA. • Participants with carotid plaques by ultrasound had higher volumes of all plaque subtypes and a higher calcified plaque component as determined by carotid CTA compared to participants without carotid plaques by ultrasound. • A high carotid total plaque volume was independently associated with age, intima-media thickness, and D-dimer.

Sex difference in fibrin clot lysability: Association with coronary plaque composition

INTRODUCTION

Fibrin clot lysability is associated with development of cardiovascular disease (CVD). We evaluated sex-differences in fibrin clot lysability and the association with coronary plaque composition determined by computed tomography angiography (CTA).

METHODS

Middle-aged citizens without known CVD were randomly selected from a national registry. A coronary CTA assessed volumes of calcified-, non-calcified-, low-density non-calcified-, and total- plaque using a validated plaque quantification software. A non-enhanced cardiac CT scan assessed the Agatston score. Fibrin structure properties were determined using turbidimetric methods. Plasma concentrations of C-reactive protein and fibrinogen were assessed.

RESULTS

138 individuals (71 women) participated. Men more frequently had coronary plaques compared to women, P < 0.05. Coronary plaque features were comparable between men and women, P > 0.05. Women with total plaque volume > 0 mm³ had lower fibrin clot lysability compared to women with total plaque volume = 0 mm³, adjusted difference [95% confidence interval] 10.28 [1.42-19.15], P = 0.02, and a fibrinogen-dependent lower fibrin clot lysability compared to men with and without coronary plaques, 6.82 [-2.67-16.31], P = 0.16, and 8.73 [-0.43-17.89], P = 0.06, respectively. Fibrinogen correlated with all the coronary plaque features (correlation coefficient r = 0.42-0.57) only in women with total plaque volume > 0 mm³, all P < 0.01.

CONCLUSION

Asymptomatic women with coronary plaques assessed by coronary CTA have reduced fibrin clot lysability compared to both women without coronary plaques and men, suggesting a sex-dependent link between coronary atherosclerosis and fibrin clot lysability.

Sex difference in clot lysability and association to coronary artery calcification

Background

Incidence and prevalence of cardiovascular disease (CVD) differ between sexes, and women experience CVD later than men. Changes in fibrin clot lysability are associated with CVD, and the present study addresses sex differences in fibrin clot lysability in asymptomatic middle-aged individuals and the relation to coronary artery calcification (CAC).

Methods

Participants free of morbidities and medication, N = 163, were randomly chosen from a national registry among citizens, 50 or 60 years of age, and were followed for 5 years. CAC was determined by the Agatston (Ag) score both at baseline and at follow-up. Based on the changes in Ag, the population was divided into two groups: ΔAg = 0 U or ΔAg > 0 U. Fibrin clot analyses were based on turbidimetric methods.

Results

At baseline, 116 women and 97 men were included; 84 women and 79 men completed the 5-year follow-up (77%). Independently of covariates, women with ΔAg > 0 had reduced mean (SD) fibrin lysability at follow-up, 40.2% (15.9), both in comparison to baseline, 47.8% (20.4), p = 0.001, to women with ΔAg = 0 U, 51.2% (24.5), p = 0.028, and to men with ΔAg > 0 U, 54.4% (21.0), p = 0.002.

Conclusions

Fibrin clot lysability changes over time with considerable sex differences. Women with progression of CAC have reduced fibrin clot lysability compared to men, indicating a sex-specific association between morphological vessel wall changes and fibrin clot lysability.

Subclinical cardiovascular disease assessment and its relationship with cardiovascular risk SCORE in a healthy adult population: A cross-sectional community-based study

INTRODUCTION

The aim of this study is to evaluate the relationship and the accuracy of SCORE (Systematic Coronary Risk Evaluation Project) risk correlated to multiple methods for determining subclinical cardiovascular disease (CVD) in a healthy population.

MATERIAL AND METHODS

This cross-sectional study included 120 completely asymptomatic subjects, with an age range 35-75 years, and randomly selected from the general population. The individuals were evaluated clinically and biochemical, and the SCORE risk was computed. Subclinical atherosclerosis was assessed by various methods: carotid ultrasound for intima-media thickness (cIMT) and plaque detection; aortic pulse wave velocity (aPWV); echocardiography - left ventricular mass index (LVMI) and aortic atheromatosis (AA); ankle-brachial index (ABI).

RESULTS

SCORE mean value was 2.95±2.71, with 76% of subjects having SCORE <5. Sixty-four percent of all subjects have had increased subclinical CVD changes, and SCORE risk score was correlated positively with all markers, except for ABI. In the multivariate analysis, increased cIMT and aPWV were significantly associated with high value of SCORE risk (OR 4.14, 95% CI: 1.42-12.15, p=0.009; respectively OR 1.41, 95% CI: 1.01-1.96, p=0.039). A positive linear relationship was observed between 3 territories of subclinical CVD (cIMT, LVMI, aPWV) and SCORE risk (p<0.0001). There was evidence of subclinical CVD in 60% of subjects with a SCORE value <5.

CONCLUSIONS

As most subjects with a SCORE value <5 have subclinical CVD abnormalities, a more tailored subclinical CVD primary prevention program should be encouraged.

PET Imaging of Atherosclerotic Disease: Advancing Plaque Assessment from Anatomy to Pathophysiology

Atherosclerosis is a leading cause of morbidity and mortality. It is now widely recognized that the disease is more than simply a flow-limiting process and that the atheromatous plaque represents a nidus for inflammation with a consequent risk of plaque rupture and atherothrombosis, leading to myocardial infarction or stroke. However, widely used conventional clinical imaging techniques remain anatomically focused, assessing only the degree of arterial stenosis caused by plaques. Positron emission tomography (PET) has allowed the metabolic processes within the plaque to be detected and quantified directly. The increasing armory of radiotracers has facilitated the imaging of distinct metabolic aspects of atherogenesis and plaque destabilization, including macrophage-mediated inflammatory change, hypoxia, and microcalcification. This imaging modality has not only furthered our understanding of the disease process in vivo with new insights into mechanisms but has also been utilized as a non-invasive endpoint measure in the development of novel treatments for atherosclerotic disease. This review provides grounding in the principles of PET imaging of atherosclerosis, the radioligands in use and in development, its research and clinical applications, and future developments for the field.

Coronary, Carotid, and Lower-extremity Atherosclerosis and Their Interrelationship in Danish Patients with Systemic Lupus Erythematosus

OBJECTIVE

Atherosclerosis is highly prevalent among patients with systemic lupus erythematosus (SLE), but has been demonstrated predominantly in non-European SLE cohorts and few investigations have included more than 1 imaging modality. We aimed to investigate the prevalence of atherosclerosis in 3 frequently affected vascular territories, the coronary, carotid, and lower-extremity arteries, in a Danish, predominantly population-based SLE cohort.

METHODS

Patients with SLE without prior cardiovascular disease (CVD; n = 103) were screened for coronary artery calcification, carotid intima-media thickening and plaque, and abnormal ankle-brachial index by means of cardiac computed tomography, ultrasound of the carotid arteries, and ankle systolic blood pressure.

RESULTS

In patients with SLE, the prevalence of atherosclerosis in any vascular territory was 41%. The distribution of the atherosclerotic manifestations showed an overlap with 45% of the patients having involvement in more than 1 vascular territory. However, more than one-third of the patients with SLE with coronary, carotid, or lower-extremity atherosclerosis exclusively demonstrated this particular manifestation. Based on a multiple logistic regression model, age (p < 0.001), current smoking (p = 0.009), and the Systemic Lupus International Collaborating Clinics (SLICC; p = 0.008) were significant independent risk factors for atherosclerosis at any vascular territory.

CONCLUSION

Atherosclerosis is highly prevalent among Danish patients with SLE without prior CVD. Screening for atherosclerosis in 1 vascular territory is insufficient in diagnosing atherosclerosis in patients with SLE. In Danish patients with SLE, the presence of atherosclerosis was not only assigned to traditional CV risk factors, but also associated with SLICC.

Automatic Characterization of the Physiological Condition of the Carotid Artery in 2D Ultrasound Image Sequences Using Spatiotemporal and Spatiospectral 2D Maps

A novel method for characterizing and visualizing the progression of waves along the walls of the carotid artery is presented. The new approach is noninvasive and able to simultaneously capture the spatial and the temporal propagation of wavy patterns along the walls of the carotid artery in a completely automated manner. Spatiotemporal and spatiospectral 2D maps describing these patterns (in both the spatial and the frequency domains, resp.) were generated and analyzed by visual inspection as well as automatic feature extraction and classification. Three categories of cases were considered: pathological elderly, healthy elderly, and healthy young cases. Automatic differentiation, between cases of these three categories, was achieved with a sensitivity of 97.1% and a specificity of 74.5%. Two features were proposed and computed to measure the homogeneity of the spatiospectral 2D map which presents the spectral characteristics of the carotid artery wall's wavy motion pattern which are related to the physical, mechanical (e.g., elasticity), and physiological properties and conditions along the artery. These results are promising and confirm the potential of the proposed method in providing useful information which can help in revealing the physiological condition of the cardiovascular system.

Feasibility of low-dose contrast medium high pitch CT angiography for the combined evaluation of coronary, head and neck arteries

Purpose

To evaluate the image quality and radiation dose of combined heart, head, and neck CT angiography (CTA) using prospectively electrocardiography (ECG)-triggered high-pitch spiral scan protocol, compared with single coronary CTA.

Materials and Methods

151 consecutive patients were prospectively included and randomly divided into three groups. Group 1 (n = 47) underwent combined heart, neck, and head CTA using prospectively ECG-triggered high-pitch spiral (Flash) scan protocol with a single-phase intravenous injection of iodinated contrast and saline flush; Group 2 (n = 51) underwent single coronary CTA with Flash scan protocol; and Group 3 (n = 53) underwent single coronary CTA with prospective sequence scan protocol. All patients were examined on a dual source CT (Definition FLASH). The image quality was determined for each CT study.

Results

Patients of scanning protocol Group 1, 2, and 3 showed no significant differences in age, sex, heart rates, and BMI. Evaluation of coronary artery image quality showed comparable results in the three scanning protocol groups on a per patient-based analysis. In group 1, image quality was found to be sufficient to be diagnostic in all arterial segments of carotid arteries. The mean dose-length product (DLP) for group 1 was 256.3±24.5 mGy×cm and was significantly higher in comparison with group 2 (93.4±19.9 mGy×cm; p < 0.001). However, there was no significant difference of DLP between group 1 and group 3 (254.1±69.9 mGy×cm).

Conclusions

The combined heart, neck, and head arteries scan using prospectively electrocardiography (ECG)-triggered high-pitch spiral scan protocol in 1 single examination resulted in an excellent opacification of the aorta, the carotid arteries, and the coronary arteries and provided a good image quality with low radiation dose.

A new anti-ageing strategy focused on prevention of arterial ageing in the middle-aged population

Ageing is a progressive process that according to available knowledge cannot be effectively reversed, slowed or stopped. Here we propose a new anti-ageing approach that may lead to the design of effective therapeutic intervention. First, we hypothesize that the "organ system" oriented anti-ageing approach represents a better anti-ageing target than the "whole body" or "cellular ageing" concepts. The arterial system is the most suitable target, as it interconnects all the organs in the body, thus influencing them all. Second, we propose that an anti-ageing approach could be more successful in early than late ageing stages; middle-aged people seem to be the most appropriate candidates. Third, we believe that instead of searching for new medication, we should rely on already established medications with beneficial effects on the arterial wall. Renin-angiotensin system inhibitors and statins fulfill these criteria and are potential cornerstones of the new approach. The fourth hypothesis is based on the concept that in the early stages of arterial ageing only slight injury is present and therefore subtherapeutic, low-dose treatment would be effective. Fifth, we hypothesize that slight initial age-related arterial wall changes are reversible and could be corrected by a short-term (one month) treatment. Sixth, we hypothesize that the effects would be present for a certain period of time even after treatment termination. The listed assumptions combined represent the basis for a new, original anti-ageing approach - a subtherapeutic low-dose combination of a renin-angiotensin system inhibitor and a statin for one month (followed by approximately 6-12 months without treatment) could delay or even reverse the arterial ageing process and consequently decrease the incidence of cardiovascular disorders.