Comparison of the prevalence of asymptomatic carotid atherosclerosis detected by high-resolution ultrasonography in rural and urban middle-aged Japanese men

Using eZIS of SPECT to evaluate the therapeutic effect of carotid endarterectomy

OBJECTIVE

Stroke is an acute cerebrovascular disease with high morbidity and mortality. The main causes of ischemic stroke include carotid artery stenosis, and carotid endarterectomy (CEA) can be used to improve the blood flow of the lesion site. Regional cerebral blood flow (rCBF) can be decreased by using single photon emission computed tomography (SPECT). The Easy Z-Score imaging system (eZIS) can display the changes of rCBF as Z-Score. The purpose of this study was to determine whether eZIS of SPECT can be used to evaluate the therapeutic effect of CEA in the treatment of carotid artery stenosis.

METHODS

In this study, subjects were divided into the surgery group and the control group. The surgery group included seven patients with unilateral or bilateral internal carotid artery stenosis who received CEA treatment, and the control group included 11 patients who only received conventional drug treatment but did not receive surgery. Cerebral perfusion imaging (CPI) was collected twice before and after the corresponding treatment (within 6 months). rCBF of the lesion site was measured and Z-score was calculated before and after treatment by the eZIS technique.

RESULTS

The postoperative Z-score of the surgery group was 0.54 ± 2.71 compared with that of the preoperative -1.34 ± 2.68 ( P  = 0.0034; t  = 4.687; df  = 6), while the z-score of the control group was -0.33 ± 2.58 compared with that of the pretreatment 1.84 ± 2.62 ( P  = 0.0010; t  = 4.618; df  = 10).

CONCLUSION

CEA can effectively improve the blood flow in the lesion area of patients with carotid artery stenosis. eZIS of SPECT can be used to evaluate the therapeutic effect of CEA on carotid artery stenosis visually.

Carotid Ultrasound Screening Programs in Rural Communities: A Systematic Review

Carotid atherosclerosis assessments inform about stroke and cardiovascular risk. It is known that stroke and cardiovascular disease (CVD) prevalence is higher in rural communities than in urban communities. We aimed to conduct a systematic review of rural carotid ultrasound screening programs to define carotid atherosclerosis using traditional and emerging imaging biomarkers, prevalence, and risk factors. We searched Ovid/MEDLINE, Ovid/EMBASE, SCOPUS and CINAHL from inception to 3 April 2020 for rural population studies that utilized carotid ultrasound screening for adults ≥40 years of age and free of known cerebrovascular disease. Studies were included if participants received a bilateral ultrasound scanning of the carotid arteries and reported at least one marker of carotid atherosclerosis pathology. A random effect meta-analyses calculated the estimated prevalence of carotid plaque. In total, 22/3461 articles that met all of the inclusion criteria were included. Studies reported increased intima media thickness (IMT), carotid plaque presence and carotid artery stenosis. There were no studies reporting on novel imaging markers, such as carotid stiffness, carotid plaque morphology or neovascularization. The overall random effect pooled prevalence of carotid plaque was 34.1% (95% CI, 33.6–35.0); the prevalence of increased IMT was 11.2–41.5%, and the prevalence of carotid artery stenosis was 0.4–16.0%. There is an absence of data necessary to understand the carotid atherosclerosis prevalence across global rural populations. Represented studies have focused on East Asian countries where a high burden of rural carotid artery disease has been reported. There is no rural evidence to guide the use of novel ultrasound carotid biomarkers such as stiffness or neovascularization.

Medical and Revascularization Therapies for Asymptomatic Carotid Stenosis

Asymptomatic internal carotid artery stenosis increases with age and is more common in men. Carotid endarterectomy and stenting have reduced stroke rates in patients with asymptomatic carotid stenosis in clinical trials. A variety of risk stratification methods are available for selection of patients with carotid stenosis for revascularization. In the past decade, there is increasing evidence that the rate of stroke declined with the use of aggressive multi-modal medical therapy. These developments have led to new clinical trials to compare revascularization versus aggressive medical therapy in patients with asymptomatic carotid stenosis.

Prevalence of asymptomatic carotid artery stenosis according to age and sex: systematic review and metaregression analysis

BACKGROUND AND PURPOSE

In the discussion on the value of population-wide screening for asymptomatic carotid artery stenosis (ACAS), reliable prevalence estimates are crucial. We set out to provide reliable age- and sex-specific prevalence estimates of ACAS through a systematic literature review and meta-regression analysis.

METHODS

We searched PubMed and EmBase until December 2007 for studies that reported the prevalence of ACAS in a population free of symptomatic carotid artery disease. Data were extracted with use of a standardized form on participants' characteristics, assessment method, study quality, and prevalence estimates for moderate (>or=50% stenosis) and severe (>or=70% stenosis) ACAS. Metaregression was used to investigate sources of heterogeneity.

RESULTS

Forty studies fulfilled the inclusion criteria. There was considerable variation among studies with respect to demographics, methods of grading stenosis, and stenosis cutoff point used. The pooled prevalence of moderate stenosis was 4.2% (95% CI, 3.1% to 5.7%). Prevalence of moderate stenosis among people age <70 years was 4.8% (95% CI, 3.1% to 7.3%) in men and 2.2% (95% CI, 0.9% to 4.9%) in women. Among those >or=70 years, prevalence increased to 12.5% (95% CI, 7.4% to 20.3%) in men and to 6.9% (95% CI, 4.0% to 11.5%) in women. Metaregression showed that both age and sex significantly affected the prevalence of moderate stenosis. No contribution of study size, publication year, geographic region, assessment method, and study quality was found. The pooled prevalence of severe stenosis was 1.7% (95% CI, 0.7% to 3.9%).

CONCLUSIONS

Prevalence of moderate stenosis increases with age in both men and women, but men at all ages have the higher prevalence estimates. The number of studies that allowed meaningful data synthesis of severe stenosis was limited.