Relationship between carotid intima-media thickness and carotid artery stiffness assessed by ultrafast ultrasound imaging in patients with type 2 diabetes

Predicting cardiovascular risk stratification in apparently healthy population by using noninvasive ultrafast ultrasound imaging

BACKGROUND

To investigate the association between cardiovascular risk estimated using the Framingham Risk Score (FRS) and carotid stiffening determined using ultrafast pulse wave velocity (ufPWV) measurements in apparently healthy individuals.

METHODS

We enrolled 1034 apparently healthy participants without known cardiovascular disease who underwent ufPWV measurements. Clinical and laboratory findings, carotid intima-media thickness (cIMT), pulse wave velocity at the beginning of systole (PWV-BS), and pulse wave velocity at the end of systole (PWV-ES) were assessed. In FRS assessments based on major cardiovascular risk factors (CVRFs), participants were assigned into three risk categories: low risk (<10%, n = 679), intermediate risk (10-20%, n = 191), and high risk (>20%, n = 164); the low-risk category was further subdivided into three subcategories: < 1% (n = 58), 1%- 5% (n = 374) and > 5% (n = 247). Multivariate logistic regression analyses with crude and adjusted odds ratios (ORs) were used to evaluate the association of carotid stiffening and FRS-based risk stratification.

RESULTS

Carotid stiffening indicated by PWV-BS and PWV-ES differed notably between the FRS-estimated low-risk vs. intermediate-risk and high-risk categories, but only PWV-ES differed notably among the low-risk subcategories (all p < 0.010), and correlated notably with the FRS-estimated risk most obviously in low-risk participants (r = 0.517). In participants with cIMT < 0.050 cm, only PWV-ES differed significantly among the FRS-estimated risk categories (all p < 0.001). Increased PWV-BS (adjusted OR: 1.49; p = 0.003) and PWV-ES (adjusted OR: 1.29; p = 0.007) were both associated with FRS categories independent of conventional CVRFs in low- vs. intermediate-risk categories, but not in low- vs. high-risk categories (all p > 0.050).

CONCLUSION

In vivo imaging of carotid stiffening by ufPWV measurements is independently linked to FRS categories, and ufPWV indices may help stratify differing levels of cardiovascular risk in apparently healthy young people.

AVAILABILITY OF DATA AND MATERIAL

Data generated or analyzed during the study are available from the corresponding author by reasonable request.

Abnormal vascular thickness and stiffness in young adults with type 1 diabetes: new insights from cutting-edge ultrasound modalities

BACKGROUND

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality in patients with Type 1 Diabetes (T1D). Early markers of CVD include increased carotid intima-media thickness (CIMT) and pulse wave velocity (PWV), but these existing ultrasound technologies show limited spatial and temporal resolution in young adults. The purpose of this study is to evaluate the utility of high-resolution ultrasound modalities, including high frequency ultrasound CIMT (hfCIMT) and ultrafast ultrasound PWV (ufPWV), in young adults with Type 1 Diabetes.

METHODS

This is a prospective single-center observational cohort study including 39 participants with T1D and 25 age and sex matched controls. All participants underwent hfCIMT and ufPWV measurements. hfCIMT and ufPWV measures of T1D were compared with controls and associations with age, sex, BMI, A1c, blood pressure, and lipids were studied.

RESULTS

Mean age was 24.1 years old in both groups. T1D had a greater body mass index (27.7 [5.7] vs 23.1 [3.2] kg/m2), LDL Cholesterol, and estimated GFR, and had a mean A1c of 7.4 [1.0] % (57 mmol/mol) and diabetes duration of 16.1 [3.7] years with 56% using insulin pumps. In T1D, hfCIMT was significantly increased as compared to controls (0.435 ± 0.06 mm vs 0.379 ± 0.06 mm respectively, p < 0.01). ufPWV measures were significantly increased in T1D (systolic foot PWV: 5.29 ± 0.23 m/s vs 5.50 ± 0.37 m/s, p < 0.01; dicrotic notch PWV = 7.54 ± 0.46 m/s vs 7.92 ± 0.41 m/s, p < 0.01). Further, there was an impact of A1c-measured glycemia on hfCIMT, but this relationship was not seen with ufPWV. No significant statistical correlations between hfCIMT and ufPWV measures in either T1D or healthy controls were observed.

CONCLUSION

Young adults with T1D present with differences in arterial thickness and stiffness when compared with controls. Use of novel high-resolution ultrasound measures describe important relationships between early structural and vascular pathophysiologic changes and are promising tools to evaluate pre-clinical CVD risk in youth with T1D.

TRIAL REGISTRATION

ISRCTN91419926.

Local arterial stiffness measured by ultrafast ultrasound imaging in childhood cancer survivors treated with anthracyclines

Background

There is conflicting literature regarding the long-term effect of anthracycline treatment on arterial stiffness. This study assessed local arterial stiffness using ultrafast ultrasound imaging (UUI) in anthracycline treated childhood cancer survivors, at rest and during exercise.

Methods

20 childhood cancer survivors (mean age 21.02 ± 9.45 years) treated with anthracyclines (mean cumulative dose 200.7 ± 126.80 mg/m²) and 21 healthy controls (mean age 26.00 ± 8.91 years) were included. Participants completed a demographic survey, fasting bloodwork for cardiovascular biomarkers, and performed a submaximal exercise test on a semi-supine bicycle. Pulse wave velocity (PWV) was measured in the left common carotid artery by direct pulse wave imaging using UUI at rest and submaximal exercise. Both PWV at the systolic foot (PWV-SF) and dicrotic notch (PWV-DN) were measured. Central (carotid-femoral) PWV was obtained by applanation tonometry. Carotid measurements were taken by conventional ultrasound. Measures were compared using two-tailed Students t-test or Chi-squared test, as appropriate.

Results

There was no statistically significant difference (p > 0.05) between childhood cancer survivors and healthy controls in demographic parameters (age, sex, weight, height, BMI), blood biomarkers (total cholesterol, triglycerides, LDL-c, HDL-c, hs-CRP, fasting glucose, insulin, Hb A1c), cardiovascular parameters (intima media thickness, systolic and diastolic blood pressure, heart rate, carotid diameters, distensibility) or PWV measured by UUI at rest or at exercise. There was also no difference in the cardiovascular adaptation between rest and exercise in the two groups (p > 0.05). Multivariate analysis revealed age (p = 0.024) and LDL-c (p = 0.019) to be significant correlates of PWV-SF in childhood cancer survivors, in line with previously published data.

Conclusion

We did not identify a significant impact of anthracycline treatment in young survivors of childhood cancer on local arterial stiffness in the left common carotid artery as measured by UUI.

Individualized References of Carotid Stiffening Quantified With Ultrafast Ultrasound Imaging: Model Construction and Preliminary Validation

To establish and preliminarily validate an individualized reference of carotid stiffness quantified by ultrafast pulse wave velocity (ufPWV), our study included 225 healthy individuals in the modeling cohort and 628 individuals in the validation cohort. All participants underwent assessment of carotid intima-media thickness (cIMT), pulse wave velocity-beginning of systole and pulse wave velocity-end of systole (PWV-ES). A threshold equation of estimated PWV-ES was obtained by multiple linear regression analysis in the modeling cohort as follows: estimated PWV-ES (m/s) = 0.080 × age (y) + 0.767 × low-density lipoprotein (mmol/L) + 0.040 × systolic blood pressure (mm Hg) + 0.372 × sex (male = 1, female = 0) - 2.803. With this equation, the validation cohort was divided into the low PWV-ES (actual PWV-ES ≤ estimated PWV-ES) and high PWV-ES (actual PWV-ES > estimated PWV-ES) groups. A clear boundary was found to be present between the low PWV-ES and high PWV-ES groups in the validation cohort. Participants with increasing PWV-ES increased with age gradually. We further subdivided participants into cIMT subgroups using a cutoff thickness of 0.050 cm. Diagnostic performance analysis revealed that the sensitivity and specificity of the threshold equation were 78.9% and 73.9%, respectively. We established and validated a novel individualized reference equation for estimated PWV-ES, which can likely expand the application of prospective ufPWV assessment.

Clinical significance and influencing factors of carotid pulse wave velocity in patients with diabetic microangiopathy

PURPOSE

To evaluate the utility of carotid ultrafast pulse wave velocity (PWV) and explore its influencing factors in patients with type 2 diabetes mellitus (T2DM) microangiopathy.

METHODS

Seventy-seven patients with T2DM were divided into two groups according to the absence (Group A, n = 45) or presence (Group B, n = 32) of microangiopathy. The control group comprised 1544 healthy volunteers. Two-dimensional ultrasonography was used to measure intima-media thickness (IMT) of the carotid arteries, and ultrafast ultrasound imaging was used to measure PWV of the carotid arteries at the beginning of systole (PWV-BS) and the end of systole (PWV-ES).

RESULTS

The IMT, PWV-BS, and PWV-ES were higher in the T2DM group than in the control group, and the values in T2DM Group B were higher than those in Group A. IMT was positively correlated with PWV-BS and PWV-ES. Age and uric acid were influencing factors of PWV-ES, while age, uric acid, body mass index, glycated hemoglobin, and urine albumin/creatinine ratio were influencing factors of PWV-BS. PWV-ES was a more sensitive predictor than PWV-BS, and a PWV-ES critical value predicted carotid elasticity in patients with T2DM microangiopathy.

CONCLUSION

Ultrafast PWV can reflect early atherosclerosis and provide a noninvasive assessment of microangiopathy in patients with T2DM.

Carotid stiffening predicts cardiovascular risk stratification in mid-life: non-invasive quantification with ultrafast ultrasound imaging

PURPOSE

The present study investigated the association between Systematic COronary Risk Evaluation (SCORE)-estimated cardiovascular risk and carotid stiffening in a middle-aged population using ultrafast pulse wave velocity (ufPWV).

METHODS

This study enrolled 683 participants without known cardiovascular disease or diabetes mellitus who underwent ufPWV measurements. Clinical interviews, physical examinations, laboratory findings, carotid intima-media thickness (cIMT), pulse wave velocity (PWV) at the beginning of systole (PWV-BS), and PWV at the end of systole (PWV-ES) were assessed. Each participant underwent an assessment of SCORE risk based on major cardiovascular risk factors (CVRFs), including age, sex, smoking, systolic blood pressure (SBP), and total cholesterol (TC). Crude and adjusted odds ratios (ORs) with 95% confidence intervals and ordinal logistic regression were used. Overall CVRFs were adjusted to assess ORs.

RESULTS

cIMT and carotid stiffening in PWV-BS and PWV-ES were significantly different between sex subgroups (all P<0.05), but only PWV-ES increased gradually in age and SCORE-estimated risk subgroups (all P<0.05). Compared with cIMT (r=0.388, P<0.001) and PWV-BS (r=0.159, P<0.001), PWV-ES was more strongly correlated with SCORE categories (r=0.405, P<0.001). Higher PWV-ES values were associated with SCORE categories independently of sex, SBP, TC, and smoking in moderate-risk and high-risk subgroups (OR, 1.63; P<0.001 and OR, 2.12; P=0.024, respectively), but were not independent of age in all risk subgroups (all P>0.05).

CONCLUSION

Carotid stiffening quantified by ufPWV is linked to SCORE categories, and elevated PWV-ES may aid in cardiovascular risk stratification.

Angioplasty Induced Changes in Dialysis Vascular Access Compliance

Dialysis vascular access remains vitally important to maintain life and functional capacity with end stage renal disease. Angioplasty is an integral part of maintaining dialysis access function and patency. To understand the effect of angioplasty balloon dilation on vascular wall mechanics, we conducted a clinical study to evaluate the elastic modulus of the anastomosis in five subjects with anastomosis stenoses, before and after six angioplasty procedures, using B-mode ultrasound DICOM data. A novel and open source vascular ultrasound high-resolution speckle tracking software tool was used. The median lumen diameter increased from 3.4 to 5.5 mm after angioplasty. Meanwhile, the median elastic modulus of the 18 measurements at the anastomosis increased by 52.2%, from 2.24 × 10³ to 3.41 × 10³ mmHg. The results support our hypothesis that the structural changes induced in the vessel wall by balloon dilation lead to reduced vascular compliance and a higher elastic modulus of the vessel wall.

Noninvasive Measurement of Time-Varying Arterial Wall Elastance Using a Single-Frequency Vibration Approach

The arterial wall elastance is an important indicator of arterial stiffness and a kind of manifestation associated with vessel-related disease. The time-varying arterial wall elastances can be measured using a multiple-frequency vibration approach according to the Voigt and Maxwell model. However, such a method needs extensive calculation time and its operating steps are very complex. Thus, the aim of this study is to propose a simple and easy method for assessing the time-varying arterial wall elastances with the single-frequency vibration approach. This method was developed according to the simplified Voigt and Maxwell model. Thus, the arterial wall elastance measured using this method was compared with the elastance measured using the multiple-frequency vibration approach. In the single-frequency vibration approach, a moving probe of a vibrator was induced with a radial displacement of 0.15 mm and a 40 Hz frequency. The tip of the probe directly contacted the wall of a superficial radial artery, resulting in the arterial wall moving 0.15 mm radially. A force sensor attached to the probe was used to detect the reactive force exerted by the radial arterial wall. According to Voigt and Maxwell model, the wall elastance (E_single) was calculated from the ratio of the measured reactive force to the peak deflection of the displacement. The wall elastances (E_multiple) measured by the multiple-frequency vibration approach were used as the reference to validate the performance of the single-frequency approach. Twenty-eight healthy subjects were recruited in the study. Individual wall elastances of the radial artery were determined with the multiple-frequency and the single-frequency approaches at room temperature (25 °C), after 5 min of cold stress (4 °C), and after 5 min of hot stress (42 °C). We found that the time-varying E_single curves were very close to the time-varying E_multiple curves. Meanwhile, there was a regression line (E_single = 0.019 + 0.91 E_multiple, standard error of the estimate (SEE) = 0.0295, p < 0.0001) with a high correlation coefficient (0.995) between E_single and E_multiple. Furthermore, from the Bland-Altman plot, good precision and agreement between the two approaches were demonstrated. In summary, the proposed approach with a single-frequency vibrator and a force sensor showed its feasibility for measuring time-varying wall elastances.

Absent atherosclerotic risk factors are associated with carotid stiffening quantified with ultrafast ultrasound imaging

OBJECTIVES

To evaluate carotid stiffening in participants without conventional cardiovascular risk factors (CVRFs) by using ultrafast pulse wave velocity (ufPWV).

METHODS

The present study enrolled 517 participants without conventional CVRFs (CVRF-Free total population). Subjects in this population were defined as current non-smokers with untreated blood pressure < 140/90 mmHg, fasting blood glucose (FBG) < 7.0 mmol/L, total cholesterol (TC) < 6.2 mmol/L, low-density lipoprotein cholesterol < 4.1 mmol/L, and high-density lipoprotein cholesterol ≥ 1.0 mmol/L. Participants in the subgroup with optimal CVRFs (CVRF-Optimal subgroup; n = 188) were defined as having blood pressure < 120/80 mmHg, TC < 5.2 mmol/L, and FBG < 5.6 mmol/L. Clinical interviews, physical examinations, serum draw, carotid intima-media thickness (cIMT), and ufPWV were evaluated. Adjusted odds ratios (ORs) with 95% confidence intervals and ordinal logistic regression models were used.

RESULTS

Carotid stiffening was present in 46.2-54.5% of CVRF-Free subjects. Age, male sex, and body mass index (BMI) were independently associated with carotid stiffening in both the CVRF-Free total population and CVRF-Optimal subgroup (OR for age = 1.10-1.11, OR for male sex = 2.65-7.19, OR for BMI = 1.34-1.62; p < 0.05). Carotid stiffening was associated with TC only in the CVRF-Free total population (OR for TC = 1.84; p = 0.034).

CONCLUSIONS

Many CVRF-Free individuals have carotid stiffening. ufPWV for atherosclerotic stiffening aids the assessment of early atherogenesis and may further clarify the true status of healthy adults without CVRFs.

KEY POINTS

• CVRF-Optimal individuals have a lower carotid stiffness than CVRF-Free populations. • ufPWV is a quantitative predictor for the early assessment of AS. • Absent major CVRFs cannot be considered low risk for carotid stiffening and atherosclerosis.

Diabetes and carotid artery disease: a narrative review

Diabetes mellitus (DM) has been linked to an increased prevalence and severity of carotid artery disease, as well as polyvascular disease. Carotid disease is also associated with obesity and abnormal peri-organ and intra-organ fat (APIFat) deposition (i.e., excess fat accumulation in several organs such as the liver, heart and vessels). In turn, DM is associated with APIFat. The coexistence of these comorbidities confers a greater risk of vascular events. Clinicians should also consider that carotid bruits may predict cardiovascular risk. DM has been related to a greater risk of adverse outcomes after carotid endarterectomy or stenting. Whether modifying risk factors (e.g., glycaemia and dyslipidaemia) in DM patients can improve the outcomes of these procedures needs to be established. Furthermore, DM is a risk factor for contrast-induced acute kidney injury (CI-AKI). The latter should be recorded in DM patients undergoing carotid stenting since it can influence both short- and long-term outcomes. From a pathophysiological perspective, functional changes in the carotid artery may precede morphological ones. Furthermore, carotid plaque characteristics are increasingly being studied in terms of vascular risk stratification and monitoring short-term changes attributed to treatment. The present narrative review discusses the recent (2019) literature on the associations between DM and carotid artery disease. Physicians and vascular surgeons looking after patients with carotid disease and DM should consider these links that may influence outcomes. Further research in this field is also needed to optimise the treatment of such patients.

Establishing normal reference value of carotid ultrafast pulse wave velocity and evaluating changes on coronary slow flow

Pulse wave velocity (PWV) measured by ultrafast ultrasound imaging can early evaluate arteriosclerosis. The study aimed to establish normal reference range for ufPWV in healthy adults and explore its influencing factors, and evaluate the ufPWV changes on coronary slow flow (CSF). ufPWV at the beginning and end of systole (ufPWV-BS and ufPWV-ES, respectively) was measured in healthy adults (201 cases). CSF was diagnosed based on thrombolysis in myocardial infarction (TIMI) frame count during coronary angiography. ufPWV-BS and ufPWV-ES were compared between CSF (50 cases) and control groups (50 healthy age-, body mass index-, and blood pressure-matched adults). In healthy adults, average ufPWV-BS and ufPWV-ES was 5.36 ± 1.27 m/s and 6.99 ± 1.93 m/s, respectively. ufPWV-BS and ufPWV-ES positively correlated with age, body mass index, and blood pressure. ufPWV-BS and ufPWV-ES in the CSF group were higher than in the control group (ufPWV-BS, 6.05 ± 1.07 vs. 5.26 ± 0.89 m/s, P < 0.001; ufPWV-ES, 9.07 ± 1.84 vs. 6.84 ± 1.08 m/s, P < 0.001). Receiver operating characteristic curves showed that ufPWV-ES was more sensitive than ufPWV-BS. The normal reference range of ufPWV for healthy adults was established. Age, body mass index, and blood pressure were the main influencing factors. ufPWV was increased in the patients with CSF. The findings indicated that, in addition to reflecting atherosclerosis, ufPWV might also provide a basis for the noninvasive evaluation of microvascular impairment in the patients with CSF.