Stroke Flashcards
What is a stroke?
sudden onset of FOCAL neurologic deficit resulting from the interruption of blood flow to an area in the brain
What are some symptoms of stroke?
hemiplegia
hemiparesthesia
blindness in one eye
speech disturbance
dizziness
weakness
headache
confusion
What is the acronym to remember the signs of stroke?
FAST
face drooping?
can you raise both arms?
is speech slurred?
time to call 911
What is the leading cause of disability?
stroke
Do people recover from stroke?
function may improve slowly over days-months
What is TIA?
transient ischemic stroke
focal neurologic deficit as a result of ischemia lasting less than 24hrs WITHOUT evidence of infarction on imaging studies
Is hemorrhage a likely cause of TIA?
no
hemorrhage stroke is unlikely to resolve itself within 24hrs
What are the chances of experiencing a stroke in the future if you had TIA?
7.5-17% within 3 months
If a person experienced TIA, how are they now considered?
now considered as secondary prevention
What are the types of stroke?
hemorrhagic (13%):
-higher death rate
-higher morbidity
-risk: aneurysm, HTN, medications (DAPT, OAC)
ischemic (87%):
-20% atherosclerosis
-30% cryptogenic
-20% cardioembolic
-25% lacunar
-5% other causes
What are conditions that can result in thrombus generation within or on the heart?
atrial fibrillation
mechanical heart valves
Describe cardioembolic stroke.
thrombi can break off and travel through aorta–>carotid artery–>small cerebral vessels
What are medications used to prevent cardioembolic stroke?
anticoagulants
-warfarin
-dabigatran
-rivaroxaban
-apixaban
What is the first decision that will be made in ER after someone has been diagnosed with stroke?
is the person eligible for thrombolytics?
What are the recommendations for the use of thrombolytics and stroke?
IV tPA is recommended provided that treatment is initiated within 3 hours of clearly defined symptom onset
therapy is also recommended between 3-4.5hrs of stroke except: >80yrs, OAC, severe stroke, history of stroke, diabetes
ASA usually delayed until 24hrs after tPA
What do plasminogen activators do?
convert plasminogen to plasmin
plasmin degrades fibrin into soluble products
What are examples of plasminogen activators?
alteplase (tPA)
-exact human sequence
-requires 1hr infusion time
tenecteplase
-longer acting fibrinolytic
-administered with one IV bolus dose
-recently shown “non-inferior” to tPA
What are the outcomes with the use of fibrinolytics in acute stroke?
if administered within 3-.4.5hrs will reduce risk for poor outcomes (disability, lack of recovery, neuronal damage)
if administered later, outcomes are not lower
Why is there explicit eligibility criteria for tPA?
due to the risk of bleeding
What is the eligibility for tPA?
clearly defined onset within past 3hrs
significant neurologic deficit
What are the contraindications to tPA?
rapidly improving
hemorrhage on CT
seizure at stroke onset
recent stroke or head injury (3 months)
recent GI/UTI bleed (3 weeks)
bp>185/110
low platelets
recent anticoagulation (2 days)
history of ICH
True or false: it is common to see tPA administered alongside an anticoagulant for stroke
false
What are the recommendations if someone is not eligible for tPA?
antiplatelet therapy is initiated
anticoagulation would be used instead for cardioembolic stroke
if hemorrhage has been ruled out
What are examples of antiplatelet agents?
COX inhibitors: ASA
ADP inhibitors: clopidogrel, prasugrel, ticagrelor
interference with cAMP: dipyridamole/ASA
GP IIb/IIIa antagonists
True or false: GP IIb/IIIa antagonists have no role in stroke
true
True or false: Aggrenox (dipyridamole/ASA) has a role in MI
false
studied in post-stroke
What is the antiplatelet of first choice in most cases when a person is ineligible for tPA?
ASA
Describe the pathway of arachidonic acid.
arachidonic acid can become COX-1 or COX-2
COX-1 produces thromboxane A2
COX-2 produces prostacyclin
How does ASA compare to other NSAIDs?
ASA is irreversible
little effect on COX-2 at low doses
How much does ASA reduce the risk in secondary prevention of stroke?
16%
ASA is used in secondary prevention of stroke in all patients, except who?
certain patients with afib/cardioembolic risks
hemorrhagic stroke
other CIs
What is the incidence of GI bleeds from ASA?
0.4% per year
What will put an individual at a greater risk of GI bleed from ASA?
higher dose (can occur with low doses)
hemostatic defect (hemophilia/low platelets)
previous GI bleed
drugs (anticoagulants)
age >60
uncontrolled HTN
CKD
True or false: ADP inhibitors do not cause GI bleeding, only NSAIDs do
false
What are the effects of prostacyclin (PgI2)?
inhibit acid secretion
enhance mucosal blood flow
promote secretion of cytoprotective mucous
What are the guidelines for antiplatelets in non-cardioembolic stroke (2ndry prevention)?
acceptable 1st line agents:
-aspirin 50-325mg OD
-Aggrenox BID
reasonable 2nd line therapy:
-clopidogrel 75mg OD
ASA+clopidogrel for first 21 days followed by ASA alone
-considered for 21 days in patients with minor stroke
-long term use is not recommended
What is dipyridamole?
MOA is controversial (PDE inhibitor or adenosine inhibitor or promoter of PGI2)
poor absorption from regular dosage forms
Aggrenox has modified release formulation
True or false: Aggrenox is possibly superior to ASA alone for secondary prevention of stroke
true
RRR 18% vs ASA
How frequently is Aggrenox administered?
BID (200mg/25mg)
Are ticagrelor or prasugrel recommended in stroke guidelines?
not currently recommended in stroke guidelines
evidence is emerging
not covered by Sask drug plan for stroke indication
much more costly than ASA 81mg OD
Describe low-dose ASA in secondary prevention of stroke based on the following: efficacy, safety, DI, convenience, CI, cost
efficacy:
-moderate effectiveness from RCT (may be slightly less
effective than Aggrenox)
-also indicated for prevention of ACVD events
-NOT very effective for cardioembolic conditions
safety:
-nuisance bleeding/bruising (common but not dangerous)
-major bleeding (mostly CNS or GI)
-GI bleeding in 0.4% in healthy, risk increases with disease/age
-GI bleed/ulceration often not painful
-CNS bleeding typically 1/10 of major bleeding (less common
but more dangerous
-at low doses, does not exhibit renal/bp effects of NSAIDs
DI:
-other antiplatelets/anticoagulants/NSAIDs/SSRIs
-methotrexate lvls increase with ASA but not likely 81mg
convenience:
-OD dosing but half life is short
CI:
-prior bleed
-uncontrolled HTN
-bleeding risk (low platelets, bleeding conditions, age)
cost:
-cheapest antiplatelet available
What is the role of DAPT in stroke?
used in:
-non disabling stroke
-high risk TIA
ASA+clopidogrel given within 24hrs and continued for 21 days
reduces 90d stroke risk from 7.8% to 5.2%
What are stroke patients at risk for and why?
venous thromboembolism due to paralysis/immobility
all patients with reduced mobility are given preventative therapy (low dose heparin, LMWH, IPC/ES)
What is the worst possible outcome of VTE?
pulmonary embolism
What are the recommendations around blood pressure control and stroke?
acute phase (onset to 72 hours):
-only extreme bp values are treated (>220/120)
-if thrombolysis is considered and bp >185/110
What are the current guidelines of treating blood pressure post-stroke?
strong consideration for treating everyone post-stroke regardless of bp
threshold bp>140/90
target <140/90
FIRST LINE: ACEI + TZD
What is the medication regimen of a patient for secondary stroke prevention?
blood pressure: ACEI+TZD (goal<140/90)
antiplatelet therapy
statins
smoking cessation (RRR 33%) and lifestyle intervention
Is antiplatelet therapy or anticoagulant therapy preferred for atherosclerotic stroke management?
antiplatelet therapy:
-showed lower risk of death or recurrent stroke at 2 yrs, major
bleed over 2 yrs, and any bleed over 2 yrs
When would warfarin or anticoagulants be used for stroke?
cardioembolic stroke
What is a common consequence of afib?
stroke
thus, almost all patients will receive stroke prevention even if they have never had a stroke
What is the only group of patients that will receive primary prevention for stroke?
afib
Describe the recommendations of primary prevention of stroke for afib.
CHADS-65–>OAC (have one of the following):
-CHF (heart failure)
-hypertension
-age 65
-diabetes
-prior stroke or TIA
none of the above:
-CAD or PAD–>antiplatelet
none of the above–>no antithrombotic
True or false: we use primary prevention of stroke or heart with ASA in virtually all patients
false
What is the regimen of secondary stroke prevention?
ABCKDE
antiplatelets
blood pressure (ACEI + thiazide)
cholesterol (statins)
diabetes
exercise/lifestyle/diet (RRR 33%)
