ABSTRACT
BACKGROUND: Intracranial atherosclerotic disease (ICAD) is the most frequent subtype of ischemic stroke globally. It is important to describe the determinants of early ICAD as a strategy to prevent strokes from clinically evident and progressive ICAD. Our objective is to report the determinants of asymptomatic ICAD by linking the presence or absence of ICAD on magnetic resonance angiogram (MRA) with detailed risk assessment in asymptomatic adults. METHODS: This is an observational cross-sectional analytical study. We plan to recruit 200 adult participants from the radiology departments of two tertiary care centers of Karachi, Pakistan. The participants will first be screened for the absence of stroke symptoms via the Questionnaire for Verifying Stroke Free Status (QVSFS). QVSFS negative will be participants will be eligible. After written informed consent, participants will undergo detailed medical, sociodemographic, lifestyle, and anthropometric evaluation by a detailed interview. They will, in addition, undergo MRA to study the presence, degree, and distribution of asymptomatic ICAD. All MRA scans will be reviewed centrally by vascular neurologists blinded to clinical information. These images would be reviewed on DICOM Viewer 3.0 used for calculating the degree of stenosis using Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) study defined criteria employing electronic calipers. A sample size of 200 will achieve 80% power for detecting a minimum difference of 20% in the prevalence of exposure factors (medical and lifestyle) between asymptomatic ICAD positive and ICAD negative persons. This study will generate regional data on risks for ICAD development and prevention in a high-risk susceptible population. Study ID: NCT02072876.
ABSTRACT
BACKGROUND: Intracranial Atherosclerotic Disease (ICAD) is the most frequent etiology of stroke with high prevalence among Asians. Despite this, early determinants of ICAD have not been described from this region. METHODS: The study is an analytical prospective cross-sectional study of 200 adults from Radiology Departments of two diagnostic centers in Karachi. Eligible participants confirmed the absence of stroke symptoms via the Questionnaire for Verifying Stroke Free Status (QVSFS) and underwent an interview covering medical, socio demographic, lifestyle and anthropometric evaluation using locally validated and standardized definitions. Magnetic Resonance Images (MRI) were centrally reviewed to detect ICAD using the criterion used in the Warfarin-Aspirin Symptomatic Intracranial Disease study. The risk factors associated with asymptomatic ICAD are reported along with prevalence ratios. RESULTS: Of the 200 participants, ICAD was found in 34.5% (n = 69) of the participants. Mean age was 37.1 (S.D 15.1) years with 62% younger than 45 years. Self-reported hypertension was found in 26.5% subjects, diabetes in 9%, dyslipidemia in 5% and depression in 60%. Smokeless tobacco (Adjusted PR 3.27 (1.07-6.05)), Western diet, high socioeconomic status (Adjusted PR 2.26 (1.99-5.62)) and dyslipidemia (Adjusted PR 1.88 (1.25-2.21)) had significant associations with ICAD after multivariable analysis. Age, gender, diabetes, hypertension, depression and physical activity did not have a significant association. CONCLUSION: ICAD was found on MRI in one in three asymptomatic Pakistanis and was associated with modifiable risks. Initiatives targeting primary prevention may be able to decrease the burden of disease caused by stroke due to ICAD. STUDY REGISTRATION NUMBER: NCT02072876 2/25/2014.
