The Aspirin Myocardial Infarction Study (AMIS)
Objectives:
The Aspirin Myocardial Infarction Study (AMIS) was a
National Heart, Lung and Blood Institute-sponsored, multicenter, randomized,
double-blind, and placebo-controlled trial designed to test whether the regular
administration of aspirin to men and women who had experienced at least one
documented myocardial infarction (MI) would result in a significant reduction
in total mortality over a three-year period. Cause-specific mortality, nonfatal
events, and side effects were also evaluated.
Background:
There was preliminary evidence that regular
administration of aspirin may be of benefit to patients with known coronary
heart disease. In addition, there was considerable evidence that platelet
aggregation and platelet-induced thrombosis may play a role in several clinical
events associated with coronary heart disease. Aspirin can inhibit the
formation of prostaglandin endoperoxides and thromboxane A, which aggregate
platelets and induce vasospasm, but the clinical pharmacology of the drug is
further complicated by recent findings that it also blocks the synthesis of
prostacyclin, an inhibitor of platelet aggregation and a vasodilator that is
produced in blood vessles. Based on the encouraging but inconclusive clinical
findings and the anti-platelet properties of aspirin, the AMIS Study was
initiated in 1975.
Subjects:
Over a 13-month period, 4,524 persons between the ages
of 30 and 69 years were randomized to either 1 g of aspirin per day (2,267
persons) or placebo (2,257 persons). High levels of patient compliance to study
protocol were indicated by various measures.
Conclusions:
Based on AMIS results, aspirin is not recommended for
routine use in patients who have survived an MI. Total mortality during the
entire follow-up period was 10.8% in the aspirin group and 9.7% in the placebo
group. Three-year total mortality was 9.6% in the aspirin group and 8.8% in the
placebo group. The percentage of definite nonfatal MI was 8.1% in the placebo
group and 6.3% in the aspirin group. Coronary incidence (coronary heart disease
mortality or definite nonfatal MI) was 14.1% in the aspirin group and 14.8% in
the placebo group. (JAMA 1980; 243:661-669.)
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Study Website |
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Study Documentation |
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Data Distribution Agreement |
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