Peripheral vascular stiffness, assessed with two-dimensional speckle tracking versus the degree of coronary artery calcification, evaluated by tomographic coronary artery calcification index

Relationship between tissue characteristics and mechanical properties of coronary plaques: a comparison between integrated backscatter intravascular ultrasound (IVUS) and speckle-tracking IVUS

High-risk coronary plaques have certain morphological characteristics. Thus, comprehensive assessment is needed for the risk stratification of plaques in patients with coronary artery disease. Integrated backscatter intravascular ultrasound (IB-IVUS) has been used successfully used to evaluate the tissue characteristics of coronary plaques; however, the mechanical properties of plaques have been rarely assessed. Therefore, we developed Speckle-tracking IVUS (ST-IVUS) to evaluate the mechanical properties of coronary plaque. This study aimed to evaluate the relation between the tissue characteristics of coronary plaques using IB-IVUS and their mechanical properties using ST-IVUS. We evaluated 95 non-targeted plaques in 95 patients undergoing elective percutaneous coronary intervention to the left anterior descending artery. We set regions of interest (ROIs) in the cross-sectional images of coronary plaques where we divided 120 degree plaques into four quadrants (every 30 degrees), with the center at the area of maximum atheroma thickness. We measured relative calcification area (%CA, relative fibrous area (%FI) and relative lipid pool area (%LP) in a total of 380 ROIs. In ST-IVUS analysis, we measured strain in the circumferential direction of the lumen area (LA strain: %), the external elastic membrane area strain (EEM strain: %), and strain in the radial direction (radial strain: %). On global cross-sectional area IB-IVUS analysis, the %CA was 1.2 ± 1.2%; the %FI was 49.0 ± 15.9%, and the %LP was 49.7 ± 16.5%. In ST-IVUS analysis, the LA strain was 0.67 ± 0.43%; the EEM strain was 0.49 ± 0.33%, and the radial strain was 2.02 ± 1.66%. On regional analysis, the %LP was not associated with the LA strain (r = - 0.002 p = 0.97), the EEM strain (r = - 0.05 p = 0.35), or with the radial strain (r = - 0.04 p = 0.45). These trends were seen between the %FI and the LA strain (r = 0.02 p = 0.74), the %FI and the EEM strain (r = 0.05 p = 0.35), and the %FI and the radial strain (r = 0.04 p = 0.50). A significant correlation was only observed between the %CA and the LA strain (r = - 0.15 p = 0.0038). Our findings indicate that the associations between mechanical properties and tissue characteristics lacked statistical significance, more often than not, and that it is necessary to evaluate the mechanical properties as well as plaque characteristics for risk stratification of coronary plaques.

Evaluation of common carotid artery in type 1 diabetes mellitus patients through speckle tracking carotid strain ultrasonography

PURPOSE

We aimed to evaluate the effectiveness of speckle tracking carotid strain (STCS) technique, which enables measurement of arterial stiffness and strain parameters, in the detection of early atherosclerotic findings in type 1 diabetes mellitus (T1DM).

METHODS

We prospectively enrolled 30 T1DM patients and 30 age- and sex-matched control participants with no history of cardiovascular disease. All study population underwent carotid ultrasonography. Radial and circumferential movement of the common carotid artery (CCA) in the transverse plane as the well as the radial movement of the CCA in the longitudinal plane were calculated automatically by using the STCS method. In addition, the strain (%), strain rate (per second), and peak circumferential and radial displacements (mm) were calculated. Arterial stiffness parameters, such as elastic modulus, distensibility, arterial compliance, and β-stiffness index, were calculated using the radial measurements. The mean value of the carotid intima media thickness (CIMT) was calculated semi-automatically for each CCA, in the longitudinal plane. We also analyzed the patients' overall body composition.

RESULTS

T1DM and control groups were compared in terms of strain and stiffness parameters and no statistically significant difference was found (p > 0.05). CIMT was higher in diabetic patients than in the control group (p = 0.039). In both groups, age was correlated with all arterial stiffness and strain parameters (p < 0.05). The duration of diabetes was also correlated with β-stiffness index, distensibility, and elastic modulus in the longitudinal plane (p < 0.05). In the diabetic group, abdominal fat ratio, whole body fat ratio, and fat mass were correlated with radial and circumferential displacement and strain parameters in transverse plane, and radial displacement in longitudinal plane (p < 0.05, for each). Diabetic patients were divided into subgroups according to the presence of nephropathy and dyslipidemia. Although no significant difference was found between the groups in terms of CIMT, patients with nephropathy had higher values for transverse and longitudinal elastic modulus, pulse-wave velocity, and longitudinal β-stiffness index, as well as lower values for longitudinal arterial compliance and distensibility, compared with patients without nephropathy (p < 0.05). Also, patients with dyslipidemia had higher longitudinal β-stiffness and elastic modulus values compared with patients without dyslipidemia (p < 0.05).

CONCLUSION

STCS ultrasonography is an effective, easy, and noninvasive method for evaluating the arterial elasticity. It may provide an early assessment of atherosclerosis in patients with T1DM, especially in the presence of nephropathy and dyslipidemia; thus, together with CIMT measurement, it may be used more frequently to detect subclinical damage and stratify atherosclerosis.

"Apple does not fall far from the tree" - subclinical atherosclerosis in children with familial hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia (FH) increases the risk of atherosclerosis in children and adults. Atherosclerotic cardiovascular disease in young patients FH is usually subclinical but recognition of children with more pronounced changes is crucial for adjusting effective management. Aim of this research was to use ultrasonography with two-dimensional speckle tracking (2DST) and tonometry to evaluate atherosclerotic changes in patients with FH (parents and their offspring).

METHODS

Applanation tonometry and carotid arteries sonography with evaluation of the intima-media complex thickness (IMCT) and application of the 2DST were performed in 20 families with FH (20 parents and 29 children). The same size control group (age and sex matched) was included. Results were compared between peers and between generations together with the correlation analysis.

RESULTS

Adults with FH, in comparison with healthy peers, presented significantly more atherosclerotic plaques (9 vs. 2, p = 0.0230), had significantly thicker IMC (0.84 ± 0.19 vs. 0.56 ± 0.06 mm, p < 0.0001) and had stiffer arterial wall (for stain: 6.25 ± 2.3 vs. 8.15 ± 2.46, p = 0.0103). In children from both groups there were no atherosclerotic plaques and IMCT did not differ significantly (0.42 ± 0.07 vs. 0.39 ± 0.04, p = 0.1722). However, children with FH had significantly stiffer arterial wall according to 2DST (for strain: 9.22 ± 3.4 vs. 11.93 ± 3.11, p = 0.0057) and tonometry (for the pulse wave velocity: 4.5 ± 0.64 vs.3.96 ± 0.62, p = 0.0047). These parameters correlated with atherosclerosis surrogates in their parents (p < 0.001) but were not significantly affected by presence of presumed pathogenic gene variant.

CONCLUSIONS

Children with FH presented subclinical atherosclerosis manifested as decreased arterial wall elasticity. Degree of stiffening was associated with advancement of atherosclerosis in their parents but did not present significant association with gene variants. Sonography with application of 2DST seems to be a good candidate for comprehensive evaluation of atherosclerosis in families with FH.

Two-Dimensional Speckle Tracking Versus Applanation Tonometry in Evaluation of Subclinical Atherosclerosis in Children with Type 1 Diabetes Mellitus

Background

Patients with type 1 diabetes mellitus (T1DM) often develop atherosclerosis at an early age. In the subclinical stage of the process, minimal/non-morphological changes can be noticed, but the arterial wall function can be impaired. Applanation tonometry allows to assess the arterial tree stiffness; however, the Two-Dimensional Speckle Tracking (2DST) is an increasingly accepted alternative. This study evaluated arterial wall stiffness using these 2 techniques in children with T1DM.

Material/Methods

We performed applanation tonometry and carotid arteries sonography with evaluation of the carotid intima-media thickness (cIMT) and use of the 2DST in 50 children with T1DM and in 50 healthy sex- and age-matched controls. We also assessed the reliability of 2DST in 10 random subjects.

Results

Children with T1DM had increased arterial wall stiffness, which was confirmed by tonometry (PWV: p=0.0386) and 2DST (Strain: p=0.0004; Strain rate: p=0.0081). There was no significant difference in cIMT between groups (0.45±0.06 vs. 0.43±0.05, p=0.073 in children with T1DM and controls, respectively). 2DST presented good intraclass correlation coefficient between researchers and within a single researcher.

Conclusions

Children with T1DM presenting with subclinical stage of atherosclerosis were found to have arterial wall stiffening. The 2DST, the same as applanation tonometry, allows to recognize this condition but in a more accessible and reproducible manner.

Arterial stiffness is associated with target organ damage in subjects with pre-hypertension

INTRODUCTION

Present study was to evaluate whether increased arterial stiffness was associated with target organ damage in pre-hypertensive subjects.

MATERIAL AND METHODS

Pre-hypertensive subjects enrolled and echocardiography was used to evaluate left ventricular hypertrophy (LVH) and the first morning urine was collected to evaluate albumin and creatinine ratio (ALB/Cr ratio). Carotid-femoral pulse wave velocity (cf-PWV) was measured.

RESULTS

A total of 420 subjects were recruited and mean age was 42.6 years. Mean systolic/diastolic blood pressure (SBP/DBP) were 130 ±9 mm Hg and 85 ±4 mm Hg. The prevalence of albuminuria and left ventricular hypertrophy was 8.6 % and 11.7 %. Mean cf-PWV was 9.2 ±1.0 m/s, with arterial stiffness prevalence was 8.8%. Subjects with arterial stiffness had higher cf-PWV value (10.6 ±0.4 m/s vs. 8.7 ±0.6 m/s, p < 0.05), and ALB/Cr ratio (28.3 ±13.2 µg/mg vs. 23.1 ± 11.4 µg/mg, p < 0.05). Overall, with multivariate regression analysis, aging and arterial stiffness were significantly associated with pre-hypertension. With stepwise adjusted for potential covariates including age, male gender, fasting plasma glucose, presence of current cigarette smoking, dyslipidemia, statins and SBP, increased cf-PWV remained independently associated with left ventricular hypertrophy and albuminuria, with an increased odds of 41 % and 24 % (p < 0.05), respectively.

CONCLUSIONS

In pre-hypertensive subjects, arterial stiffness is independently associated with LVH and albuminuria and cf-PWV may be a useful marker to identify target organ damage in pre-hypertensive subjects.

Impairment of vascular strain in patients with obstructive sleep apnea

Background

Obstructive sleep apnea (OSA) is an independent risk factor for the development of cardiovascular diseases. Aim of this present study was to evaluate and extend recent research on the influence of obstructive sleep apnea on vascular strain.

Methods

A total number of 98 patients were integrated in the study. Patients were grouped according to the Apnea-Hypopnea-Index (AHI) in patients with mild-to-moderate OSA (5/h ≤ AHI < 30/h), severe OSA (AHI ≥ 30/h) and controls (AHI < 5/h). Groups were matched in age, body-mass-index and cardiovascular risks. Vascular strain of common carotid arteries was assessed by ultrasound speckle-tracking. A minor group of 30 patients and controls further underwent assessment of vascular strain of brachial and femoral arteries. Additionally, all patients underwent blood testing to reveal potential influences of inflammatory markers on arterial stiffness. In additional analysis we examined the effect of statin therapy on vascular strain.

Results

Patients with OSA showed significantly reduced values of vascular strain of common carotid arteries. Radial and circumferential strains were significantly lower in both patients with mild-to-moderate (p = .05) and patients with severe OSA (p = .001) compared to control. Vascular strain parameters of brachial and femoral arteries showed no consistent results. There were no significant correlations of inflammatory markers with vascular strain parameters. No significant differences in vascular strain were detected between statin and non-statin groups.

Conclusion

Patients with OSA show significantly reduced vascular strain assessed by ultrasound-based speckle-tracking. Vascular stiffness increases with the severity of the disease. Target vessels to assess vascular strain in patients with OSA are common carotid arteries, whereas other sites of the arterial tree are not reliable. No significant impact of current statin therapy on vascular strain was found. Further studies are needed to evaluate potential benefit of statins in secondary prevention of atherosclerosis in OSA.

Carotid strain measurement in patients with pseudoxanthoma elasticum - Hint for a different pathomechanism?

Pseudoxanthoma Elasticum (PXE), caused by autosomal-recessive mutations in the ATP-binding cassette transporter (ABCC6) gene, is known for high prevalence of atherosclerosis. A novel method investigating elastic properties of arteries in atherosclerotic patients is vascular strain analysis. We compared 44 PXE patients with peripheral artery disease (PXE+PAD group) with 50 control patients, each 25 without (control group) and with PAD (PAD group). All participants underwent an angiological examination including ankle-brachial index (ABI) and were examined with speckle-tracking based vascular strain analysis of common carotid arteries, measuring radial displacement (r.Dis), radial velocity (r.Vel), radial strain (r.Str), circumferential strain (c.Str), radial strainrate (r.SR) and circumferential strainrate (c.SR). We found significant lower ABI in patients with PXE compared to all other groups (each p < 0.01). The vascular strain analysis resulted in significantly decreased values in the PAD group compared to PXE with PAD (each p ≤ 0.01) and controls without PAD (each p ≤ 0.05), whereas no significant difference could be found between PXE+PAD and controls without PAD. We found significant negative correlations between low strain values and a higher prevalence of PAD in non-PXE patients (r.Str r = -0.34; c.Str r = -0.35; r.SR: r = -0.51; c.SR: r = -0.53). In conclusion, PXE patients had similar values for arterial stiffness compared to controls without PAD in vascular strain analysis. In this group, arterial stiffness parameters were significantly higher compared to non-PXE PAD patients. It is worth to discuss whether PAD-like manifestations in PXE are a different kind of disease and might need another strategy in diagnostics and therapy.

Feasibility of two-dimensional speckle tracking in evaluation of arterial stiffness: Comparison with pulse wave velocity and conventional sonographic markers of atherosclerosis

Objective Arterial stiffening is an early marker of atherosclerosis that has a prognostic value for cardiovascular morbidity and mortality. Although many markers of arterial hardening have been proposed, the search is on for newer, more user-friendly and reliable surrogates. One such potential candidate has emerged from cardiology, the speckle-tracking technique. The aim of this study was to evaluate the feasibility of the two-dimensional speckle tracking for the evaluation of arterial wall stiffness in comparison with standard stiffness parameters. Methods Carotid ultrasound and applanation tonometry were performed in 188 patients with no cardiovascular risk factors. The following parameters were then evaluated: the intima-media complex thickness, distensibility coefficient, β-stiffness index, circumferential strain/strain rate, and pulse wave velocity and augmentation index. These variables were compared with each other and with patient age, and their reliability was assessed with Bland-Altman plots. Results Strain parameters derived from two-dimensional speckle tracking and intima-media complex thickness correlated better with age and pulse wave velocity than standard makers of arterial stiffness. Moreover, the reliability of these measurements was significantly higher than conventional surrogates. Conclusions Two-dimensional speckle tracing is a reliable method for the evaluation of arterial stiffness. Therefore, together with intima-media complex thickness measurement, it offers great potential in clinical practice as an early marker of atherosclerosis.

Does the internal jugular vein affect the elasticity of the common carotid artery?

Background

Arterial stiffness is an early marker of atherosclerosis. The carotid arteries are easily accessible by ultrasound and are commonly used for the evaluation of atherosclerosis development. However, this stiffness assessment is based on the elastic properties of the artery, which may be influenced by the adjacent internal jugular vein (IJV).

The aim of the present study is to evaluate the influence of internal jugular vein morphology on the stiffness of the common carotid artery.

Methods

Bilateral carotid ultrasound was performed in 248 individuals. When no carotid plaque was detected (90.9 % cases), the distensibility coefficient and β - stiffness index were calculated. The global and segmental circumferential strain parameters of the carotid wall were evaluated with 2D-Speckle Tracking. The cross-sectional area of the IJV and degree of its adherence to the carotid wall (angle of adherence) were measured.

Results

The morphology of the IJV did not influence the standard stiffness parameters nor the global circumferential strain. However, segmental analysis found the sector adjacent to the IJV to have significantly higher strain parameters than its opposite counterpart. In addition, the strain correlated significantly and positively with IJV cross-sectional area and angle of adherence.

Conclusions

The movement of the carotid artery wall caused by the passage of the pulse wave is not homogeneous. The greatest strain is observed in a segment adjacent to the IJV, and the degree of wall deformation is associated with the size of the vein and the degree of its adherence.

Circumferential strain of carotid arteries does not differ between patients with advanced coronary artery disease and group without coronary stenoses

PURPOSE

Speckle tracking echocardiography is widely used for the analysis of myocardial function. Recently, circumferential strain (CS) of carotid arteries was postulated as novel indicator of vascular function. Our aim was to characterize and compare CS of carotid arteries in patients with advanced coronary artery disease and controls without significant coronary stenoses.

PATIENTS/METHODS

We compared CS of both common carotid arteries (CCA) in the 25 patients with three-vessel coronary artery disease (3VD) (mean age 69±9 years, 9 male) and in 16 age-matched subjects without significant coronary lesions (C) (69±8 years, 7 male). Additionally in 11 patients we estimated pulse wave velocity (PWV) and assessed the correlation between PWV and CS. Short-axis images of arteries were acquired for strain analysis with linear probe of echocardiograph. The assessment of CS was performed off-line by two observers.

RESULTS

The intraobserver variability for the CS (coefficient of variation) were 4.9 and 5.4% for left and right CCA and interobserver variability were 11.7% and 12.5%, respectively. The mean CS for left and right CCA did not differ between compared groups. We did not find correlation between CS strain and PWV. The only difference was related to the more prevalent plaque presence and thicker intima-media complex (IMT) in 3VD (p=0.0039 for IMT of left CCA and p=0.016 for IMT of right CCA).

CONCLUSIONS

The global CS of CCA, contrary to IMT, did not allow for differentiation between 3VD and C subjects. Despite good feasibility and concordance of CS measurements its clinical significance remains to be established.

Inhibition of endoplasmic reticulum stress improves coronary artery function in the spontaneously hypertensive rats

Endoplasmic reticulum (ER) stress has been shown to play a critical role in the pathogenesis of cardiovascular complications. However, the role and mechanisms of ER stress in hypertension remain unclear. Thus, we hypothesized that enhanced ER stress contributes to the maintenance of hypertension in spontaneously hypertensive rats (SHRs). Sixteen-week old male SHRs and Wistar Kyoto Rats (WKYs) were used in this study. The SHRs were treated with ER stress inhibitor (Tauroursodeoxycholic acid; TUDCA, 100 mg/kg/day) for two weeks. There was a decrease in systolic blood pressure in SHR treated with TUDCA. The pressure-induced myogenic tone was significantly increased, whereas endothelium-dependent relaxation was significantly attenuated in SHR compared with WHY. Interestingly, treatment of ER stress inhibitor normalized myogenic responses and endothelium-dependent relaxation in SHR. These data were associated with an increase in expression or phosphorylation of ER stress markers (Bip, ATF6, CHOP, IRE1, XBP1, PERK, and eIF2α) in SHRs, which were reduced by TUDCA treatment. Furthermore, phosphorylation of MLC20 was increased in SHRs, which was reduced by the treatment of TUDCA. Therefore, our results suggest that ER stress could be a potential target for hypertension.

Effect of comprehensive cardiovascular disease risk management on longitudinal changes in carotid artery intima-media thickness in a community-based prevention clinic

INTRODUCTION

The aim of the study was to examine changes in carotid intima-media thickness (CIMT) and carotid plaque morphology in patients receiving multifactorial cardiovascular disease (CVD) risk factor management in a community-based prevention clinic. Quantitative changes in CIMT and qualitative changes in carotid plaque morphology may be measured non-invasively by ultrasound.

MATERIAL AND METHODS

This is a retrospective study on a cohort of 324 patients who received multifactorial cardiovascular risk reduction treatment at a community prevention clinic. All patients received lipid-lowering medications (statin, niacin, and/or ezetimibe) and lifestyle modification. All patients underwent at least one follow-up CIMT measurement after starting their regimen. Annual biomarker, CIMT, and plaque measurements were analyzed for associations with CVD risk reduction treatment.

RESULTS

Median time to last CIMT was 3.0 years. Compared to baseline, follow-up analysis of all treatment groups at 2 years showed a 52.7% decrease in max CIMT, a 3.0% decrease in mean CIMT, and an 87.0% decrease in the difference between max and mean CIMT (p < 0.001). Plaque composition changes occurred, including a decrease in lipid-rich plaques of 78.4% within the first 2 years (p < 0.001). After the first 2 years, CIMT and lipid-rich plaques continued to decline at reduced rates.

CONCLUSION

In a cohort of patients receiving comprehensive CVD risk reduction therapy, delipidation of subclinical carotid plaque and reductions in CIMT predominantly occurred within 2 years, and correlated with changes in traditional biomarkers. These observations, generated from existing clinical data, provide unique insight into the longitudinal on-treatment changes in carotid plaque.

Identification of Angiogenesis Rich-Viable Myocardium using RGD Dimer based SPECT after Myocardial Infarction

Cardiac healing after myocardial ischemia is a complex biological process. Advances in understanding of wound healing response have paved the way for clinical testing of novel molecular imaging to improve clinical outcomes. A key factor for assessing myocardial viability after ischemic injury is the evaluation of angiogenesis accompanying increased expression of integrin αvβ3. Here, we describe the capability of an αvβ3 integrin-targeting SPECT agent, (99m)Tc-IDA-D-[c(RGDfK)]2, for identification of ischemic but viable myocardium, i.e., hibernating myocardium which is crucial to predict functional recovery after revascularization, the standard care of cardiovascular medicine. In vivo SPECT imaging of rat models with transient coronary occlusion showed significantly high uptake of (99m)Tc-IDA-D-[c(RGDfK)]2 in the ischemic region. Comparative measurements with (201)Tl SPECT and (18)F-FDG PET, then, proved that such prominent uptake of (99m)Tc-IDA-D-[c(RGDfK)]2 exactly matched the hallmark of hibernation, i.e., the perfusion-metabolism mismatch pattern. The uptake of (99m)Tc-IDA-D-[c(RGDfK)]2 was non-inferior to that of (18)F-FDG, confirmed by time-course variation analysis. Immunohistochemical characterization revealed that an intense signal of (99m)Tc-IDA-D-[c(RGDfK)]2 corresponded to the vibrant angiogenic events with elevated expression of αvβ3 integrin. Together, these results establish that (99m)Tc-IDA-D-[c(RGDfK)]2 SPECT can serve as a sensitive clinical measure for myocardial salvage to identify the patients who might benefit most from revascularization.