Jones, Michael

Background and Purpose: The CREST-2 (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial) consists of 2 parallel randomized stroke prevention trials in patients with asymptomatic high-grade stenosis of the cervical carotid artery. The purpose of this report is to detail the outcomes of a health screening effort to increase trial enrollment of women and minorities. Methods: Life Line screening (LLS) conducts nationwide screening for vascular disease. Screenings within a 50-mile radius of each CREST-2 center were identified for participation in a joint CREST-LLS program over the course of one year (November 2018 to October 2019) whereby patients with an abnormal carotid ultrasound were referred to the local CREST-2 center for further workup, management, and potential consideration for trial enrollment. Results: LLS completed the screening of 588 198 individuals in 29 732 zip codes across the United States. Of those, 230 021 individuals were screened at events occurring near a CREST-2 clinical center and 646 (0.3%) were found to have abnormal carotid ultrasound findings. Each of the 646 individuals was contacted by CREST-LLS program staff for permission to be referred to their local CREST-2 center; 200 (31%) consented to be contacted by CREST-2. Of those, 39 (19.5%) agreed to be, and were, evaluated at their local CREST-2 center. High-grade stenosis was confirmed in 27 patients. A total of 3 patients were eligible for the trial and were enrolled, one woman but no racial/ethnic minorities. Conclusions: The LLS program appears to identify community-living individuals with high-grade carotid stenosis through ultrasonography. However, the prevalence of abnormal carotid findings was low. In addition, screening and offering participation into the CREST-2 trial had no substantial impact on the proportion of women and minorities enrolled in the trial. Additional innovative strategies are needed to promote enrollment of diverse patients with carotid stenosis into stroke prevention trials.

Background and Purpose: Despite a higher incidence of stroke and a more adverse cardiovascular risk factor profile in Blacks and Hispanics compared with Whites, carotid artery revascularization is performed less frequently among these subpopulations. We assessed racial differences in high-grade (≥70% diameter-reducing) carotid stenosis. Methods: Consecutive clients in a Nationwide Life Line for-Profit Service to screen for vascular disease, 2005 to 2019 were evaluated in a cross-sectional study. The prevalence of high-grade stenosis, defined by a carotid ultrasound peak systolic velocity of ≥230 cm/s, was assessed. Participants self-identified as White, Black, Hispanic, Asian, Native American, or other. Race/ethnic differences were assessed using Poisson regression. The number of individuals in the United States with high-grade stenosis was estimated by applying prevalence estimates to 2015 US Census population estimates. Results: The prevalence of high-grade carotid stenosis was estimated in 6 130 481 individuals. The prevalence of high-grade stenosis was higher with increasing age in all race-sex strata. Generally, Blacks and Hispanics had a lower prevalence of high-grade stenosis compared with Whites, while Native Americans had a higher prevalence. For example, for men aged 55 to 65, the relative risk of stenosis compared with Whites was 0.40 (95% CI, 0.29–0.55) and 0.61 (95% CI, 0.46–0.81) for Blacks and Hispanics, respectively; and 1.53 (95% CI, 1.12–2.10) for Native Americans. When these prevalence estimates were applied to the Census estimates of the US population, an estimated 327 721 individuals have high-grade stenosis, of whom 7% are Black, 7% Hispanic, and 43% women. Conclusions: Despite their having a more adverse cardiovascular risk profile, there was a lower prevalence of high-grade carotid artery stenosis for both the Black and Hispanic relative to the White clients. This lower prevalence of high-grade stenosis is a potential contributor to the lower use of carotid revascularization procedures in these minority populations.

Objectives: Assessment of carotid disease is most commonly performed with duplex ultrasonography (DUS). Measures of plaque area and tissue composition from DUS images may identify patients at risk for future neurologic events, and may assess the effects of vascular risk-factor modification (by measuring change in plaque area and/or tissue constituents). We quantified plaque area and tissue constituents from DUS images of CREST-2 participants at baseline and correlated them with their baseline vascular risk factors. Methods: CREST-2 consists of two multicenter, randomized trials in patients with asymptomatic ≥70% carotid stenosis comparing intensive medical management (IMM) plus endarterectomy or stenting vs IMM alone. Baseline B-mode DUS images from 500 patients underwent manual plaque outlining and automatic pixel brightness assessment. Plaque area, grayscale median (GSM), Gray-Weale score for heterogeneity, and areas for intraplaque hemorrhage and lipid were the output parameters. We computed the parameter estimates (95% confidence intervals) for baseline patient characteristics (age, sex, race, diabetes, smoking, BMI, blood pressure and LDL levels) versus plaque characteristics. Results: High-risk plaque features (larger plaque area, lower GSM , lower Gray-Weale scores, or larger areas of hemorrhage and lipid) were present in older patients, males, and those with elevated diastolic blood pressure and LDL levels (Table). Conclusions: In a randomized trial of asymptomatic patients with high-grade carotid stenosis, DUS-based computation of plaque geometry and tissue composition is feasible. Elevated diastolic blood pressure and LDL levels at baseline are associated with high-risk plaque characteristics. These novel findings identify potentially modifiable targets for aggressive treatment to reduce stroke-risk in patients with carotid stenosis.