Advances in Stroke Prevention

8/4/2019 Advances in Stroke Prevention

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Advances in Stroke Prevention

Dr. G. Devathasan


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Stroke Subtypes by MRA/MRI/

U-S/Blood screen

A) Hemorrhagic --- small vessel rupture,AVMS, Aneurysms

B) Occlusive or Ischemic. Ask where the

source is (etiology)i) Carotids, arch, vertebrals

ii) Circle of Willis, basilarNote thedifferences in the behavior of the

endothelium at different sitesiii) Small vessel disease --- eventuallydiffuse leading to vascular dementia,Biswangers, amyloid, Cadasil


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iv) Cardiac embolivalvular, AFparoxysmal

v) Vasospasm TMA vs. TIAvi) Mixed leading to diffuseatherosclerosis

vii) Systemic Disordersantibody

syndromes. E.g. APA, abnormal clottingprofile, primary lipid disorders

viii) Venous disorders --- venous relatedinfarcts

ix) Trauma --- dissectionh) Inflammatory or unknown Takayasus,Moya-moya, etc


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Proposed Etiology of Primary

Hypertension

Chronic lack of fluid intake (not salt)Shrinkage of the blood volume

Renin/ angiotensin & other vasopressors

Arteriole spasmArteriole sclerosis

Atherosclerosis, Small vessel disease


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Management

Systolic below 140 & diastole below 85. Take

height & pulse rate into account. Avoidwatershed infarcts by hypotension

Fluids to be taken in generous portion of 3 litersper day in divided portions

Choice of antihypertensives from the ABCDgroupspersonal

ALLHAT study biased towards diuretics from itsdesign & analysis

All BP can be controlled with present range ofdrugs

Treat the labile & the nocturnal rise, especially ifassociated with sleep apnoea


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Powered vulgar word. More patientsimply dubious product. E.g. ALLHAT study

(19,000) 10 % dropout, especially thediuretic group

NNT or Number Needed to Treat --- Goodword & concept. 1/ARR

Double blind study required when aproduct does not speak for itself.Streptomycin, penicillin did not requiresuch studies

Meta-analyses; only successful studiespublished. Negative ones discarded bydrug companies

Statisticians not blinded. E.g. Caprie study


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Invariable influence of drug companies.

Disclaimer statements are insufficient Fabrications of data in reputable journals

not uncommon. Publish or perish pressureof Institutions. Classic example case of

H.S. of Bells Institute published 14fraudulent peered review articles in 18months in Science & Nature

There is still no substitute to astute clinical

experience & observation your feel of adrug


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Antiplatelets


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Meta-analyses

Antiplatelets Trialist collaboration (73,000)

27 % reduction risk composite outcome

Algral & al (10 trials)

16 % reduction composite outcome

Johnson & colleagues (500)

15 % reduction

Aspirin loses its value after 5 years

probably


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Thienopyridines


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Ticlopidine TASS after 1 year noadvantage over aspirin

CATS Ticlopidine vs. Placebo RRR 23 %

Cure trial end point not for strokes

Caprie: Plavix vs. Aspirin; no advantage &

Plavix appears to have no effect forstroke prophylaxis & more for PVD &coronary events

MATCH for combination therapy for TIAs

results pending But ACCP guidelines; Plavix is equal to

Aspirin


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Aspirin & Dipyrimadole

Earlier studies negative:

ESPS2 (Combination vs. Placebo) favorable results


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Warfarin (since 1924)

Bishydroxycoumarin

Rodenticide Clotting factors II, VII, IX, X

SPIRITS INR 3 - 4.5 negative study

WARSS; no advantage over Aspirin Subtypes PFO, cardiac & APA

WASID for intracranial stenosis subtypes

Retrospective study favorable;

prospective study pending ESPIRIT study pending


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Other Preventive Measures

Homocysteine lowering ?, HRA

GP 11b/111a receptor antagonists

trials abandoned


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Lipid Lowering Agents

Cholesterol is not a potent risk factor

Cardiovascular events should not beequated to cerebrovascular events

No substitute for leanness & diet

Small risk of Rhabdomylosis/Polyneuropathy

Higher risk of Hemorrhagic strokeswith cholesterol below 150 mg


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Non statins cholesterol lowering agentshad no impact on stroke outcome

Statins still dubious

E.g. Care study with Pravastatin (4159)

10.2 % vs. 13.2 % ARRR is 3 %

What it means is we need to treat 33

patients for a few years to prevent one

stroke case


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What then is the future?Carotid endarterectomy & stents

are of very limited value

Thrombolyticsrisk of Hemorrhage &Edema high


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Look at Plaque regression & in theCircle of Willis systolic peak velocityreduction

Manipulation of the autonomic(sympathetic) system. Nitric oxide


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Advances in Stroke Prevention

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