optimizing ed ischemic stroke patient care: horizons in 2007
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Optimizing ED Ischemic Stroke Patient Care: Horizons in 2007. FERNE Satellite Session. www.ferne.org. IEME Current Concepts in Emergency Care Maui, HI December 6, 2006. - PowerPoint PPT PresentationTRANSCRIPT
Edward P. Sloan, MD, MPH, FACEP
Optimizing ED Ischemic Optimizing ED Ischemic Stroke Patient Care: Stroke Patient Care: Horizons in 2007Horizons in 2007
Edward P. Sloan, MD, MPH, FACEP
www.ferne.orgwww.ferne.org
FERNE Satellite Session
Edward P. Sloan, MD, MPH, FACEP
IEMEIEMECurrent Concepts in Current Concepts in
Emergency CareEmergency Care
Maui, HIMaui, HIDecember 6, 2006December 6, 2006
Edward P. Sloan, MD, MPH, FACEP
Edward P. Sloan, MD, MPH FACEP
Professor
Department of Emergency MedicineUniversity of Illinois College of Medicine
Chicago, IL
Edward P. Sloan, MD, MPH, FACEP
Attending PhysicianEmergency Medicine
University of Illinois HospitalOur Lady of the Resurrection Hospital
Chicago, IL
Edward Sloan, MD, MPH, FACEP
DisclosuresDisclosures• Consultant to Baxter, Eisai, King Pharma, Novo Consultant to Baxter, Eisai, King Pharma, Novo
NordiskNordisk• Speaker’s bureau EisaiSpeaker’s bureau Eisai• FERNE President and Board ChairFERNE President and Board Chair• ACEP Clinical Policy CommitteeACEP Clinical Policy Committee• FERNE support from Astra Zeneca, Eisai, Novo FERNE support from Astra Zeneca, Eisai, Novo
Nordisk, UCB PharmaNordisk, UCB Pharma
Edward Sloan, MD, MPH, FACEP
Thank YouThank You• IEMEIEME• Marvin Wayne, MD (and Joan)Marvin Wayne, MD (and Joan)• Andrew Asimos, MDAndrew Asimos, MD• The FERNE staff:The FERNE staff:
• Charri, Carla, Jonathan, LiCharri, Carla, Jonathan, Li• Prior FERNE supportersPrior FERNE supporters• All of youAll of you
Edward P. Sloan, MD, MPH, FACEP
Clinical ObjectivesClinical Objectives• Treat patients quickly and effectively
• Minimize risk, complications
• Maximize outcome, resource utilization
• Enjoy our patient interactions and EM clinical practice
• Live long and prosper
Edward P. Sloan, MD, MPH, FACEP
Ischemic Stroke Pt CareIschemic Stroke Pt Care• Need to utilize tPA when applicable
• No more complicated therapeutic
• Risk of significant hemorrhage 50% that of imparting benefit
• New technologies exist
• Can these new diagnostics improve our ability to utilize this and other therapies?
Edward P. Sloan, MD, MPH, FACEP
Ischemic Stroke Ischemic Stroke PathophysiologyPathophysiology
• Cerebrovascular occlusion
• Core infarct: not salvageable
• Ischemic penumbra: salvageable
• Non-contrast CT cannot distinguish
• MRA and CTA may be able to
Edward P. Sloan, MD, MPH, FACEP
Diagnostics in ED CVA PtsDiagnostics in ED CVA Pts• Core dead infarct
• Surrounding ischemic penumbra
• Non-contrast CT cannot distinguish these
• MRA and CTA may be able to distinguish
• Therapies based on whether or not there is something to salvage
• This enhances tPA risk/benefit profile
Edward P. Sloan, MD, MPH, FACEP
Key Clinical QuestionsKey Clinical Questions• What do MRI and CTA/perfusion offer us
when determining optimal ischemic stroke patient therapies?
• Which test will become our standard of care in the future? Why?
Edward P. Sloan, MD, MPH, FACEP
CNS CT, MRI : The TestsCNS CT, MRI : The Tests
• CT with contrast
• CT angiography (CTA)
• MRI, without or with contrast
• MR angiography (MRA)
• Cerebral angiography
Edward P. Sloan, MD, MPH, FACEP
MRI/MRAMRI/MRA
Edward P. Sloan, MD, MPH, FACEP
Indications for MRI and CT Indications for MRI and CT in Emergent CNS in Emergent CNS Illness & Injury:Illness & Injury:
Beyond the Non-contrast CTBeyond the Non-contrast CT
Edward P. Sloan, MD, MPH, FACEP
Gary Strange, MD, FACEPGary Strange, MD, FACEP
ProfessorProfessor
Department of Emergency MedicineDepartment of Emergency MedicineUniversity of Illinois College of MedicineUniversity of Illinois College of Medicine
Chicago, ILChicago, IL
Edward P. Sloan, MD, MPH, FACEP
Edward P. Sloan, MD, MPH, FACEP
Large, Severe CVAsLarge, Severe CVAs
• Patients with acute stroke
• Moderate severity
• NIHSS ranges from 10-20?
• Acute hemorrhage must be excluded
• Thrombolytic therapy a consideration
• Can pt selection be optimized?
Edward P. Sloan, MD, MPH, FACEP
Non-Contrast Cranial CTNon-Contrast Cranial CT• Primary use is to rule out
acute hemorrhage– Contraindication to the use
of thrombolytic therapy– Identification of potential
surgical candidates
• Limited sensitivity for detecting acute cerebral ischemia (31-75%)
• tPA therapy
Edward P. Sloan, MD, MPH, FACEP
Acute Ischemic Stroke CTAcute Ischemic Stroke CT• Dense MCA sign• Decreased gray-white differentiation–Especially in the basal ganglia
• Loss of insular ribbon• Effacement of sulci• Edema and mass effect *• Large area of hypodensity* (>1/3 MCA)
*May signify increased risk of hemorrhage with thrombolytic therapy
Edward P. Sloan, MD, MPH, FACEP
Magnetic Resonance Imaging (MRI)Magnetic Resonance Imaging (MRI)
• Multimodal MRI
• Demonstrates hyperacute ischemia
• Considered less reliable in identifying early parenchymal hemorrhage
• What role does MRI play in diagnosis and management of the acute stroke pt?
Edward P. Sloan, MD, MPH, FACEP
MRI: Stroke Center ApproachesMRI: Stroke Center Approaches
• CT acutely with follow-up MRI –Late delineation of stroke findings
• Both CT and MRI acutely –More expensive, time-consuming
–Possible enhancements in therapy?
• MRI acutely –Is it a reasonable alternative?
Edward P. Sloan, MD, MPH, FACEP
What is Multimodal MRI?What is Multimodal MRI?• T1, T2 Imaging: Conventional weighted
pulse sequences
• DWI: Diffusion-Weighted Imaging
• PWI: Perfusion-Weighted Imaging
• GRE: Gradient Recalled Echo pulse sequence (T2*-sensitive)
• FLAIR: Fluid-Attenuated InversionRecovery images
Edward P. Sloan, MD, MPH, FACEP
T1 & T2 Weighted Pulse SequencesT1 & T2 Weighted Pulse Sequences
• Sensitive for subacute and chronic blood
• Less sensitive for hyperacute parenchymal hemorrhage?
• Probably adequately sensitive for acute bleed
Edward P. Sloan, MD, MPH, FACEP
Gradient Recalled Echo (GRE) Gradient Recalled Echo (GRE) Pulse SequencePulse Sequence
• May be sensitive for hyperacute parenchymal blood
• Detects paramagnetic effects of deoxyhemoglobin & methemoglobin as well as diamagnetic effects of oxyhgb
Edward P. Sloan, MD, MPH, FACEP
Gradient Recalled Echo (GRE) Gradient Recalled Echo (GRE) Pulse SequencePulse Sequence
• Core of heterogeneous signal intensity reflecting recently extravasated blood with significant amounts of oxyhgb
• Hypodense rim reflecting blood that is fully deoxygenated
Edward P. Sloan, MD, MPH, FACEP
Diffusion-Weighted ImagingDiffusion-Weighted Imaging• Ischemia decreases the
diffusion of water into neurons• Extracellular water accumulates• On DWI, a hyperintense signal• Present within minutes • Irreversible damage delineated• Non-salvageable tissue?• Infarct core
Edward P. Sloan, MD, MPH, FACEP
Perfusion-Weighted ImagingPerfusion-Weighted Imaging
• Tracks a gadolinium bolus into brain parenchyma
• PWI detects areas of hypoperfusion
–Infarct core (DWI area) and
–Ischemic penumbra
Edward P. Sloan, MD, MPH, FACEP
DWI/PWI MismatchDWI/PWI Mismatch
• Subtract DWI signal (infarct core) from the PWI signal (infarct core and ischemic penumbra)
• DWI/PWI mismatch is the hypoperfused area that may still be viable (ischemic penumbra)
Edward P. Sloan, MD, MPH, FACEP
DWI/PWI MismatchDWI/PWI Mismatch• Important clinical implications
• May identify the ischemic penumbra
• If there is a large mismatch, then reperfusion may be of benefit, even beyond the three hour tPA window
• If there is no mismatch, there may be little benefit to thrombolytic therapy, even within the three hour window
Edward P. Sloan, MD, MPH, FACEP
DWI/PWI MismatchDWI/PWI Mismatch
• DWI signal• PWI hypoperfused area
Edward P. Sloan, MD, MPH, FACEP
So what is the role of MRI in the ED So what is the role of MRI in the ED evaluation of the stroke patient?evaluation of the stroke patient?
• Secondary?– Initial CT to rule out hemorrhage
–Subsequent MRI to fully delineate ischemia, infarct and to follow treatment
• Primary?– Initial and possibly only imaging modality
Edward P. Sloan, MD, MPH, FACEP
MRI in Large, Severe CVAsMRI in Large, Severe CVAs
• Primary MRI not current EM standard
• Logistical, timing issues exist
• MRI likely able to diagnose hemorrhage
• DWI/PWI mismatch a promising exam
• Tailored thrombolytic therapy??
• Improved patient outcome??
Edward P. Sloan, MD, MPH, FACEP
CT Angiography & CT Angiography & CT PerfusionCT Perfusion
Andrew Asimos, MD, FACEP
Stroke Care after the 3 Hour Window Stroke Care after the 3 Hour Window for IV tPA Use: for IV tPA Use:
What are the Diagnostic and What are the Diagnostic and Therapeutic Options?Therapeutic Options?
Andrew Asimos, MD, FACEP
44thth EuSEM Congress EuSEM Congress
Crete, GreeceCrete, GreeceOctober 5-7, 2006October 5-7, 2006
Andrew Asimos, MD, FACEP
Andrew Asimos, MD, FACEP
Adjunct Associate Professor
Department of Emergency MedicineUniversity of North Carolina School of
Medicine at Chapel HillChapel Hill, NC
Andrew Asimos, MD, FACEP
Attending PhysicianEmergency Medicine
Carolinas Medical CenterDepartment of Emergency Medicine
Charlotte, NC
Andrew Asimos, MD, FACEP
DisclosureDisclosure• Will be discussing off label use of Will be discussing off label use of
approved devicesapproved devices
Andrew Asimos, MD, FACEP
Therapeutic WindowTherapeutic Window• Time from ictus used for practical Time from ictus used for practical
reasons in the EDreasons in the ED• Increasingly will rely on imaging studies Increasingly will rely on imaging studies
to determine ability to salvage at risk to determine ability to salvage at risk CNS tissueCNS tissue
Andrew Asimos, MD, FACEP
Advanced CT Imaging for Acute Stroke:Advanced CT Imaging for Acute Stroke:CTP versus MRICTP versus MRI
Parameters Definition of Penumbra
Advantages Limitations
CT Perfusion
CBF, CBV, MTT, TTP
Relative CBF <66%; CBV >2.5 mL/200g
•Combined with plain CT•Available•Fast
•Limited brain coverage•Poorly sensitive to posterior circulation•Indirect core visualization•Iodonated contrast
DWI-PWI MRI
CBF, CBV, MTT, TTP, ADC
Relative TTP (or MTT) delay >45s and normal DWI
•Sensitive•No radiation•Directly visualizes core
•Limited availability•CBF and CBV values not accurate•Patient cooperation required•Frequent contraindications
Muir KW et al. Lancet Neurology 2006; 5:755-768
Andrew Asimos, MD, FACEP
CT Angiography and CT PerfusionCT Angiography and CT Perfusion• Essential questionsEssential questions
• Is there hemorrhage?Is there hemorrhage?• Is there large vessel occlusion?Is there large vessel occlusion?• Is there “irreversibly” infarcted Is there “irreversibly” infarcted
core?core?• Is there “at risk” penumbra?Is there “at risk” penumbra?
• One contrast bolus yields two One contrast bolus yields two datasetsdatasets• Vessel patencyVessel patency• Infarct versus salvageable Infarct versus salvageable
penumbrapenumbra
Andrew Asimos, MD, FACEP
CT Angio & PerfusionCT Angio & Perfusion
Andrew Asimos, MD, FACEP
CT Perfusion TerminologyCT Perfusion Terminology
Blood FlowBlood Flow Blood VolumeBlood Volume Mean Transit TimeMean Transit Timeoror
Time to PeakTime to Peak
Andrew Asimos, MD, FACEP
DefinitionsDefinitions
PerfusionPerfusion The steady-state delivery of blood to The steady-state delivery of blood to cerebral tissue through the capillariescerebral tissue through the capillaries
Cerebral Blood Flow (CBF)Cerebral Blood Flow (CBF) Volume flow rate of blood through the Volume flow rate of blood through the cerebral vasculature per unit timecerebral vasculature per unit time
Cerebral Blood Volume (CBV)Cerebral Blood Volume (CBV) Amount of blood in a given amount of Amount of blood in a given amount of tissue at any timetissue at any time
Mean Transit Time (MTT)Mean Transit Time (MTT) Average time it takes for blood to Average time it takes for blood to traverse from the arterial to the traverse from the arterial to the venous side of the cerebral venous side of the cerebral vasculaturevasculature
Andrew Asimos, MD, FACEP
Ischemic Stroke Ischemic Stroke Cerebrovascular PathophysiologyCerebrovascular Pathophysiology
CBFCBF CBVCBV MTTMTT
Salvageable Salvageable PenumbraPenumbra
↓↓ ↑↑ ↑↑Nonviable Nonviable Core InfarctCore Infarct
↓↓ ↓↓ ↑ ↑ ↑↑
Andrew Asimos, MD, FACEP
Relationship between CBV, CBF, Relationship between CBV, CBF, and MTTand MTT
MTT= Blood Flow / Blood VolumeMTT= Blood Flow / Blood Volume
Blood FlowBlood Flow Blood VolumeBlood Volume Mean Transit TimeMean Transit Timeoror
Time to PeakTime to Peak
Andrew Asimos, MD, FACEP
Value of Perfusion ScanningValue of Perfusion Scanning
Andrew Asimos, MD, FACEP
Case:Case:Value of CTA/CTP within 3 hour windowValue of CTA/CTP within 3 hour window
• 50 yo male50 yo male• CT within hour of symptom CT within hour of symptom
onsetonset• Awake, alert, dysarthricAwake, alert, dysarthric• Fixed right sided gazeFixed right sided gaze• Left sided weaknessLeft sided weakness
Initial
Andrew Asimos, MD, FACEP
Case:Case:Value of CTA/CTP within 3 hour windowValue of CTA/CTP within 3 hour window
Andrew Asimos, MD, FACEP
Case:Case:Value of CTA/CTP within 3 hour windowValue of CTA/CTP within 3 hour window
BF BV TTPInitial
Andrew Asimos, MD, FACEP
Case:Case:Value of CTA/CTP within 3 hour windowValue of CTA/CTP within 3 hour window
BF BV TTP 3 day fuInitial
Andrew Asimos, MD, FACEP
Case:Case:“Wake up” Stroke“Wake up” Stroke
0735 at outside hospital
Andrew Asimos, MD, FACEP
Case:Case: “Wake up” Stroke “Wake up” Stroke
Andrew Asimos, MD, FACEP
Case:Case: “Wake up” Stroke “Wake up” Stroke
1030 at stroke center
Andrew Asimos, MD, FACEP
Case:Case: “Wake up” Stroke “Wake up” Stroke
24 hours later at stroke center
Andrew Asimos, MD, FACEP
Illustrative CTA/CTP Case #1Illustrative CTA/CTP Case #1• 50 yo male, remote CVA, in AF, not on 50 yo male, remote CVA, in AF, not on
coumadincoumadin• Presents 3 hours after symptom onsetPresents 3 hours after symptom onset• Awake, slurred speech, no aphasiaAwake, slurred speech, no aphasia• No field cut, right sided gaze, but able to No field cut, right sided gaze, but able to
pass midlinepass midline• Left facial droop, Left arm & leg 1/5 strengthLeft facial droop, Left arm & leg 1/5 strength• Right arm & leg 5/5 strengthRight arm & leg 5/5 strength• Left sided neglect with double Left sided neglect with double
simultaneous stimulationsimultaneous stimulation• NIHSSS 14NIHSSS 14
Andrew Asimos, MD, FACEP
Illustrative CTA/CTP Case #1Illustrative CTA/CTP Case #1
Andrew Asimos, MD, FACEP
Illustrative CTA/CTP Case #1Illustrative CTA/CTP Case #1
Andrew Asimos, MD, FACEP
CBVCBF MTT
Illustrative CTA/CTP Case #1Illustrative CTA/CTP Case #1
Andrew Asimos, MD, FACEP
Illustrative CTA/CTP Case #1Illustrative CTA/CTP Case #1
Edward P. Sloan, MD, MPH, FACEP
ConclusionsConclusions• Diagnostics may guide future therapies, esp
when onset time and penumbra size uncertain• May be able to maximize benefit and minimize
risk through greater understanding of infarct core and salvageable ischemic penumbra
• Future CTA use like non-contrast CT use today• Software for rapid reconstruction exists• MRI/MRA still has too many technical hurdles• EM physicians need to consider next steps
Edward P. Sloan, MD, MPH, FACEP
RecommendationsRecommendations• Determine what capabilities exist in your
institutions and access them• Consider these new diagnostics and your
interventional radiology capacities• Learn how to interpret these new tests
with your radiologists and neurologists• Move into the 21st century with greater
ability to maximize patient outcome
Thank you.Thank you.
[email protected]@ferne.org
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ferne_ieme_2006_sloan_strokehorizons_120606_edited_finalcd 04/21/23 01:35 Edward P. Sloan, MD, MPH, FACEP
Edward P. Sloan, MD, MPH, FACEP
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