Clinical Question:
Does adding clopidogrel (Plavix) to aspirin improve short-term outcomes in
patients with acute myocardial infarction?
Bottom Line:
In a wide range of patients with acute MI, adding clopidogrel 75 mg daily to
aspirin and other standard treatments (such as fibrinolytic therapy) safely
reduces mortality and major vascular events in hospital, and should be
considered routinely.
Reference:
Addition of clopidogrel to aspirin in 45,852 patients with acute myocardial
infarction: randomised placebo-controlled trial.Chen ZM, Jiang LX, Chen YP,
Xie JX, Pan HC, Peto R, Collins R, Liu LS; COMMIT (ClOpidogrel and
Metoprolol in Myocardial Infarction Trial) collaborative group. Lancet. 2005
Nov 5;366(9497):1607-21.
Study Design:
Randomized controlled trial (double-blinded)
Synopsis:
Despite improvements in the emergency treatment of myocardial infarction
(MI), early mortality and morbidity remain high. The antiplatelet agent
clopidogrel adds to the benefit of aspirin in acute coronary syndromes
without ST-segment elevation, but its effects in patients with ST-elevation
MI were unclear. 45,852 patients admitted to 1250 hospitals within 24 h of
suspected acute MI onset were randomly allocated clopidogrel 75 mg daily
(n=22,961) or matching placebo (n=22,891) in addition to aspirin 162 mg
daily. 93% had ST-segment elevation or bundle branch block, and 7% had
ST-segment depression. Treatment was to continue until discharge or up to 4
weeks in hospital (mean 15 days in survivors) and 93% of patients completed
it. The two prespecified co-primary outcomes were: (1) the composite of
death, reinfarction, or stroke; and (2) death from any cause during the
scheduled treatment period. Comparisons were by intention to treat, and used
the log-rank method. This trial is registered with ClinicalTrials.gov,
number NCT00222573. Allocation to clopidogrel produced a highly significant
9% (95% CI 3-14) proportional reduction in death, reinfarction, or stroke
(2121 [9.2%] clopidogrel vs 2310 [10.1%] placebo; p=0.002), corresponding to
nine (SE 3) fewer events per 1000 patients treated for about 2 weeks. There
was also a significant 7% (1-13) proportional reduction in any death (1726
[7.5%] vs 1845 [8.1%]; p=0.03). These effects on death, reinfarction, and
stroke seemed consistent across a wide range of patients and independent of
other treatments being used. Considering all fatal, transfused, or cerebral
bleeds together, no significant excess risk was noted with clopidogrel,
either overall (134 [0.58%] vs 125 [0.55%]; p=0.59), or in patients aged
older than 70 years or in those given fibrinolytic therapy.
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