Monday, April 07, 2014

Stroke care: nuances, practical aspects and pearls

These are some points from S. Andrew Josephson 's talk at the 17th Annual UCSF hospital medicine course.

Timeline for interventions

Acute ischemic stroke time windows:

0-4.5 hr IV thrombolysis (I acknowledge the controversy that still rages about this. I'll save it for another discussion).

0-6 hours intra arterial thrombolysis (stroke guideline class I for MCA occlusions not otherwise eligible for IV lysis).

0-8 hours mechanical embolectomy (class IIa for those not eligible for lytics).

And here's what the 2013 stroke guidelines say about the interventional treatments including rescue:

Intra-arterial fibrinolysis is beneficial for treatment of carefully selected patients with major ischemic strokes of less than 6 hours’ duration caused by occlusions of the MCA who are not otherwise candidates for intravenous rtPA (Class I; Level of Evidence B). The optimal dose of intra-arterial rtPA is not well established, and rtPA does not have FDA approval for intra-arterial use. (Revised from the previous guideline13) 
As with intravenous fibrinolytic therapy, reduced time from symptom onset to reperfusion with intra-arterial therapies is highly correlated with better clinical outcomes, and all efforts must be undertaken to minimize delays to definitive therapy (Class I; Level of Evidence B). (New recommendation)
Intra-arterial treatment requires the patient to be at an experienced stroke center with rapid access to cerebral angiography and qualified interventionalists. An emphasis on expeditious assessment and treatment should be made. Facilities are encouraged to define criteria that can be used to credential individuals who can perform intra-arterial revascularization procedures. Outcomes on all patients should be tracked (Class I; Level of Evidence C). (Revised from the previous guideline13)
When mechanical thrombectomy is pursued, stent retrievers such as Solitaire FR and Trevo are generally preferred to coil retrievers such as Merci (Class I; Level of Evidence A). The relative effectiveness of the Penumbra System versus stent retrievers is not yet characterized. (New recommendation)
The Merci, Penumbra System, Solitaire FR, and Trevo thrombectomy devices can be useful in achieving recanalization alone or in combination with pharmacological fibrinolysis in carefully selected patients (Class IIa; Level of Evidence B). Their ability to improve patient outcomes has not yet been established. These devices should continue to be studied in randomized controlled trials to determine the efficacy of such treatments in improving patient outcomes. (Revised from the previous guideline13)
Intra-arterial fibrinolysis or mechanical thrombectomy is reasonable in patients who have contraindications to the use of intravenous fibrinolysis (Class IIa; Level of Evidence C). (Revised from the previous guideline13)
Rescue intra-arterial fibrinolysis or mechanical thrombectomy may be reasonable approaches to recanalization in patients with large-artery occlusion who have not responded to intravenous fibrinolysis. Additional randomized trial data are needed (Class IIb; Level of Evidence B). (New recommendation)

Note that the rescue therapies are IIb and the speaker said we should “probably not” be using them at present with the exception of basilar lesions.

Informed consent

Informed consent for IV thrombolysis is vital. Because time for discussion is limited, graphics such as this one are useful (from this paper).

Who needs a TEE? When is TTE enough?

TEE is far superior to TTE for detection of an indication for systemic anticoagulation. For practical purposes, according to the speaker, a selective approach can be used and he presented UCSF's protocol:

Cryptogenic clinically large vessel stroke, age under 55, no known a fib: TEE.

For patients 55 and older with cryptogenic clinically large vessel stroke and no a fib get a TTE. Stop there if no LV systolic dysfunction, LVH, left sided valvular stenosis, left sided valvular regurgitation (or only mild), prosthetic valve or LAE (over 40mm). Otherwise TEE. If TTE shows intracardiac mass or veg TEE may still be necessary if warfarin indication unclear.

A fib detection

In cryptogenic stroke if echo eval is negative and inpatient telemetry shows no a fib: extended day outpatient event monitor. The cost effectiveness of such an approach was shown in this analysis.

Indications for anticoagulation are diminishing

Chronic: A fib, thrombus seen in heart. For PFO (even with atrial septal aneurysm): questionable. For artery dissection: maybe. For hypercoagulable states: only if antiphospholipid syndrome.

Acute: none. Not even if the patient has a fib (in such a case just put them on warfarin and let the INR drift out).

What about target specific oral anticoagulants in this setting (secondary prevention)? Data are scant.

Antiplatelet therapy 

What about the CHANCE study? The speaker says this approach is not ready for prime time and we need to wait for the POINT trial results.

What if the patient with acute stroke is already on aspirin? He recommends a switch to plavix or aggrenox. If the patient is already on plavix or aggrenox there is no published experience to guide us.

Lipid management

80 mg atorvastatin for almost everyone.

Permissive hypertension in CVA

In the non-TPA ischemic stroke patient treat 220/120 but not anything lower initially, unless their's some other indication (e.g. cardiac emergency). What if it's just a TIA? He still advocates for permissive HT but says sometimes he “fudges” a little.


Treatment approach essentially same as stroke, conceptually. 30-50% will have infarct on MRI.

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