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Diffusion Weighted Imaging Evaluation for Understanding Stroke Evolution Study-2 (DEFUSE-2)

This study has been completed.
University of Pittsburgh
Northwestern University
University of Utah
Oregon Health and Science University
St. Luke's Medical Center
Queen's Medical Centre
Swedish Health Services
National Institute of Neurological Disorders and Stroke (NINDS)
Information provided by (Responsible Party):
Gregory W Albers, Stanford University Identifier:
First received: May 5, 2011
Last updated: April 12, 2016
Last verified: April 2016
Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution Study 2 (DEFUSE 2) is a multi-center pilot study to determine if cerebral perfusion imaging can help identify which patients, who are ineligible for intravenous tissue plasminogen activator (iv tPA) therapy or have failed iv tPA therapy, are most likely to benefit from an endovascular clot removal procedure.

Cerebrovascular Accident

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Prospective
Official Title: Diffusion Weighted Imaging Evaluation for Understanding Stroke Evolution Study-2 (DEFUSE-2)

Further study details as provided by Gregory W Albers, Stanford University:

Primary Outcome Measures:
  • NIHSS Score [ Time Frame: 30 days ]

Secondary Outcome Measures:
  • Modifies Rankin Score [ Time Frame: 90 days ]

Enrollment: 138
Study Start Date: June 2008
Study Completion Date: December 2011
Primary Completion Date: September 2011 (Final data collection date for primary outcome measure)
Detailed Description:

Currently, the only approved therapy for acute stroke patients is a medication called tissue plasminogen activator (tPA). This medication is given as an intravenous infusion and can dissolve blood clots, thereby restoring blood flow to the brain. Early restoration of blood flow can prevent the permanent damage to the brain which typically occurs after a stroke. As a result, patients who achieve early restoration of blood flow have less disability than stroke patients in whom blood flow is not restored. Unfortunately, only a very small fraction of stroke patients is treated with tPA and benefits from tPA. Nationwide only 3 percent of stroke patients receive this therapy. The short treatment time-window is one of the main reasons that patients are not eligible for this treatment. Previously, tPA was only recommended in the 0 - 3 hour time window after stroke onset, but recent studies have shown efficacy our to 4 ½ hours. AHA guidelines now recommend treatment with iv tPA up to 4 ½ hrs. However, the number of stroke patients who will benefit from treatment remains small despite expansion of the time-window from 3 to 4 ½ hrs. This is the result of two main limitations of tPA. First, the majority of stroke patients present beyond the 4 ½ hour time-window and will therefore remain ineligible for treatment. Second, stroke patients who receive tPA do not always benefit because the treatment does not restore blood flow in all patients. Our research has shown that depending on the location of the blood clot, blood flow is restored in only 20 to 50% of stroke patients treated with tPA.

Patients with persistent blood vessel occlusions and no improvement in their clinical condition after receiving tPA or those arriving at the hospital outside the 4 1/2 hour time window routinely undergo mechanical clot removal to open an occluded blood vessel in the brain.

Mechanical clot removal increases the percentage of stroke patients who achieve recanalization, and as a result may increase the proportion of patients who have good clinical outcomes. However it is unclear for which stroke patients mechanical thrombectomy is most suitable. Although effective at removing blood-clots, it appears that mechanical clot retrieval is not beneficial for all patients. Whereas some patients benefit, others experience no effect, and yet others are likely harmed by mechanical clot retrieval. In order to avoid harm and maximize benefit it is important to know, prior to initiation of the mechanical clot retrieval procedure, if the procedure is likely to result in a clinical improvement. The investigators hypothesize that the response to mechanical clot retrieval can be predicted based on characteristics of an MRI scan obtained just prior to the retrieval procedure. The investigators hope to learn if new MRI techniques can help identify which patients are most likely to benefit from mechanical clot removal after receiving tPA.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
population includes those people with acute ischemic stroke

Inclusion Criteria:

  1. Age 18 years and older
  2. Clinical diagnosis of ischemic stroke and a score of 5 or more points in the NIHSS.
  3. Planned to undergo intra-arterial (IA) therapy for acute hemispheric stroke (Either as primary therapy or as adjuvant therapy following intravenous tPA treatment)
  4. Planned to have a standard MRI including perfusion imaging and MR angiography of the circle of Willis (MRA) prior to IA therapy
  5. Intra-arterial thrombectomy can be started within 90 minutes of completion of MRI scan and within 12 hours of symptom onset. (Start of IA therapy is defined as the time of insertion of the femoral artery sheath; Time of brain scan is defined as the time that the scan is completed)
  6. Able to obtain informed consent (informed consent should be obtained prior to the baseline MRI scan).

Exclusion Criteria:

  1. Any pre-existing neurological illness resulting in a modified Rankin Scale Score of 3 or higher prior to the qualifying stroke
  2. Pregnancy
  Contacts and Locations
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Please refer to this study by its identifier: NCT01349946

United States, California
Stanford University School of Medicine
Stanford, California, United States, 94305
United States, Hawaii
The Queen
Honolulu, Hawaii, United States
United States, Illinois
Northwestern University
Chicago, Illinois, United States
United States, Oregon
Oregon Health Sciences University
Portland, Oregon, United States
United States, Pennsylvania
University of Pittsburgh Medical Center
Pittsburgh, Pennsylvania, United States
United States, Utah
University of Utah
Salt Lake City, Utah, United States
United States, Washington
Swedish Hospital
Seattle, Washington, United States
Sponsors and Collaborators
Stanford University
University of Pittsburgh
Northwestern University
University of Utah
Oregon Health and Science University
St. Luke's Medical Center
Queen's Medical Centre
Swedish Health Services
National Institute of Neurological Disorders and Stroke (NINDS)
Principal Investigator: Gregory W Albers Stanford University
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Gregory W Albers, MD, Professor of Neurology, Stanford University Identifier: NCT01349946     History of Changes
Other Study ID Numbers: SU-02082011-7478
R01NS039325 ( U.S. NIH Grant/Contract )
Study First Received: May 5, 2011
Last Updated: April 12, 2016

Additional relevant MeSH terms:
Cerebrovascular Disorders
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Vascular Diseases
Cardiovascular Diseases processed this record on August 23, 2017