Revisiting Current Golden Rules in Managing Acute Ischemic Stroke: Evaluation of New Strategies to Further Improve Treatment Selection and Outcome.
OBJECTIVE
Advanced stroke imaging has generated much excitement for the early diagnosis of acute ischemic stroke (AIS) and facilitation of intervention. However, its therapeutic impact has not matched its diagnostic utility; most notably, lacking significant contributions to recent major AIS clinical trials. It is time to reexamine the fundamental hypotheses from the enormous body of imaging research on which clinical practices are based and reassess the current standard clinical and imaging strategies, or golden rules, established over decades for AIS. In this article, we will investigate a possible new window of opportunity in managing AIS through a better understanding of the following: first, the potential limitations of the golden rules; second, the significance of imaging-based parenchymal hypoperfusion (i.e., lower-than-normal relative cerebral blood flow [rCBF] may not be indicative of ischemia); third, the other critical factors (e.g., rCBF, collateral circulation, variable therapeutic window, chronicity of occlusion) that reflect more individual ischemic injury for optimal treatment selection; and, fourth, the need for penumbra validation in successfully reperfused patients (not in untreated patients).


CONCLUSIONS
Individual variations in the therapeutic window, ischemic injury (rCBF), and chronicity of vascular lesion development have not been comprehensively incorporated in the standard algorithms used to manage AIS. The current established imaging parameters have not been consistently validated with successfully reperfused patients and rCBF to quantitatively distinguish between oligemia and ischemia and between penumbra and infarct core within ischemic tissue. A novel paradigm incorporating rCBF values or indirectly incorporating relative rCBF values with higher statistically powered imaging studies to more reliably assess the severity of ischemic injury and differentiate reversibility from viability within the area of imaging-based parenchymal hypoperfusion may provide a more personalized approach to treatment, including no treatment of infarction core, to further enhance outcomes.
1 Department of Radiology, University of Washington, 1959 NE Pacific St, Rm NW011, Seattle, WA 98195.
William T C
WT
Yuh
2 Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA.
Matthew David
MD
Alexander
3 Department of Strokology, St. Marianna University, Tokyo Hospital, Kawasaki, Japan.
Toshihiro
T
Ueda
4 Department of Advanced Diagnostic Imaging, Mie University School of Medicine, Mie, Japan.
Masayuki
M
Maeda
5 Department of Radiology, Nara Medical University, Nara, Japan.
Toshiaki
T
Taoka
6 Department of Radiology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Kei
K
Yamada
1 Department of Radiology, University of Washington, 1959 NE Pacific St, Rm NW011, Seattle, WA 98195.
Norman J
NJ
Beauchamp
D000792:Angiography / Q000592:standards*; D000066491:Clinical Decision-Making / Q000379:methods*; D006801:Humans; D009462:Neurology / Q000592:standards*; D018579:Patient Selection; D017410:Practice Guidelines as Topic; D020521:Stroke / Q000000981:diagnostic imaging* / Q000628:therapy*; D014481:United States
acute ischemic stroke; diffusion imaging; diffusion-perfusion mismatch infarct core; oligemia; penumbral imaging; perfusion imaging; therapeutic window