Arterial Revascularization of the Head and Neck by Horia Muresian

Author:Horia Muresian
Language: eng
Format: epub
Publisher: Springer International Publishing, Cham

Antithrombotic Treatment

Antiplatelet therapy is an establish treatment for secondary prevention after a TIA or stroke related to atherosclerotic large artery disease starting with trials like Dutch TIA [88], UK-TIA, [89], and ESPS2 [90] in the early 1990s, with a proven reduction stroke risk and death with small doses of aspirin (under 325 mg/day, usually 75–100 mg/day). Since then this treatment became a standard and also recommended in asymptomatic carotid stenosis (more than 50 % degree of stenosis) but not in isolated, asymptomatic, non-stenotic plaques where the risk-benefit ratio was less favorable and where treatment of risk factors (arterial hypertension, hypercholesterolemia with statins, cessation of smoking, diabetes treatment) is a better approach.

Since the ESPRIT [75] and WARSS [76] trials did not prove a superior effect of warfarin over aspirin (only similar results) in reducing the risk of stroke associated with cervical artery atheroma, and overall warfarin induced more frequent hemorrhagic events, oral anticoagulants (antivitamin K) are not an option for prevention of ischemic stroke in patients with cervical artery atherosclerosis.

In ESPS2 [90] aspirin and dipyridamole were more efficient than placebo, and their combination was more efficient than aspirin alone in reducing the risk of fatal and nonfatal stroke.

Clopidogrel 75 mg/day in the CAPRIE [91] phase III trial, compared with aspirin, reduced supplementary with about 8 % (but without reaching a statistical significance) the recurrence of an ischemic cerebral event, but had a significant reduction of the overall index of vascular deaths and vascular events in cerebral, coronary, and peripheral arterial beds. This study and further positive studies with combination of clopidogrel and aspirin in coronary heart diseases imposed clopidogrel as the drug of choice when ischemic large artery cerebral disease is combined with coronary or peripheral ischemia or when a patient has an “aspirin failure ” or intolerance.

The addition of aspirin 75 mg/day in patients already treated with clopidogrel 75 mg/day was compared with clopidogrel 75 mg/day alone in MATCH study [92], without supplementary reduction in ischemic cerebral event, but an increase in the hemorrhages rate, with an overall negative benefit. The same negative result was obtained for dual antiplatelet (clopidogrel and aspirin) versus aspirin in the CHARISMA trial [93] (including asymptomatic and symptomatic patients with atherosclerotic lesions of cerebral, coronary, and peripheral arteries) as overall result of the trial and also for patients with asymptomatic carotid atherosclerosis (part of the whole study). The result of these two studies emphasized that the association of clopidogrel and aspirin has an overall negative net benefit in the balance of prevented ischemic and induced hemorrhagic events and mortality, so it is not recommended in usual situation of asymptomatic atherosclerotic lesions of large artery or after a TIA or stroke.

A particular situation is the existence of a recent stent (carotid or coronary) or a recent (first year) myocardial infarction, situations where there is a clear indication for dual antiplatelet therapy (aspirin and clopidogrel if a previous stroke exists) with a duration depending on the stent type (bare metal stent or drug-eluting stent) and the associated risks of hemorrhage but generally extended to no more than 1 year after stent implantation.

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