Vertebrobasilar Flow Evaluation and Risk of Transient Ischemic Attack and Stroke

描述(申请人提供)：在每年遭受的70万中风中，超过三分之一发生在后循环，其主要原因是动脉粥样硬化性椎基底动脉闭塞症。有症状的椎基底动脉疾病每年中风的风险很高，平均每年有10%-15%。血管内成形术和支架置入术的进展创造了新的治疗选择，但这些干预措施具有很大的风险，确定合适候选者的选择标准仍然不确定。在开始昂贵的大规模干预随机试验之前，有必要确定最有可能从治疗中受益的适当高危人群。这项研究的总体目标是确定椎基底动脉疾病患者中中风复发风险最高的人群。这一结果将为未来血管内或外科干预的临床试验奠定良好的基础。初步的回顾数据表明，椎基底动脉疾病的卒中风险与颅内血流受损密切相关，其程度可通过定量磁共振血管成像(QMRA)无创测量。目的是对有症状的椎基底动脉狭窄(50%)或闭塞的患者进行前瞻性的多中心观察研究，以验证那些表现出血流障碍的患者中风风险较高的假设。登记后，受试者将接受QMRA的血流动力学评估，以评估椎基底动脉区域的大血管血流，并接受MR灌注评估组织水平的血流灌注。根据现有的初步数据，受试者将被前瞻性地指定为表现为脑血流受损或正常；结果将对医生和患者保密。将系统地收集基线临床、实验室和流行病学数据。对于椎基底动脉区域的主要卒中终点，患者将每月接受至少12个月的随访。公共卫生相关性：通过确定中风复发风险最高的人群，这项研究将对旨在评估椎基底动脉疾病治疗干预措施的未来临床试验的选择标准和成功可能性产生重大影响。此外，从公共健康和医疗保健成本的角度来看，能够确定不需要昂贵的侵入性干预风险的低风险人群将产生同样重要的影响。

DESCRIPTION (provided by applicant): Over one third of the 700,000 strokes suffered annually occur in the posterior circulation, a major cause of which is atherosclerotic vertebrobasilar occlusive disease. Symptomatic vertebrobasilar disease carries a high annual stroke risk, averaging 10-15% per year. Advances in endovascular angioplasty and stenting have created new treatment options, but these interventions carry significant risks, and selection criteria for determining appropriate candidates remain uncertain. Prior to embarking on expensive large-scale randomized trials of intervention, it is necessary to define the appropriate high risk population most likely to benefit from treatment. The overall goal of this study is to define the population of patients with vertebrobasilar disease at highest risk of recurrent stroke. The results will be well poised to form the basis for future clinical trials of endovascular or surgical interventions. Preliminary retrospective data indicates that stroke risk in vertebrobasilar disease is strongly related to compromised intracranial blood flow, the extent of which can be measured noninvasively using quantitative magnetic resonance angiography (QMRA). The objective is to conduct a prospective multi-center observational study of patients with symptomatic angiographically confirmed vertebrobasilar stenosis (e 50%) or occlusion to test the hypothesis that those who demonstrate compromised blood flow are at higher stroke risk. Upon enrollment, subjects will undergo hemodynamic assessment with QMRA to assess large vessel flow, and MR perfusion to assess tissue level perfusion, in the vertebrobasilar territory. Subjects will be prospectively designated as demonstrating compromised or normal cerebral flow, based upon existing preliminary data; the results will be kept blinded from treating physicians and patients. Baseline clinical, laboratory, and epidemiological data will be systematically collected. Patients will be followed at monthly intervals for a minimum of 12 months for the primary endpoint of stroke in the vertebrobasilar territory. PUBLIC HEALTH RELEVANCE: By defining the population of patients at highest risk of recurrent stroke, this study will significantly impact the selection criteria and likelihood for success of future clinical trials aimed at assessing interventions for the treatment of vertebrobasilar disease. Additionally, the ability to define a low risk population in whom the risks of expensive invasive interventions would be unnecessary will have an equally important impact from a public health, and health care cost, perspective.