Preclinical carotid atherosclerosis as an indicator of polyvascular disease: a narrative review

An Investigation of Metabolic Risk Factors and Gut Microbiota in Unexplained Syncope

BACKGROUND

The pathogenesis of many syncopal episodes remains unexplained. Intestinal dysbiosis could be involved in the pathophysiological mechanisms of syncope due to its connection with the central nervous system via the microbiota-gut-brain axis. This pilot study aimed to explore the specific cardiometabolic risk factors and gut microbiota in unexplained syncope (US), compared to other types of syncope, to assess their similarity or verify their different origins.

METHODS

We studied 86 participants with syncope, who were divided into four groups: an orthostatic syncope group (OH, n = 24), a neuromediated syncope group (NMS, n = 26), a cardiological syncope group (CS, n = 9), and an unexplained syncope group (US, n = 27). We evaluated the anthropometric, clinical, and metabolic characteristics of the four groups; the α- and β-diversity; and the differences in the abundance of the microbial taxa.

RESULTS

The US group had a lower incidence of systolic hypertension at the first visit and a lower frequency of patients with nocturnal hypertension than the CS group. Compared to the OH and NMS groups, the US group had a higher incidence of carotid plaques and greater carotid intima-media thickness, respectively. The microbiota differed significantly between the US and CS groups, but not between the US group and the OH or NMS group.

CONCLUSIONS

We observed significant differences in the gut microbiota between CS and US. Future studies are necessary to evaluate the involvement of the gut microbiota in the complex pathogenesis of syncope and whether its analysis could support the interpretation of the pathophysiological mechasnisms underlying some episodes classifiable as US.

Risk Factors for Ankle Brachial Index and Carotid Artery Stenosis in Patients with Type 2 Diabetes

Type 2 diabetes mellitus (T2DM) significantly increases the risk of atherosclerotic cardiovascular disease. Ankle brachial index (ABI) and carotid artery stenosis are non-invasive indicators of generalized atherosclerosis. This study aimed to explore the risk factors for ABI and carotid artery stenosis and discover which factors simultaneously influence both conditions in T2DM. The study included a total of 101 patients with T2DM. ABI was performed via Doppler ultrasound, and both common carotid arteries were examined via ultrasound to obtain the percentage of carotid artery stenosis. A negative correlation was noted between the ABI and the percentage of carotid artery stenosis (p = 0.043). ABI correlated significantly negatively with waist circumference (p = 0.031), total cholesterol (p = 0.003), low-density lipoprotein (LDL) cholesterol (p = 0.003), and C-reactive protein (CRP) (p = 0.017), whereas the percentage of carotid artery stenosis correlated with the smoking habit (p = 0.017) and CRP (p = 0.042). The best model for predicting the ABI value (R2 = 0.195) obtained from stepwise regression analysis included waist circumference, LDL cholesterol, triglycerides, and CRP, while the best model for the percentage of the carotid artery stenosis (R2 = 0.112) included smoking and CRP. CRP influenced the ABI value with a negative parameter estimate of -0.008962 (p = 0.053) and the percentage of the carotid artery stenosis with a positive parameter estimate of 0.443655 (p = 0.006) relative to a one-unit change of it, presenting the negatively significant impact of CRP on the association between carotid artery stenosis and low ABI. Our results suggest that CRP is the most important risk factor that connects ABI and carotid artery stenosis, which are important non-invasive indicators of generalized atherosclerosis in T2DM.

Clinical significance of carotid intima-media thickness and plasma homocysteine in acute ST-segment elevation myocardial infarction

Background

Patients with acute ST-segment elevation myocardial infarction (STEMI) often have fewer identifiable traditional risk factors compared to other types of acute coronary syndrome. Therefore, it is necessary to explore more sensitive predictive models different from traditional cardiovascular scoring systems to identify high-risk populations. The retrospective case-control study aimed to investigate the predictive value of carotid intima-media thickness (CIMT) and homocysteine (Hcy) on the occurrence of STEMI.

Methods

A total of 198 patients with first STEMI were continuously selected into the observation group, who received emergency coronary angiography in Hefei Hospital Affiliated to Anhui Medical University from January 2020 to January 2022, and a total of 129 patients with chest pain and chest tightness who received coronary angiography to exclude significant coronary artery disease were selected as the control group in the above hospitals during the same period. Hcy was biochemical index determined by fasting blood sampling within 48 h after admission, while CIMT and carotid plaque was measured using ultrasound. Univariate and multivariate logistic regression analysis was used to screen out independent risk factors including Hcy, CIMT and carotid plaque of STEMI. On the basis of traditional risk factors, Hcy, CIMT and carotid plaque were introduced in order to form different combined diagnosis models. The receiver operating characteristic (ROC) curve of single indicator and multi-indicator combined diagnosis were plotted to evaluate the clinical usefulness of the study factors or diagnostic models. Based on those, a Nomogram was constructed to predict STEMI.

Results

Hcy (OR =1.161, 95% CI: 1.084-1.244, P<0.001), CIMT (OR =206.968, 95% CI: 22.375-1,914.468, P<0.001), carotid plaque (OR =2.499, 95% CI: 1.214-5.142, P=0.013) were independent risk factors for STEMI (P<0.01). ROC results suggested that the area under the curve (AUC) of Hcy was 0.729, the optimal cut-off value was 13.525 µmol/L. The AUC of CIMT is 0.763, and the optimal cut-off value is 0.875mm. Combined with the independent predictors including smoking, diabetes, high density lipoprotein cholesterol, low density lipoprotein cholesterol, Hcy, CIMT, carotid plaque, the AUC of the diagnosis model was 0.892 (95% CI: 0.856-0.928, P<0.001). Based on the above results, a Nomogram for predicting STEMI was constructed with a C-index of 0.892. The results of the H-L fitting test show that χ2=1.5049, df=2, P=0.4712; the calibration curve of the Nomogram is close to the ideal curve, and the internal validation C-index was 0.880. The clinical decision curve analysis (DCA) shows that the "nomogram line" of the model is far from the "All line" and the "None line".

Conclusions

Hcy, CIMT, and carotid artery plaque could be independent risk factors of STEMI. The inclusion of these factors in addition to traditional risk factors can more fully and accurately predict the risk of STEMI. The Nomogram based on the results of this study is feasible and can bring clinical net benefit.

Heterogeneous Carotid Plaque Predicts Cardiovascular Events after Percutaneous Coronary Intervention

AIM

The relationship between carotid artery ultrasound findings and clinical outcomes in patients who undergo percutaneous coronary intervention (PCI) has not been completely elucidated.

METHODS

This single-center retrospective study investigated 691 patients who underwent PCI and carotid ultrasound testing. Maximum carotid intima-media thickness (CIMT) was defined as the greatest CIMT at the maximally thick point among the common carotid artery, carotid bulb, and internal carotid artery. A carotid plaque was defined as vessel wall thickening with a CIMT ≥ 1.5 mm. The characteristics of carotid plaque (heterogeneity, calcification, or irregular/ulcerated surface) were evaluated visually. Patients were divided into those with and without heterogeneous carotid plaque (maximum CIMT ≥ 1.5 mm and heterogeneous texture). The endpoint was the incidence of a major adverse cardiovascular event (MACE) defined as a composite of cardiovascular (CV) death, myocardial infarction, and ischemic stroke.

RESULTS

Among 691 patients, 309 were categorized as having a heterogeneous plaque. Patients with heterogeneous plaques were at a higher risk of MACE than those without (p=0.002). A heterogeneous plaque was independently associated with MACE after adjusting for covariates (hazard ratio [HR], 1.71; 95% confidence interval [CI], 1.01-2.90; p=0.046). Calcified or irregular/ulcerated plaques were correlated with a higher incidence of MACE, but both were not independently associated with MACE (HR, 1.35; 95% CI, 0.69-2.64, p=0.38 and HR, 0.98; 95% CI, 0.57-1.69; p=0.95, respectively).

CONCLUSION

The presence of a heterogeneous carotid plaque in patients who underwent PCI predicted future CV events. These patients may require more aggressive medical therapy and careful follow-up.

Comparison of Functional and Morphological Estimates of Vascular Age

BACKGROUND/AIM

Vascular age (VA) is an emerging metric in preventive cardiovascular (CV) medicine. VA can be derived from morphological parameters such as carotid intima-media thickness (CIMT), or functional parameters such as pulse wave analysis (PWA), which celebrates its 100th birthday. This study aimed to investigate whether the results of both approaches are comparable.

PATIENTS AND METHODS

On the occasion of the double 100th anniversary of PWA and the Mannheim Clinic, 100 volunteers underwent a) bilateral CIMT assessment using high-resolution ultrasound and b) oscillometric PWA at the brachial forearm site. The respective VAs were calculated using previously published equations.

RESULTS

Median age of the participants was 53.6 years (range=39.8-62.6 years), and 56% were female. Median CIMT was 632.5 μm (range=548.8-730.0 μm). Median PWA-derived VA was 55.3 years (36.5-70.5 years). Different values were obtained for CIMT-derived VA, depending on the reference cohort used as calculation basis, ranging from median 43.7 (26.2-59.5 years) to median 64.0 years (43.5-82.1 years). In 46% of the participants divergent VAs were found, that is, the calculated age was higher according to one method and lower according to the other. Correlation analysis revealed a strong dependence of VA (both PWA- and CIMT-derived) and chronological age, as well as an increase in CV risk factors and the detection of plaques with age.

CONCLUSION

Different approaches for estimating VA are not comparable and often produce contradictory results. The current methods and their validity must be critically assessed if they are not standardized.

Analysis of Risk Factors for Vulnerable Plaque Formation and Pathogenic in Carotid Artery

OBJECTIVES

The formation of vulnerable carotid artery plaque may be closely related to a single factor or caused by multiple factors. This paper discusses the pathogenic risk factors for vulnerable plaque in patients with severe internal carotid artery (ICA) stenosis who received endarterectomy through regression analysis.

MATERIALS AND METHODS

A total of 98 patients with a complete clinical and laboratory assessment underwent carotid endarterectomy. Metabolic syndrome (MetS) and MetS components, ICA plaque thickness and ICA peak systolic velocity, previous ischemic stroke or transient ischemic attack (TIA), and other risk factors were included in the pathogenic risk factor for vulnerable plaque. Univariate logistic regression analysis was used to determine vulnerable carotid plaque risk factors. If P <0.2, it was considered potential confounders. Binary logistic regression model was controlled for potential confounders.

RESULTS

Among the 98 patients, stable carotid plaques 38 (39%) and unstable carotid plaques 60 (61%), male 76 (77.6%) and female 22 (22.4%), and Han Chinese 68 (68.4%) and Mongols 30 (30.6%). Univariate logistic regression to P <0.2 has 6 risk factors, which are previous ischemic stroke or TIA, ICA peak systolic velocity, ICA plaque thickness, body mass index, total cholesterol, and alcohol consumption. The significant result of the binary logistic regression analysis was the previous ischemic stroke or TIA (OR=4.52; 95% CI, 1.67-12.09), P =0.003 and ICA peak systolic velocity (OR=1.01; 95% CI, 1.00-1.02), P =0.014.

CONCLUSIONS

The patients with previous ischemic stroke or TIA and higher ICA peak systolic velocity are associated with vulnerable plaque pathogenic features. There is no obligatory association between MetS and formation of carotid plaque vulnerability.

Carotid total plaque area as an independent predictor of short-term subclinical polyvascular atherosclerosis progression and major adverse cardiac and cerebrovascular events

BACKGROUND

The use of ultrasound-based methods for imaging of subclinical atherosclerosis, including measurement of carotid plaque burden (cPB), is a promising direction for further improvement of major adverse cardiac and cerebrovascular events (MACCE) prediction.

OBJECTIVES

The aim of the study was to research the prognostic values' significance of cPB indicators with regard to the short-term progression of polyvascular subclinical atherosclerosis and the long-term onset of MACCE.

DESIGN

Single-center prospective cohort study.

METHODS

The study included patients 40-64 years of age. All patients underwent duplex scanning (DS) of the carotid and lower limb arteries. The following cPB indicators were determined: carotid plaque score (cPS), maximum carotid plaque thickness (cPTmax), and carotid total plaque area (cTPA). The combined endpoint included the following components: cardiovascular death; nonfatal myocardial infarction; nonfatal stroke or transient ischemic attack (TIA); revascularization of the coronary and/or peripheral arteries.

RESULTS

The study included 387 patients, among whom 142 (36.7%) patients underwent repeated DS after 12-24 months. The median follow-up time was 20.0 (13.0; 36.5) months. MACCE were recorded in 33 (8.52%) of patients. cTPA and cPTmax, but not cPS, were independently associated with the progression of subclinical polyvascular atherosclerosis over a period of 13.9 months of follow-up. cTPA, but not cPTmax and cPS, was independently associated with the development of MACCE over a period of 20.0 months of follow-up. Only a cTPA > 42.0 mm2 proved to be an independent predictor of both the progression of subclinical polyvascular atherosclerosis and MACCE.

CONCLUSION

In patients from 40 to 64 years of age with various cardiovascular risks, among the indicators of the cPB, only an increase in cTPA > 42.0 mm2 was shown to be independently associated with an increase in the relative risk (RR) of progression of subclinical polyvascular atherosclerosis by 2.38 (1.08-5.25) times, as well as with the development of MACCE by 3.10 (1.54-6.26) times.

Patients with Polyvascular Disease: A Very High-risk Group

Polyvascular disease (PolyvascDis) with atherosclerosis occurring in >2 vascular beds (coronary, carotid, aortic, visceral and/or peripheral arteries) is encountered in 15-30% of patients who experience greater rates of major adverse cardiovascular (CV) events. Every patient with multiple CV risk factors or presenting with CV disease in one arterial bed should be assessed for PolyvascDis clinically and noninvasively prior to invasive angiography. Peripheral arterial disease (PAD) can be readily diagnosed in routine practice by measuring the ankle-brachial index. Carotid disease can be diagnosed by duplex ultrasound showing % stenosis and/or presence of plaques. Coronary artery disease (CAD) can be screened by determining coronary artery calcium score using coronary computed tomography angiography; further, non-invasive testing includes exercise stress and/or myocardial perfusion imaging or dobutamine stress test, prior to coronary angiography. Abdominal ultrasound can reveal an abdominal aortic aneurysm. Computed tomography angiography will be needed in patients with suspected mesenteric ischemia to assess the mesenteric arteries. Patients with the acute coronary syndrome and concomitant other arterial diseases have more extensive CAD and poorer CV outcomes. Similarly, PolyvascDis in patients with carotid disease and/or other PAD is independently associated with an increased risk for all-cause and CV mortality during long-term follow-up. Treatment of patients with PolyvascDis should include aggressive management of all modifiable risk factors by lifestyle changes and drug therapy, with particular attention to patients who are commonly undertreated, such as those with PAD. Revascularization should be reserved for symptomatic vascular beds, using the least aggressive strategy in a multidisciplinary vascular team approach.

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.

Vitamin C Intake and Ischemic Stroke

Vitamin C is an essential micronutrient with important antioxidant properties. Ischemic stroke is a major public health problem worldwide. Extensive evidence demonstrates that vitamin C has protective effects against cardiovascular disease, and there is a close relationship between vitamin C intake and ischemic stroke risk. Based on the evidence, we conducted this umbrella review to clarify the relationship between vitamin C intake and ischemic stroke risk from four perspectives: cellular mechanisms, animal experiments, clinical trials, and cohort studies.