Aspirin does not extend benefits of clopidogrel
Adding aspirin to clopidogrel (Plavix) does not reduce the risk of secondary ischaemic events in high-risk cerebrovascular patients, new trial results show.
In addition, the study findings reveal that patients taking the combination
had significantly more life-threatening bleeds compared with those treated
with clopidogrel alone.
The results of the multinational MATCH trial (management of atherothrombosis
with clopidogrel in high-risk patients with recent transient ischaemic
attack or ischaemic stroke) were announced at a European
stroke conference in Mannheim, Germany, on 13 May.
The 7,599 patients involved had suffered a recent ischaemic stroke or
transient ischaemic attack (TIA) and were at high risk of further events
such as recurrent stroke or myocardial infarction (MI) because of risk
factors, which included previous ischaemic stroke or myocardial infarction,
symptomatic peripheral arterial disase, angina and diabetes.
All patients received clopidogrel 75mg once daily as part of standard
therapy and around half were randomised to receive aspirin 75mg daily,
with another group receiving placebo.
Although some previous trials had suggested the possibility of synergy
between aspirin and clopidogrel in high-risk patients, this study showed
that additional aspirin had no significant effects on preventing either
a combined endpoint of various ischaemic events or its components.
Presenting the trial results at the stroke conference, Hans Christoph
Diener, department of neurology, University of Essen, Germany, said that
although many doctors had traditionally used the combination of aspirin
and clopidogrel off licence, it was now shown not to be a good idea,
at least for long-term treatment (bleeding risks increased over time
in this 18-month trial).
Professor Diener said that he would be using aspirin as secondary prevention
in patients with a relatively low risk of further ischaemic events after
stroke. For those at higher risk, he would use clopidogrel monotherapy
for those with coronary artery disease such as angina, and he would use
a combination of dipyridamole and aspirin for other patients.
Professor Gary Ford, a stroke physician at Freeman Hospital, Newcastle,
said that the aspirin/clopidogrel combination remained appropriate for
some stroke patients — those who have had unstable angina or a
coronary stent inserted within recent months and those at very high risk
of stroke who have had continuing TIAs despite aspirin and dipyridamole
or clopidogrel and who are at low risk of bleeding complications and
where anticoagulation is not indicated. “This is a small group
of patients,” he added.
He advised that those who have had a stroke or a previous TIA should
discuss with their consultant or GP whether they should continue to take
the combination. |
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