Intracranial arterial stenosis in Ecuadorian Natives/Mestizos. A population-based study in older adults (The Atahualpa Project)

High prevalence of intracranial arterial stenosis among acute ischemic stroke patients in a Brazilian center: a transcranial color-coded duplex sonography study

BACKGROUND

 There is limited data available regarding the prevalence of intracranial arterial stenosis (ICAS) among acute ischemic stroke (AIS) patients in Brazil and Latin America.

OBJECTIVE

 The present study sought to investigate the frequency and predictors of ICAS among patients with AIS or transient ischemic attack (TIA) in a Brazilian center, with transcranial color-coded duplex sonography (TCCS) technique.

METHODS

 Consecutive AIS and TIA patients, admitted to an academic public comprehensive stroke center in Brazil from February to December 2014, evaluated by TCCS were prospectively selected. Vascular narrowings > 50% were considered as ICAS, based on ultrasound criteria previously defined in the literature.

RESULTS

 We assessed 170 consecutive patients with AIS or TIA, of whom 27 (15.9%) were excluded due to an inadequate transtemporal acoustic bone window. We confirmed ICAS in 55 patients (38.5%). The most common location was the proximal segment of the middle cerebral artery (28.2%), followed by the vertebral (15.4%), posterior cerebral (13.6%), terminal internal carotid (9.1%) and basilar (8.2%) arteries. On multivariate models adjusting for potential confounders, systolic blood pressure (OR: 1.03, 95%CI: 1.01-1.04; p = 0.008) was independently associated with ICAS.

CONCLUSION

 We found significant ICAS in approximately ⅓ of patients admitted with symptoms of AIS or TIA in a public tertiary academic stroke center in Brazil. The TCCS is an accessible and noninvasive technique that can be used to investigate the presence of moderate and severe ICAS, especially in patients who cannot be exposed to more invasive exams, such as the use of intravenous contrast agents.

Prevalence of intracranial artery stenosis in a general population using 3D-time of flight magnetic resonance angiography

BACKGROUND

Data on prevalence of intracranial artery stenosis (ICAS) in Western populations is sparse. The aim of the study was to assess the prevalence and risk factors for ICAS in a mainly Caucasian general population.

METHODS

We assessed the prevalence of ICAS in 1847 men and women aged 40 to 84 years who participated in a cross-sectional population-based study, using 3-dimensional time-of-flight 3 Tesla magnetic resonance angiography. ICAS was defined as a focal luminal flow diameter reduction of ≥50 %. The association between cardiovascular risk factor levels and ICAS was assessed by multivariable regression analysis.

RESULTS

The overall prevalence of ICAS was 6.0 % (95 % confidence interval (CI) 5.0-7.2), 4.3 % (95 % CI 3.1-5.7) in women and 8.0 % (95 % CI 6.3-10.0) in men. The prevalence increased by age from 0.8 % in 40-54 years age group to 15.2 % in the 75-84 years age group. The majority of stenoses was located to the internal carotid artery (52.2 %), followed by the posterior circulation (33.1 %), the middle cerebral artery (10.8 %) and the anterior cerebral artery (3.8 %). The risk of ICAS was independently associated with higher age, male sex, hypertension, hyperlipidemia, diabetes mellitus, current smoking and higher BMI.

CONCLUSIONS

The prevalence of ICAS in a general population of Caucasians was relatively high and similar to the prevalence of extracranial internal carotid artery stenosis in previous population-based studies.

Prevalence and Correlates of Intracranial Atherosclerotic Disease Among Community-Dwelling Older Adults of Amerindian Ancestry. The Three Villages Study

BACKGROUND

Knowledge on the prevalence and correlates of intracranial atherosclerotic disease (ICAD) is limited. We aimed to assess prevalence, clinical and neuroimaging correlates of ICAD in a cohort of older adults of Amerindian ancestry.

METHODS

The study included 581 community-dwellers aged ≥60 years (mean age 71 ± 8.4 years; 57% women) living in rural Ecuadorian villages. ICAD was identified by means of CT determinations of carotid siphon calcifications (CSC) or MRA findings of significant stenosis of intracranial arteries. Fully-adjusted logistic regression models were fitted with biomarkers of ICAD as the dependent variables.

RESULTS

A total of 205 (35%) of 581 participants had ICAD, including 185 with high calcium content in the carotid siphons and 40 with significant stenosis of at least one intracranial artery (20 subjects had both biomarkers). Increasing age, high fasting blood glucose, >10 enlarged basal ganglia-perivascular spaces and non-lacunar strokes were associated with high calcium content in the carotid siphons. In contrast, male gender, moderate-to-severe white matter hyperintensities, lacunar and non-lacunar strokes were associated with significant stenosis of intracranial arteries. Stroke was more common among subjects with any biomarker of ICAD than in those with no biomarkers (29% versus 9%, p < 0.001). Significant stenosis of intracranial arteries was more often associated with stroke than high calcium content in the carotid siphons, suggesting that CSC are more likely an ICAD biomarker than causally related to stroke.

CONCLUSIONS

ICAD prevalence in Amerindians is high, and is significantly associated with stroke. CSC and significant stenosis of intracranial arteries may represent different phenotypes of ICAD.

Association of antinuclear antibodies with the risk of intracranial arterial stenosis

The prevalence of intracranial arterial stenosis (IAS) as well as antinuclear antibody (ANA) positivity was found to be higher in Asians than that in the Western population. To investigate the relation of ANAs with IAS in patients with acute ischemic cerebrovascular disease, we enrolled 2492 patients with acute ischemic stroke or transient ischemic attack into the study. All the patients were categorized into 3 groups according to the IAS burden. Multinomial logistic regression analyses were used in statistical analysis. The positive rate of ANAs in the IAS ≥ 2 group was higher than that in the single IAS group and the no IAS group (p<0.001). The adjusted odds ratio (OR) for IAS ≥ 2 in ANAs-positive patients was 3.737 (95%CI=2.676-5.220, p<0.001) compared with the ANAs-negative patients. ANAs were associated with multiple IAS rather than single IAS in both male and female subgroups. Besides, ANAs were significantly associated with single and multiple IAS in individuals ≤ 60 years. However, ANAs were only associated with two or more IAS in two age groups (between 61 to 75 years and >75 years old). In summary, ANAs are associated with IAS in patients with acute ischemic cerebrovascular disease.

Arterial Stiffness is Independently Associated with Severity of Carotid Siphon Calcifications in Community-Dwelling Older Adults: The Atahualpa Project

BACKGROUND

Knowledge on the association between arterial stiffness and intracranial atherosclerosis is limited. Here, we aimed to assess whether the aortic pulse wave velocity (PWV)-used as a surrogate of arterial stiffness-might independently predict severity of carotid siphon calcifications (CSCs), used as a marker of atherosclerosis.

METHODS

Of 437 Atahualpa residents aged 60 years or older, 300 (69%) underwent head computed tomography (CT) (for CSC assessment), brain magnetic resonance imaging (for identification of neuroimaging signatures of cerebral small vessel disease [SVD]), and aortic PWV determinations (for arterial stiffness estimation). Ordinal logistic regression models were constructed to predict severity of CSC (as the dependent variable) according to levels of aortic PWV after adjusting for demographics, cardiovascular risk factors, and neuroimaging signatures of SVD.

RESULTS

Grade 1 CSC were noticed in 120 (40%) subjects, grade 2 in 84 (28%), grade 3 in 73 (24%), and grade 4 in 23 (8%). The mean PWV was 10.4 ± 1.8 m/s, which increased from 9.8 ± 1.3 to 11.1 ± 2.1 m/s in individuals with grades 1 and 4 CSC, respectively (P <.001). The most parsimonious ordinal logistic regression model adjusted for relevant confounders showed a significant association between aortic PWV and severity of CSC. In this model, a change of 1 unit of aortic PWV increased the odds of CSC severity by 1.22 (95% confidence interval 1.07-1.39; P = .004).

CONCLUSIONS

The monotonically increased odds of aortic PWV among subjects with different grades of CSC, suggest that aortic PWV may be a marker for identifying candidates for CT screening in the search of CSC.

Hyperglycemia and dyslipidemia of Isabela, Galápagos, Ecuador: A pilot study of cardiovascular risk factors in an Isolated Island community

AIM

To evaluate the prevalence of hyperglycemia and dyslipidemia in the population of Isabela, Galápagos, Ecuador, across gender and age (above or below 50).

METHODS

In this population-based retrospective cross-sectional study among individuals in Isabela, Galápagos, Ecuador, demographic and metabolic factors were evaluated based on World Health Organization (WHO) Global Guidelines.

RESULTS

The population overall exceeded the WHO guidelines for cardiovascular health. As to be expected, there was significance in the trend of increasing dyslipidemia and hyperglycemia with age except postprandial glucose. In those individuals below the age of 50, 8.0%, 49% and 26% had hyperglycemia, hypercholesterolemia and hypertriglyceridemia, respectively. However, in those above 50, they measured 24%, 68% and 36% respectively, showing a significant increase.

CONCLUSIONS

Hyperglycemia and dyslipidemia appear to be prevalent in Isabela, Galápagos, Ecuador and this pilot study supports further research into metabolic syndrome and diabetes. Such data may help in healthcare planning and screening to ensure not only timely diagnosis, but prevention. The limitations of this data illustrate modalities that data collection can be improved, such as having a linked clinical history to the data itself and better patient follow up for such entities as post prandial glucose, for example. However, this pilot study presents a starting point for future directions of research, such as ascertaining prevalence of diabetes type II, metabolic syndrome and cardiovascular disease.