Correlation between risk factors of cerebrovascular disease and calcified plaque characteristics in patients with atherosclerotic severe carotid stenosis

Association of cardiovascular risk factors and intraplaque neovascularization in symptomatic carotid plaque

Background and purpose

Cardiovascular risk factors are known to contribute to the formation of atherosclerotic plaques, which can result in carotid stenosis. However, the extent to which these factors are associated with intraplaque neovascularization, a key indicator of plaque vulnerability, remains unclear. To investigate this relationship, a study was conducted utilizing contrast-enhanced ultrasound (CEUS) to assess intraplaque neovascularization in symptomatic patients.

Methods

A cohort of 157 symptomatic patients underwent evaluation using Contrast-Enhanced Ultrasound (CEUS) imaging to assess carotid intraplaque neovascularization, which was quantified based on the degree of plaque enhancement. The collected data encompassed baseline patient characteristics, results from biochemical examinations, cardiovascular risk factors, and medication usage history. Regression analyses were conducted to elucidate the relationship between carotid plaque neovascularization and various cardiovascular risk factors.

Results

Patients with intraplaque neovascularization were more prone to have diabetes mellitus (OR 3.81, 95% CI 1.94-7.46, p < 0.001), dyslipidemia (OR 2.36, 95% CI 1.22-4.55, p = 0.011) and hypertension (OR 2.92, 95% CI 1.50-5.71, p = 0.002). Smoking increased the risk of having intraplaque neovascularization (OR 2.25, 95% CI 1.12-4.54, p = 0.023). Treatment with statins was significantly lower in patients with intraplaque neovascularization (OR 0.37, 95% CI 0.19-0.72, p = 0.003). In the multivariate analysis, diabetes mellitus (OR 3.27, 95% CI 1.10-9.78, p = 0.034) was independently related to the presence of intraplaque neovascularization. Meanwhile, compared to the patients in the first tertile of serum glucose (< 6.20 mmol/L), the patients in the third tertile (> 13.35 mmol/L) had the most significance of intraplaque neovascularization (OR 5.55, 95% CI 1.85-16.66, p = 0.002).

Conclusion

The findings indicated that diabetes mellitus is a significant cardiovascular risk factor that is strongly associated with carotid intraplaque neovascularization.

Effects of plaque characteristics and artery hemodynamics on the residual stenosis after carotid artery stenting

OBJECTIVE

Carotid artery stenting (CAS) has become an alternative strategy to carotid endarterectomy for carotid artery stenosis. Residual stenosis was an independent risk factor for restenosis, with the latter affecting the long-term outcomes of CAS. This multicenter study aimed to evaluate the echogenicity of plaques and hemodynamic alteration by color duplex ultrasound (CDU) examination and investigate their effects on the residual stenosis after CAS.

METHODS

From June 2018 to June 2020, 454 patients (386 males and 68 females) with a mean age of 67.2 ± 7.9 years, who underwent CAS from 11 advanced stroke centers in China were enrolled. One week before recanalization, CDU was used to evaluate the responsible plaques, including the morphology (regular or irregular), echogenicity of the plaques (iso-, hypo-, or hyperechoic) and calcification characteristics (without calcification, superficial calcification, inner calcification, and basal calcification). One week after CAS, the alteration of diameter and hemodynamic parameters were evaluated by CDU, and the occurrence and degree of residual stenosis were determined. In addition, magnetic resonance imaging was performed before and during the 30-day postprocedural period to identify new ischemic cerebral lesions.

RESULTS

The rate of composite complications, including cerebral hemorrhage, symptomatic new ischemic cerebral lesions, and death after CAS, was 1.54% (7/454 cases). The rate of residual stenosis after CAS was 16.3% (74/454 cases). After CAS, both the diameter and peak systolic velocity (PSV) improved in the preprocedural 50% to 69% and 70% to 99% stenosis groups (P < .05). Compared with the groups without residual stenosis and with <50% residual stenosis, the PSV of all three segments of stent in the 50% to 69% residual stenosis group were the highest, and the difference in the midsegment of stent PSV was the largest (P < .05). Logistic regression analysis showed that preprocedural severe (70% to 99%) stenosis (odds ratio [OR], 9.421; P = .032), hyperechoic plaques (OR, 3.060; P = .006) and plaques with basal calcification (OR, 1.885; P = .049) were independent risk factors for residual stenosis after CAS.

CONCLUSIONS

Patients with hyperechoic and calcified plaques of the carotid stenosis are at a high risk of residual stenosis after CAS. CDU is an optimal, simple and noninvasive imaging method to evaluate plaque echogenicity and hemodynamic alterations during the perioperative period of CAS, which can help surgeons to select the optimal strategies and prevent the occurrence of residual stenosis.

Nicotine promotes vascular calcification via intracellular Ca2+-mediated, Nox5-induced oxidative stress and extracellular vesicle release in vascular smooth muscle cells

Aims

Smokers are at increased risk of cardiovascular events. However, the exact mechanisms through which smoking influences cardiovascular disease resulting in accelerated atherosclerosis and vascular calcification are unknown. The aim of this study was to investigate effects of nicotine on initiation of vascular smooth muscle cell (VSMC) calcification and to elucidate underlying mechanisms.

Methods and results

We assessed vascular calcification of 62 carotid lesions of both smoking and non-smoking patients using ex vivo micro-computed tomography (µCT) scanning. Calcification was present more often in carotid plaques of smokers (n = 22 of 30, 73.3%) compared to non-smokers (n = 11 of 32, 34.3%; P < 0.001), confirming higher atherosclerotic burden. The difference was particularly profound for microcalcifications, which was 17-fold higher in smokers compared to non-smokers. In vitro, nicotine-induced human primary VSMC calcification, and increased osteogenic gene expression (Runx2, Osx, BSP, and OPN) and extracellular vesicle (EV) secretion. The pro-calcifying effects of nicotine were mediated by Ca²⁺-dependent Nox5. SiRNA knock-down of Nox5 inhibited nicotine-induced EV release and calcification. Moreover, pre-treatment of hVSMCs with vitamin K2 ameliorated nicotine-induced intracellular oxidative stress, EV secretion, and calcification. Using nicotinic acetylcholine receptor (nAChR) blockers α-bungarotoxin and hexamethonium bromide, we found that the effects of nicotine on intracellular Ca²⁺ and oxidative stress were mediated by α7 and α3 nAChR. Finally, we showed that Nox5 expression was higher in carotid arteries of smokers and correlated with calcification levels in these vessels.

Conclusion

In this study, we provide evidence that nicotine induces Nox5-mediated pro-calcific processes as novel mechanism of increased atherosclerotic calcification. We identified that activation of α7 and α3 nAChR by nicotine increases intracellular Ca²⁺ and initiates calcification of hVSMCs through increased Nox5 activity, leading to oxidative stress-mediated EV release. Identifying the role of Nox5-induced oxidative stress opens novel avenues for diagnosis and treatment of smoking-induced cardiovascular disease.

Monitoring and Prognostic Analysis of Severe Cerebrovascular Diseases Based on Multi-Scale Dynamic Brain Imaging

Severe cerebrovascular disease is an acute cerebrovascular event that causes severe neurological damage in patients, and is often accompanied by severe dysfunction of multiple systems such as breathing and circulation. Patients with severe cerebrovascular disease are in critical condition, have many complications, and are prone to deterioration of neurological function. Therefore, they need closer monitoring and treatment. The treatment strategy in the acute phase directly determines the prognosis of the patient. The case of this article selected 90 patients with severe cerebrovascular disease who were hospitalized in four wards of the Department of Neurology and the Department of Critical Care Medicine in a university hospital. The included cases were in accordance with the guidelines for the prevention and treatment of cerebrovascular diseases. Patients with cerebral infarction are given routine treatments such as improving cerebral circulation, protecting nutrient brain cells, dehydration, and anti-platelet; patients with cerebral hemorrhage are treated within the corresponding safe time window. We use Statistical Product and Service Solutions (SPSS) Statistics21 software to perform statistical analysis on the results. Based on the study of the feature extraction process of convolutional neural network, according to the hierarchical principle of convolutional neural network, a backbone neural network MF (Multi-Features)—Dense Net that can realize the fusion, and extraction of multi-scale features is designed. The network combines the characteristics of densely connected network and feature pyramid network structure, and combines strong feature extraction ability, high robustness and relatively small parameter amount. An end-to-end monitoring algorithm for severe cerebrovascular diseases based on MF-Dense Net is proposed. In the experiment, the algorithm showed high monitoring accuracy, and at the same time reached the speed of real-time monitoring on the experimental platform. An improved spatial pyramid pooling structure is designed to strengthen the network’s ability to merge and extract local features at the same level and at multiple scales, which can further improve the accuracy of algorithm monitoring by paying a small amount of additional computational cost. At the same time, a method is designed to strengthen the use of low-level features by improving the network structure, which improves the algorithm’s monitoring performance on small-scale severe cerebrovascular diseases. For patients with severe cerebrovascular disease in general, APACHEII1, APACHEII2, APACHEII3 and the trend of APACHEII score change are divided into high-risk group and low-risk group. The overall severe cerebrovascular disease, severe cerebral hemorrhage and severe cerebral infarction are analyzed, respectively. The differences are statistically significant.

Pre-procedural color duplex ultrasound evaluation predicts restenosis after long-segment superficial femoral artery stenting

OBJECTIVES

Restenosis after stenting for superficial femoral artery atherosclerotic disease remains a significant clinical problem, especially for long-segment lesions. We assessed predictors of in-stent restenosis in patients with long-segment superficial femoral artery disease and hypothesized that pre-procedural ultrasound assessment would predict in-stent restenosis.

METHODS

This single-center study retrospectively analyzed 283 limbs in 243 patients who treated with superficial femoral artery nitinol stent placement for long-segment (≥15 cm) lesions between 2015 and 2018. Color duplex ultrasound was performed pre-procedure and post-procedure at 3, 6, 12, 24, and 36 months. The endpoint was ≥50% in-stent restenosis in the superficial femoral artery. Primary patency rates were analyzed with Kaplan-Meier survival analysis and compared using the log-rank test. A multivariable Cox proportional hazards model was used to evaluate the risk factors for in-stent restenosis.

RESULTS

The median length of lesions was 25.8 ± 8.1 cm. The cumulative freedom from ≥50% in-stent restenosis at 3, 6, 12, 24, and 36 months was 95.3%, 78.3%, 56.0%, 30.6%, and 15.9%, respectively. Univariate and multivariate Cox regression analysis showed that cumulative lesion length ≥ 25 cm (hazard ratio 1.681; p = 0.003), calcified plaque (hazard ratio 1.549, p = 0.006), poor runoff scores >10 (hazard ratio 1.870, p = 0.003), and chronic renal failure (hazard ratio 2.075, p = 0.009) were independent risk factors for in-stent restenosis. The agreement rate between ultrasound and angiography was 92.6% for cumulative lesion length (κ 0.851) and 91.9% for runoff score (κ 0.872).

CONCLUSIONS

The results indicate that pre-procedural color duplex ultrasound evaluation is helpful for the selection of appropriate candidates for superficial femoral artery stent placement. Cumulative lesion length ≥25 cm, plaque calcification, poor distal runoff, and chronic renal failure independently predicted in-stent restenosis.