Barrett, Kevin M.

Introduction: Abdominal aortic aneurysm (AAA) rupture has a mortality rate of 64% and intracranial aneurysm (IA) rupture has a mortality rate of 50%. Despite the high mortality rates, early detection and treatment of these vascular lesions prior to rupture can prevent devastating clinical outcomes, underscoring the need to identify high-risk populations for screening. Current evidence demonstrates shared genetic and environmental risk factors for both AAA and IA. Methods: The BAAS study sought to establish the co-prevalence of AAA and IA. In one arm of BAAS, we recruited patients presenting with AAA and screened them for IA. All participants underwent a detailed interview to collect demographic, radiographic, and clinical data and also had genetic counseling. Results: Of the 126 individuals with an AAA enrolled, 65% (82/126) completed the MRA. Difficulty with logistics of obtaining the research MRA with long distance travel to clinic was the principal reason for failure to obtain MRA. We identified 20.7% (17/82) with one or more IA, including 21 aneurysms found during systematic screening. IA ranged in size from 1.5-14 mm (height) x 1.4-7 mm (width) and varied in location. 9.5% (2/21) had a maximum diameter of 7 mm or more. One participant with a positive MRA underwent early coil embolization with the remainder undergoing continued clinical surveillance. Of the 15 individuals completing the genetic counseling screening, two underwent recommended clinical genetic testing, revealing one negative screen and one variant of unknown significance in the MYH11 gene. Conclusion: Consistent with our prior cost effectiveness models, these prospective data support the clinical utility of routine screening for IA in patients presenting with AAA.

Background and Purpose— Multicenter clinical trials attempt to select sites that can move rapidly to randomization and enroll sufficient numbers of patients. However, there are few assessments of the success of site selection. Methods— In the CREST-2 (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trials), we assess factors associated with the time between site selection and authorization to randomize, the time between authorization to randomize and the first randomization, and the average number of randomizations per site per month. Potential factors included characteristics of the site, specialty of the principal investigator, and site type. Results— For 147 sites, the median time between site selection to authorization to randomize was 9.9 months (interquartile range, 7.7, 12.4), and factors associated with early site activation were not identified. The median time between authorization to randomize and a randomization was 4.6 months (interquartile range, 2.6, 10.5). Sites with authorization to randomize in only the carotid endarterectomy study were slower to randomize, and other factors examined were not significantly associated with time-to-randomization. The recruitment rate was 0.26 (95% confidence interval, 0.23–0.28) patients per site per month. By univariate analysis, factors associated with faster recruitment were authorization to randomize in both trials, principal investigator specialties of interventional radiology and cardiology, pre-trial reported performance >50 carotid angioplasty and stenting procedures per year, status in the top half of recruitment in the CREST trial, and classification as a private health facility. Participation in StrokeNet was associated with slower recruitment as compared with the non-StrokeNet sites. Conclusions— Overall, selection of sites with high enrollment rates will likely require customization to align the sites selected to the factor under study in the trial. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT02089217.

Rationale Trials conducted decades ago demonstrated that carotid endarterectomy by skilled surgeons reduced stroke risk in asymptomatic patients. Developments in carotid stenting and improvements in medical prevention of stroke caused by atherothrombotic disease challenge understanding of the benefits of revascularization. Aim Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial (CREST-2) will test whether carotid endarterectomy or carotid stenting plus contemporary intensive medical therapy is superior to intensive medical therapy alone in the primary prevention of stroke in patients with high-grade asymptomatic carotid stenosis. Methods and design CREST-2 is two multicenter randomized trials of revascularization plus intensive medical therapy versus intensive medical therapy alone. One trial randomizes patients to carotid endarterectomy plus intensive medical therapy versus intensive medical therapy alone; the other, to carotid stenting plus intensive medical therapy versus intensive medical therapy alone. The risk factor targets of centrally directed intensive medical therapy are LDL cholesterol <70 mg/dl and systolic blood pressure <140 mmHg. Study outcomes The primary outcome is the composite of stroke and death within 44 days following randomization and stroke ipsilateral to the target vessel thereafter, up to four years. Change in cognition and differences in major and minor stroke are secondary outcomes. Sample size Enrollment of 1240 patients in each trial provides 85% power to detect a treatment difference if the event rate in the intensive medical therapy alone arm is 4.8% higher or 2.8% lower than an anticipated 3.6% rate in the revascularization arm. Discussion Management of asymptomatic carotid stenosis requires contemporary randomized trials to address whether carotid endarterectomy or carotid stenting plus intensive medical therapy is superior in preventing stroke beyond intensive medical therapy alone. Whether carotid endarterectomy or carotid stenting has favorable effects on cognition will also be tested. Trial registration United States National Institutes of Health Clinicaltrials.gov NCT02089217

Extracranial internal carotid artery atherosclerotic occlusive disease is a common ischemic stroke mechanism. Vascular risk factor control remains the cornerstone of stroke prevention in patients with both asymptomatic and symptomatic carotid occlusive diseases. Intensive medical therapy refers to the contemporary approach of antiplatelet therapy, blood pressure control, low-density lipoprotein reduction, and lifestyle modification to reduce stroke risk. Carotid revascularization with endarterectomy or angioplasty and stenting are established treatments for patients with symptomatic carotid stenosis ≥70%. Previously accepted ischemic stroke preventative strategies, such as carotid revascularization for asymptomatic carotid stenosis, require reassessment given advances in both medical therapy and surgical techniques. The purpose of this review is to describe contemporary approaches to the management of extracranial carotid atherosclerotic occlusive disease and the basis of these recommendations. Results from recently published clinical trials will be highlighted in addition to updated information from clinical trials addressing knowledge gaps in prevention of stroke caused by extracranial disease.

Background Ischemic stroke is a time-sensitive disease, with improved outcomes associated with decreased time from onset to treatment. It was hypothesised that ambulance-based assessment of the National Institutes of Health Stroke Scale (NIHSS) using a Health Insurance Portability and Accountability Act (HIPAA)–compliant mobile platform immediately prior to arrival is feasible. Methods This is a proof-of-concept feasibility pilot study in two phases. The first phase consisted of an ambulance-equipped HIPAA-compliant video platform for remote NIHSS assessment of a simulated stroke patient. The second phase consisted of remote NIHSS assessment by a hospital-based neurologist of acute stroke patients en route to our facility. Five ambulances were equipped with a 4G/LTE-enabled tablet preloaded with a secure HIPAA-compliant telemedicine application. Secondary outcomes assessed satisfaction of staff with the remote platform. Results Phase one was successful in the assessment of three out of three simulated patients. Phase two was successful in the assessment of 10 out of 11 (91%) cases. One video attempt was unsuccessful because local LTE was turned off on the device. The video signal was dropped transiently due to weather, which delayed NIHSS assessment in one case. Average NIHSS assessment time was 7.6 minutes (range 3–9.8 minutes). Neurologists rated 83% of encounters as ‘satisfied’ to ‘very satisfied’, and the emergency medical service (EMS) rated 90% of encounters as ‘satisfied’ to ‘very satisfied’. The one failed video attempt was associated with ‘poor’ EMS satisfaction. Conclusion This proof-of-concept pilot demonstrates that remote ambulance-based NIHSS assessment is feasible. This model could reduce door-to-needle times by conducting prehospital data collection.

Wake-up stroke, defined as the situation where a patient awakens with stroke symptoms that were not present prior to falling asleep, represents roughly 1 in 5 acute ischemic strokes and remains a therapeutic dilemma. Patients with wake-up stroke were excluded from most ischemic stroke treatment trials and are often not eligible for acute reperfusion therapy in clinical practice, leading to poor outcomes. Studies of neuroimaging with standard noncontrast computed tomography (CT), magnetic resonance imaging (MRI), and multimodal perfusion-based CT and MRI suggest wake-up stroke may occur shortly before awakening and may assist in selecting patients for acute reperfusion therapies. Pilot studies of wake-up stroke treatment based on these neuroimaging features are promising but have limited generalizability. Ongoing randomized treatment trials using neuroimaging-based patient selection may identify a subset of patients with wake-up stroke that can safely benefit from acute reperfusion therapies.