High Brachial Ankle Pulse Wave Velocity as a Marker for Predicting Coronary Artery Stenosis in Patients with Type 2 Diabetes

Polyvinyl Alcohol Phantoms With Heterogeneous Plaques: Estimation of Pulse Wave Velocity at the Stenotic Region Using Pulse Wave Imaging

OBJECTIVE

Plaque characterization is essential for stroke prevention. In the study reported herein, we describe a heterogeneous phantom manufacturing technique with varying plaque compositions of different stiffness using polyvinyl alcohol (PVA) to emulate stenotic arteries and evaluated the use of pulse wave imaging (PWI) to assess plaque stiffness by comparing derived pulse wave velocities, with the goal of assessing plaque vulnerability and identifying high-risk patients for stroke.

METHODS

Five stenotic phantoms (50% stenosis) were fabricated by pouring PVA solutions into 3-D-printed molds. Two of the phantoms had heterogeneous plaque compositions of soft (E0 = 13 kPa) and intermediate (E0 = 40 kPa) materials and of stiff (E0 = 54 kPa) and intermediate materials. Ultrasound sequences were acquired as the arterial phantoms were connected to a pulsating pump, and PWI was performed on the ultrasound acquisition using normalized cross-correlation to track the pulse-induced phantom wall distension propagations. Pulse wave velocities were estimated by fitting a linear regression line between the arrival time of the peak acceleration of the wall distension waveform and the corresponding location.

RESULTS

Arterial phantoms with heterogeneous plaque stiffness were successfully fabricated. Pulse wave velocities of 2.06, 2.21, 2.49, 2.67 and 3.31 m/s were found in the phantom experiments using PWI for homogeneous soft plaque, the heterogeneous soft and intermediate plaque, homogeneous intermediate plaque, the heterogeneous stiff and intermediate plaque and homogeneous stiff plaque, respectively.

CONCLUSION

A novel arterial phantom building technique was reported with varying heterogenous plaque compositions of different stiffness. The feasibility of using PWI to evaluate plaque stiffness in stenotic arteries was determined and found that PWI can distinguish between plaques of distinct stiffness and composition.

Pepsinogen ratio and brachial-ankle pulse wave velocity: a cross-sectional study on their interrelationship in atherosclerosis

BACKGROUND

Existing research has established the pepsinogen ratio (PGR) as a complex biomarker, not only as an independent predictor for various gastrointestinal diseases but also in its association with atherosclerotic cardiovascular diseases. However, the precise mechanism linking changes in PGR to cardiovascular pathologies remains unclear. The objective of this study is to quantitatively elucidate the association between PGR and brachial-ankle pulse wave velocity (baPWV) as an indicator of atherosclerotic progression.

METHODS

We conducted a cross-sectional study that analyzed clinical data from 465 patients who underwent health screenings. One-way Analysis of Variance (ANOVA) identified potential risk factors affecting baPWV. Multiple logistic regression was employed to evaluate if PGR serves as an independent risk factor for elevated baPWV after accounting for these variables. Generalized additive models and smoothed curve fitting were utilized to investigate the possibility of a nonlinear association between PGR and baPWV. When such nonlinearity was found, threshold effect analysis pinpointed the inflection point in this relationship, followed by segmented correlation analyses.

RESULTS

PGR negatively correlated with both right baPWV (RbaPWV) and left baPWV (LbaPWV) after adjusting for confounders. Smoothed curve analyses revealed nonlinear relationships, with inflection points at 22.5 for RbaPWV and 22.3 for LbaPWV. For PGR values below 22.5, a significant negative correlation with RbaPWV was observed (β = - 6.3 cm/s, P < 0.001). Conversely, for PGR values above 22.5, no significant linear relationship was found (P = 0.141). Similarly, when PGR was below 22.3, a strong negative correlation with LbaPWV was detected (β = - 7.0 cm/s, P < 0.001), but such correlation was absent for higher PGR levels (P = 0.273).

CONCLUSION

The study reveals that PGR is associated with RbaPWV and LbaPWV in a nonlinear manner. Specifically, lower levels of PGR were linearly and inversely correlated with baPWV, but this relationship became nonlinear at higher PGR levels. These findings suggest that modulating PGR levels may offer a therapeutic strategy for managing atherosclerosis.

Computational clustering reveals differentiated coronary artery calcium progression at prevalent levels of pulse wave velocity by classifying high-risk patients

Many studies found that increased arterial stiffness is significantly associated with the presence and progression of Coronary Calcium Score (CCS). However, none so far have used machine learning algorithms to improve their value. Therefore, this study aims to evaluate the association between carotid-femoral Pulse Wave Velocity (cfPWV) and CCS score through computational clustering. We conducted a retrospective cross-sectional study using data from a cardiovascular risk screening program that included 377 participants. We used an unsupervised clustering algorithm using age, weight, height, blood pressure, heart rate, and cfPWV as input variables. Differences between cluster groups were analyzed through Chi-square and T-student tests. The association between (i) cfPWV and age groups, (ii) log (CCS) and age groups, and (iii) cfPWV and log(CCS) were addressed through linear regression analysis. Clusters were labeled post hoc based on cardiovascular risk. A "higher-risk group" had significantly higher left (0.76 vs. 0.70 mm, P < 0.001) and right (0.71 vs. 0.66 mm, P = 0.003) intima-media thickness, CCS (42 vs. 4 Agatston units, P = 0.012), and ascending (3.40 vs. 3.20 cm, P < 0.001) and descending (2.60 vs. 2.37 cm, P < 0.001) aorta diameters. Association with age appeared linear for cfPWV and exponential for log (CCS). The progression of the log (CCS) and cfPWV through age groups was steeper in the "higher-risk group" than in the "lower-risk group". cfPWV strongly correlated with CCS, and CCS progression over cfPWV differed among clusters. This finding could improve PWV as a "gate-keeper" of CCS testing and potentially enhance cardiovascular risk stratification.

Pulse wave imaging of a stenotic artery model with plaque constituents of different stiffnesses: Experimental demonstration in phantoms and fluid-structure interaction simulation

Vulnerable plaques associated with softer components may rupture, releasing thrombotic emboli to smaller vessels in the brain, thus causing an ischemic stroke. Pulse Wave Imaging (PWI) is an ultrasound-based method that allows for pulse wave visualization while the regional pulse wave velocity (PWV) is mapped along the arterial wall to infer the underlying wall compliance. One potential application of PWI is the non-invasive estimation of plaque's mechanical properties for investigating its vulnerability. In this study, the accuracy of PWV estimation in stenotic vessels was investigated by computational simulation and PWI in validation phantoms to evaluate this modality for assessing future stroke risk. Polyvinyl alcohol (PVA) phantoms with plaque constituents of different stiffnesses were designed and constructed to emulate stenotic arteries in the experiment, and the novel fabrication process was described. Finite-element fluid-structure interaction simulations were performed in a stenotic phantom model that matched the geometry and parameters of the experiment in phantoms. The peak distension acceleration of the phantom wall was tracked to estimate PWV. PWVs of 2.57 ms-1, 3.41 ms-1, and 4.48 ms-1 were respectively obtained in the soft, intermediate, and stiff plaque material in phantoms during the experiment using PWI. PWVs of 2.10 ms-1, 3.33 ms-1, and 4.02 ms-1 were respectively found in the soft, intermediate, and stiff plaque material in the computational simulation. These results demonstrate that PWI can effectively distinguish the mechanical properties of plaque in phantoms as compared to computational simulation.

Arterial Stiffness as a Predictor of the Index of Atherosclerotic Cardiovascular Disease in Hypertensive Patients

OBJECTIVE

The aim of this study was to evaluate the predictive value of carotid-femoral pulse wave velocity (cfPWV) and cardiovascular disease in the hypertensive population in China and to determine the specific cfPWV cut-off value for assessing future cardiovascular disease (CVD) risk.

METHODS

This cross-sectional study included 630 hospital patients with primary hypertension and multiple cardiovascular risk factors or complications involving damage to clinical target organs. The study was conducted between July 2007 and October 2008. Atherosclerotic cardiovascular disease (ASCVD) risk calculations were computed according to criteria presented by the American College of Cardiology and the American Heart Association. Patients were stratified by a predefined risk threshold of 10% and divided into two groups: ASCVD ≥ 10% or ASCVD < 10%. cfPWV was used as a marker of arterial stiffness. A receiver operating characteristics (ROC) curve was applied to establish the optimal cfPWV cut-off point to differentiate between participants with and without ASCVD risk.

RESULTS

In the study cohort of 630 patients (age 63.55.2 ± 8.6 years, 61.7% male) with primary hypertension, the pressure indices (augmented pressure, augmentation index [AIx], aortic pulse pressure, aortic systolic pressure [SBP]) and Framingham Risk Scores (FRS) were greater in females than in males (p < 0.001); ASCVD risk scores and peripheral diastolic pressure (DBP) were higher in males (p < 0.05). All hemodynamic indices showed a significant positive correlation with ASCVD risk scores and FRS; AIx was not correlated with ASCVD risk scores. In multivariate logistic analysis, cfPWV was significantly associated with ASCVD risk (OR: 1.324, 95% confidence interval: 1.119-1.565, p < 0.001) after adjusting for age, gender, smoking, body mass index, total cholesterol, fasting blood glucose, antihypertensive treatment, statin treatment, and DBP. In the ROC analysis, the area under the curve was 0.758 and 0.672 for cfPWV and aortic SBP (p < 0.001 and p < 0.001, respectively); the optimal critical value of cfPWV and aortic SBP was 12.45 m/s (sensitivity 63.2%, specificity 77.8%) and 124.5 mmHg (sensitivity 63.9%, specificity 65.3%).

CONCLUSIONS

cfPWV is significantly correlated with the risk of ASCVD. The best cut-off value of cfPWV for assessing future CVD risk in the hypertensive population in China is 12.45 m/s.

Brachial-ankle pulse wave velocity as a predictor of long-term cardiovascular events in 2174 subjects with type 2 diabetes mellitus: A retrospective cohort study

The prognostic value of arterial stiffness in patients with diabetes mellitus (DM) remains unclear. The aim of this study was to investigate the association between brachial-ankle pulse wave velocity (baPWV) and the occurrence of cardiovascular events in people with DM. A total of 2714 subjects (mean age, 63.6 years; males, 59.3%) with type 2 DM and without documented cardiovascular disease and stroke were analyzed. The primary end-point of this study was composite cardiovascular events of cardiac death, non-fatal myocardial infarction, coronary revascularization and stroke. There were 118 composite events (4.3%) during a median follow-up period of 3.84 years (interquartile range, 1.60-5.52 years). In multivariable Cox regression analysis, higher baPWV (≥1672 cm/s) was associated with composite events even after controlling for potential confounders (hazard ratio [HR], 2.00; 95% confidence interval [CI], 1.31-3.07; P = .001). Compared to the lowest baPWV tertile, both middle (HR, 1.84; 95% CI, 1.03-3.27; P = .037) and the highest (HR, 2.97; 95% CI, 1.69-5.22; P < .001) tertile of baPWV were associated with increased risk of cardiovascular events in the same multivariable model. In conclusion, the baPWV was associated with cardiovascular events in people with type 2 DM. Considering the simplicity and convenience of baPWV measurement, baPWV may be useful for risk stratification of people with type 2 DM.

Risk assessment indicators and brachial-ankle pulse wave velocity to predict atherosclerotic cardiovascular disease

Brachial-ankle pulse wave velocity (baPWV) is used for predicting the severity of vascular damage and prognosis of atherosclerotic cardiovascular disease (ASCVD) in people with hypertension and diabetes mellitus. This correlation study aimed to compare the baPWV with other risk indicators for identification of subclinical vascular disease for primary prevention and to determine the clinical utility of baPWV-guided therapy in improving prognosis in high-risk subjects. We included 4881 subjects who underwent voluntary health examination at Mackay Memorial Hospital, Taiwan between 2014 and 2019. Participants were categorized into the low-risk (<5%), borderline-risk (5%-7.4%), intermediate-risk (7.5%-19.9%), and high-risk (≥20%) groups based on the 10-year risk for ASCVD. The predictive risk criteria, that is, the metabolic syndrome score, Framingham Risk Score, estimated glomerular filtration rate, and baPWV were compared among these groups. The chief cause of induced responses and the relationships between parameters were identified using principal component analysis. The participants' ages, body mass index, systolic, diastolic blood pressure, triglycerides, fasting glucose, hemoglobin A1c, creatinine, neutrophil-to-lymphocyte ratio, monocyte-to-lymphocyte ratio, metabolic syndrome, Framingham Risk Score, and age-related arterial stiffness (vascular age) increased significantly from the low-risk to high-risk groups (P < .001). The mean estimated glomerular filtration rate decreased significantly from the low- to high-risk groups (P < .001). The predicted vascular age and actual age differed significantly between the intermediate- and high-risk groups (P < .001). High-density lipoprotein levels plummeted significantly among the 4 groups (P < .001). The right and left baPWV and ankle brachial index differed significantly among the 4 groups (all P < .001) and increased from the low-risk to high-risk groups (P < .001). Carotid Doppler ultrasonography revealed a significant increase in plaque formation (23.5%, 35.4%, 46.3%, and 61.5% for the low-, borderline-, intermediate, and high-risk groups, respectively). The total explanatory variation was 61.9% for 2 principal variation factors (baPWV, 36.8% and creatinine, 25.1%). The vascular age predicted using baPWV greatly exceeded the chronological age. Plaque formation was significant even in the low-risk group, and its frequency increased with the predicted ASCVD risk. Risk indicators and baPWV are useful predictors of ASCVD, which in conjunction with conventional pharmacotherapy could be useful for primary prevention of plaque formation in subjects with cardiovascular comorbidities.

The Plasma Atherogenic Index is an Independent Predictor of Arterial Stiffness in Healthy Koreans

The plasma atherogenic index (AIP) has been suggested as a useful independent predictor of cardiovascular diseases (CVDs) in high CV risk patients. We investigated the association between AIP and arterial stiffness measured by brachial-ankle pulse wave velocity (baPWV) in healthy adults. A total of 3468 healthy subjects without any metabolic or CV diseases were enrolled. Anthropometric and CV risk factors were measured. The AIP was defined as the base 10 logarithm of the ratio of the concentration of triglycerides to high-density lipoprotein-cholesterol. Subjects were classified into AIP quartiles. There were gradual deteriorations in metabolic parameters and increase in baPWV across the increasing AIP quartiles. In a fully adjusted analysis, compared with Q1 (lowest quartile) group, the odds ratio (95% confidence interval) for increased baPWV was higher in Q2 1.51, Q3 1.64, and Q4 (highest quartile) 2.77 among men, and Q2 1.09, Q3 1.55, and Q4 1.83 among women (all P trend  <0 .05). There was a strong association between AIP and baPWV, and a higher AIP was an independent predictor of increased arterial stiffness in healthy Korean men and women. The AIP may be a simple screening tool for subclinical atherosclerosis.

Ultrasound Methods in the Evaluation of Atherosclerosis: From Pathophysiology to Clinic

Atherosclerosis is a key pathological process that causes a plethora of pathologies, including coronary artery disease, peripheral artery disease, and ischemic stroke. The silent progression of the atherosclerotic disease prompts for new surveillance tools that can visualize, characterize, and provide a risk evaluation of the atherosclerotic plaque. Conventional ultrasound methods—bright (B)-mode US plus Doppler mode—provide a rapid, cost-efficient way to visualize an established plaque and give a rapid risk stratification of the patient through the Gray–Weale standardization—echolucent plaques with ≥50% stenosis have a significantly greater risk of ipsilateral stroke. Although rather disputed, the measurement of carotid intima-media thickness (C-IMT) may prove useful in identifying subclinical atherosclerosis. In addition, contrast-enhanced ultrasonography (CEUS) allows for a better image resolution and the visualization and quantification of plaque neovascularization, which has been correlated with future cardiovascular events. Newly emerging elastography techniques such as strain elastography and shear-wave elastography add a new dimension to this evaluation—the biomechanics of the arterial wall, which is altered in atherosclerosis. The invasive counterpart, intravascular ultrasound (IVUS), enables an individualized assessment of the anti-atherosclerotic therapies, as well as a direct risk assessment of these lesions through virtual histology IVUS.

A model to predict risk of stroke in middle-aged adults with type 2 diabetes generated from a nationwide population-based cohort study in Korea

AIMS

The incidence of stroke differs between Asians and Caucasians, and between people with or without diabetes mellitus (DM). This study aimed to develop a model to predict the risk of stroke in middle-aged patients with type 2 DM.

METHODS

Using the National Health Insurance Database in Korea, data from patients aged 40-64 years with type 2 DM who received a health examination from 2009 to 2012 (n = 1,297,131) were analyzed as development (n = 907,992) and validation (n = 389,139) cohorts. Cox proportional-hazards regression model was used to derive a risk-scoring system, and 13 predictive variables were selected. A risk score nomogram based on the risk prediction model was created to estimate the 5-year risk of stroke.

RESULTS

In patients with type 2 DM, significant predictors for the development of stroke were older age, being male or a current smoker, lack of exercise, low body mass index, low estimated glomerular filtration rate, presence of coronary heart disease, longer duration of DM, insulin or multiple oral hypoglycemic agents use, low (<100 mg/dL) or high (≥140 mg/dL) fasting blood glucose, high systolic blood pressure, high total cholesterol, and presence of atrial fibrillation. The concordance indexes for stroke prediction were 0.703 (95% confidence interval [CI] 0.700-0.707) in the development cohort and 0.703 (95% CI 0.698-0.708) in the validation cohort.

CONCLUSIONS

We developed a risk model using various clinical parameters to predict stroke in patients with type 2 DM. This model may provide helpful information for identifying high-risk patients and guide prevention of stroke in this specific population.

Association of impaired arterial wall properties with the presence of coronary artery disease in patients with abdominal aortic aneurysms

Pulse wave velocity (PWV) is a valid, clinically feasible marker of arterial stiffening, and a strong predictor of outcomes. The present study aimed to compare aortic elastic properties in patients with abdominal aortic aneurysms (AAA), with or without coronary artery disease (CAD), as well as healthy individuals. A total of 130 patients with AAA, eligible for interventional repair, and 30 healthy individuals, comprising the control group (HC), were enrolled. Presence of CAD was identified by coronary angiography. Aortic PWV (aPWV) was measured using the Arteriograph. aPWV was found considerably higher in AAA patients compared with HC group (11.5 ± 2.9 vs 7.3 ± 1.6 m/s, P < .001). Importantly, among patients with AAA, those with concomitant CAD (n = 41) had greater aPWV than those without CAD (12.5 ± 2.9 vs 11.0 ± 3.0 m/s, P = .03). In receiver operator curve (ROC) analysis, a value of aPWV above 12.8 m/s was identified to correlate with the presence of CAD in the AAA patient population. After adjustment for confounders, including hypertension which is one of the major risk factors for abdominal aneurysms, multivariate logistic regression analysis revealed that this aPWV cutoff remained independently associated with presence of CAD [odds ratio = 1.64, 95% confidence interval =1.19-4.08, P = .03]. The coexistence of CAD and AAA is characterized by a greater arterial stiffness. This finding should be taken into consideration when selecting endovascular stents with more favorable elastic properties. Moreover, AAA patients with high aPWV (>12.8 m/s) are more likely to also have CAD, and this may be considered by vascular surgeons when evaluating patients' cardiovascular risk.

Association of serum FAM19A5 with metabolic and vascular risk factors in human subjects with or without type 2 diabetes

OBJECTIVES

A recent experimental study revealed that family with sequence similarity 19 [chemokine (C-C motif)-like] member A5 (FAM19A5), a novel secreted adipokine, has inhibitory effects on vascular smooth muscle cell proliferation and migration, and on neointima formation in injured arteries. We investigated the associations between serum FAM19A5 concentration and cardio-metabolic risk factors for the first time in human subjects.

METHODS

Circulating FAM19A5 concentrations and their associations with cardio-metabolic risk factors were explored in 223 individuals (45 without diabetes and 178 with type 2 diabetes).

RESULTS

Serum FAM19A5 concentrations (pg/mL) were greater in patients with type 2 diabetes [median (interquartile range), 172.70 (116.19, 286.42)] compared with non-diabetic subjects [92.09 (70.32, 147.24)] (p < 0.001). Increasing serum FAM19A5 tertile was associated with trends of increasing waist-to-hip ratio, fasting plasma glucose, glycated haemoglobin and mean brachial-ankle pulse wave velocity. Serum FAM19A5 was positively correlated with waist circumference, waist-to-hip ratio, alanine aminotransferase, fasting plasma glucose, glycated haemoglobin and mean brachial-ankle pulse wave velocity. Multiple stepwise regression analyses identified waist-to-hip ratio, low-density lipoprotein cholesterol and brachial-ankle pulse wave velocity as determining factors for log-transformed serum FAM19A5 concentration (R² = 0.0689).

CONCLUSION

A novel adipokine FAM19A5 was related to various metabolic and vascular risk factors in humans, suggesting its potential as a biomarker of cardio-metabolic disease.

Pulse Wave Velocity in Atherosclerosis

Early detection of subclinical atherosclerosis is important to reduce patients' cardiovascular risk. However, current diagnostic strategy focusing on traditional risk factors or using risk scoring is not satisfactory. Non-invasive imaging tools also have limitations such as cost, time, radiation hazard, renal toxicity, and requirement for specialized techniques or instruments. There is a close interaction between arterial stiffness and atherosclerosis. Increased luminal pressure and shear stress by arterial stiffening causes endothelial dysfunction, accelerates the formation of atheroma, and stimulates excessive collagen production and deposition in the arterial wall, leading to the progression of atherosclerosis. Pulse wave velocity (PWV), the most widely used measure of arterial stiffness, has emerged as a useful tool for the diagnosis and risk stratification of cardiovascular disease (CVD). The measurement of PWV is simple, non-invasive, and reproducible. There have been many clinical studies and meta-analyses showing the association between PWV and coronary/cerebral/carotid atherosclerosis. More importantly, longitudinal studies have shown that PWV is a significant risk factor for future CVD independent of well-known cardiovascular risk factors. The measurement of PWV may be a useful tool to select subjects at high risk of developing subclinical atherosclerosis or CVD especially in mass screening.

Pulse Wave Velocity in Atherosclerosis

Early detection of subclinical atherosclerosis is important to reduce patients' cardiovascular risk. However, current diagnostic strategy focusing on traditional risk factors or using risk scoring is not satisfactory. Non-invasive imaging tools also have limitations such as cost, time, radiation hazard, renal toxicity, and requirement for specialized techniques or instruments. There is a close interaction between arterial stiffness and atherosclerosis. Increased luminal pressure and shear stress by arterial stiffening causes endothelial dysfunction, accelerates the formation of atheroma, and stimulates excessive collagen production and deposition in the arterial wall, leading to the progression of atherosclerosis. Pulse wave velocity (PWV), the most widely used measure of arterial stiffness, has emerged as a useful tool for the diagnosis and risk stratification of cardiovascular disease (CVD). The measurement of PWV is simple, non-invasive, and reproducible. There have been many clinical studies and meta-analyses showing the association between PWV and coronary/cerebral/carotid atherosclerosis. More importantly, longitudinal studies have shown that PWV is a significant risk factor for future CVD independent of well-known cardiovascular risk factors. The measurement of PWV may be a useful tool to select subjects at high risk of developing subclinical atherosclerosis or CVD especially in mass screening.