Antiplatelet

Posted On February 22, 2020

Aspirin:

• only agent established as effective for early treatment of acute ischemic stroke.
• Should be given asap if no bleed
• No Aspirin for 24 hours after tpa
. Optimal dose not clear, 50 to 325 mg as effective as higher dose

For Asian patients with high-risk TIA or minor stroke (ie, NIHSS score < 3)

= Consider dual antiplatelet treatment, rather than aspirin alone
– clopidogrel (300 mg loading dose, then 75 mg daily) plus aspirin (75 to 300 mg loading dose, then 75 to 81 mg daily) for 21 days
– – followed by clopidogrel monotherapy (75 mg daily) through at least day 90

After ischemic stroke and TIA, for secondary stroke prevention

= aspirin or
= clopidogrel 75 mg qd (Plavix) (<$10 for 30) or
= aspirin with extended-release dipyridamole 25/200 mg bid (generic cost $130 for 60 cap)

Double antiplatelet Rx:

  • clopidogrel + Aspirin vs aspirin alone
    • increased annual rate of both major hemorrhage (2.1 versus 1.1 percent)
    • all-cause mortality (2.1 versus 1.4 percent)
    • Do not use double antiplatelet for lacunar (subcortical) stroke (SPSC3 trial)
  • May be reasonable to use for short term for
    • Transient Ischemic Attack or minor ischemic stroke for 21 days (per 2019 AHA/ASA recommendation)
    • Intracranial stenosis > 70%: use for 90 days
    • Acute MI or stent, use double antiplatelet for 12 months, longer if indicated

A summary of trials:

MATCH trial:-

  • •7599 patients with stroke or TIA plus risk feature,
  • randomly assigned to clopidogrel (75 mg daily) plus aspirin (75 mg daily) versus clopidogrel (75 mg daily) alone.
  • Follow-up 18 months.
  • double agents did not reduce the risk of major vascular events
  • significant increase in life-threatening bleeding complications, mainly intracranial and gastrointestinal
  • Over 18-month, increase of 1.3 percent for life-threatening hemorrhage

CHARISMA trial:

  • aspirin plus clopidogrel versus aspirin alone
  • 15,603 patients with cardiovascular disease (coronary, ischemic cerebrovascular, or peripheral arterial) or, in 21 percent of patients, multiple atherothrombotic risk factors (eg, diabetes, hypertension, primary hypercholesterolemia, current smoking, asymptomatic carotid stenosis)
  • Double agents did not reduce the risk of the composite primary end point (MI, stroke of any cause, or death from cardiovascular causes) compared with aspirin alone (6.8 versus 7.3 percent)
  • Double agent: significant increase in moderate bleeding (2.1 versus 1.3 percent) and a nonsignificant increase in severe bleeding (1.7 versus 1.3 percent)

SPS3 trial:

  • over 3000 patients with subcortical (ie, lacunar) stroke confirmed by MRI
  • combination of aspirin plus clopidogrel versus aspirin alone was terminated before completion because of a higher frequency of bleeding events (mostly systemic) and a higher mortality rate in patients on dual antiplatelet therapy

Two small trials

  • CARESS and CLAIR:
    • patients with recently symptomatic large artery stenosis
    • compared with aspirin alone, early treatment with aspirin plus clopidogrel reduced the number of microembolic signals detected on transcranial Doppler ultrasound.
  • whether this surrogate measure would translate into clinical benefit for patients with symptomatic large artery stenosis remains uncertain.

updated 01/18/2022

Tags: