Characterizing Hemodynamic Compensation in Patients With Intracranial Stenosis

NCT02506907 | Completed

• 1 other identifier: VUMC-VAMMPRIS
• Study Type: observational
• Target: 63
• Locations: 1 country
• Sites: 1

Brief Summary

The overall aim of this work is to assess the relationship between stroke risk and hemodynamic compensation strategies, as measured using a novel 3.0 Tesla MRI protocol, in patients with symptomatic intracranial (IC) steno-occlusive disease. Recent studies have shown high two-year ischemic stroke rates in symptomatic patients with IC arterial stenosis. Therapy for IC stenosis patients includes revascularization with angioplasty, IC stenting, or bypass, however identification of patients most likely to benefit from these more aggressive interventions, rather than medical management alone, has been problematic. Accurate measurements of hemodynamic compromise are likely required to better define stroke risk and guide treatment decisions. Specifically, in IC stenosis patients with compromised cerebral perfusion pressure (CPP), the extent of hemodynamic compromise reflects the autoregulatory capacity of vasculature to increase arterial cerebral blood volume (aCBV) and/or develop collaterals to supplement cerebral blood flow (CBF). The prevalence of CBF collateralization and aCBV autoregulation has been hypothesized to correlate uniquely with stroke risk, however the extent of this correlation has been debated. The critical barrier to stratifying stroke risk rests with a lack of (i) methodology for measuring multiple hemodynamic factors with high specificity and (ii) noninvasive approaches capable of monitoring longitudinal progression of impairment. The investigators have demonstrated the clinical utility of relatively new, noninvasive MRI approaches for assessing cerebrovascular reactivity (CVR), aCBV, and collateral CBF. The investigators hypothesize that stroke risk can be more completely evinced from collective measurements of these parameters. Therefore, the investigators propose to implement a novel, validated hemodynamic MRI protocol to assess tissue-level impairment and compensation strategies in patients with IC stenosis. Using a collective approach combining measurements of collateral CBF, aCBV and CVR in multiple brain regions, in conjunction with a statistical model incorporating the above variables as possible prognostic factors, the investigators will quantify the extent to which two-year stroke risk is associated with hemodynamic compensation mechanisms. The noninvasive and multi-faceted scope of this investigation is intended to expand the diagnostic stroke infrastructure and elucidate new hemodynamic prognostic indicators of stroke in this high-risk population.

Conditions

Stroke; Intracranial Stenosis

Outcome Measures

Primary Outcomes (1)

• Stroke

  An overt or silent stroke (on MRI) in two years

  Two years

Study Arms (1)

Atherosclerotic

Patients with atherosclerotic intracranial stenosis

Eligibility Criteria

• Age: 18 Years - 85 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patients with intracranial stenosis who have had a stroke within the past 60 days

You may qualify if:

• Adult patients (age 18-85, inclusive)
• Symptomatic (TIA or ischemic stroke) in the hemispheric carotid territory of vascular stenosis
• Vascular imaging demonstrating large vessel IC stenosis\>50% or occlusion of IC carotid or MCA
• Sub-acute stroke patients who have received intravenous or intra-arterial treatments
• Sub-acute stroke patients ineligible for conventional acute stroke intervention. Language comprehension intact, motor aphasia mild or absent, competent to give informed consent
• Most recent qualifying TIA or stroke within 60 days prior to performance date of hemodynamic MRI

You may not qualify if:

• ECA stenosis \> 70% determined by MRA, CTA, or DSA.
• Acute stroke patients presenting with anterior circulation stroke onset eligible for intervention with intra-arterial thrombolysis or mechanical thrombectomy
• MRI contraindications (e.g. non-compatible implants, pregnancy, etc.)
• Non-atherosclerotic cervical or intracranial stenosis
• Heart disease likely to cause cerebral ischemia, including cardiomyopathy with ejection fraction\<25%, prosthetic valve, infective endocarditis, sick sinus syndrome, myxoma, left atrial or ventricular thrombus
• Existing condition likely to lead to death within 2 years

Sponsors & Collaborators

• Vanderbilt University: lead

Study Sites (1)

Vanderbilt University Medical Center

Nashville, Tennessee, 37232, United States

Location

MeSH Terms

Conditions

Stroke

Condition Hierarchy (Ancestors)

Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor of Radiology

Study Record Dates

• First Submitted: July 21, 2015
• First Posted: July 23, 2015
• Study Start: August 1, 2012
• Primary Completion: June 6, 2016
• Study Completion: November 1, 2017
• Last Updated: January 25, 2018

Record last verified: 2018-01

Locations

US (1)