April 28, 2009Heart
Effective platelet inhibition by aspirin and clopidogrel: where are we now?
Key result
Antiplatelet therapy reduces major vascular events by an absolute ~2.5% in high-risk patients.
Why the study?
Does antiplatelet therapy non-response or resistance increase the risk of ischaemic events in patients with acute coronary syndromes?
Population
Patients with acute coronary syndromes (ACS) or at high risk for vascular events
Design
Review
Authors
Discussion
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Member takes
Implication
Supports antiplatelet therapy in high-risk patients; reinforces Level 1 evidence for vascular event reduction.
Key Points
- Review the therapeutic mechanisms, clinical validity, and management strategies related to resistance and non-response to aspirin and clopidogrel in cardiovascular disease.
- Synthesized molecular mechanisms and clinical trials targeting platelet activation pathways, including thromboxane A2, ADP, and glycoprotein IIb/IIIa receptors.
- Evaluated meta-analytic evidence from the Antithrombotic Trialists' Collaboration involving approximately 140,000 high-risk patients across 195 trials.
- Antiplatelet therapies collectively produce a significant 2.5% absolute reduction in major vascular events among high-risk patients.
- Clinical evidence supporting 'aspirin resistance' as a genuine driver of recurrent ischemic events remains weak and inconclusive.
- Identifiable patient subsets display low response or non-response to other antiplatelet agents like clopidogrel, which correlates with an increased risk of ischemic events including stent thrombosis.
Structured PICO
Does antiplatelet therapy non-response or resistance increase the risk of ischaemic events in patients with acute coronary syndromes?
P
Population
Around 140,000 high-risk patients for vascular events due to pre-existing disease or a recent vascular event from 195 trials.
I
Intervention
Antiplatelet therapy (aspirin and clopidogrel)
O
Outcome
Ischaemic events (death, myocardial infarction, urgent revascularisation, stent thrombosis)hard clinical
Main Result
Absolute Risk Reduction: 2.5
Absolute Risk Reduction: 2.5%
This review highlights that while true 'aspirin resistance' is weakly supported, non-response to other antiplatelet agents like clopidogrel is clinically relevant and may require tailored therapy.
Cite This Study
Briasoulis et al. (2009) conducted a review in High risk for vascular events (n=140,000). Antiplatelet therapy was evaluated on Major vascular events. Antiplatelet therapy yielded a significant 2.5% absolute reduction in the number of major vascular events among high-risk patients.