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Evidence summaries

Aspirin in Unstable Angina

Aspirin alone versus placebo reduces the risk of death, myocardial infarction, and stroke in people with unstable angina. Level of evidence: "A"

A topic in Clinical Evidence 1 summarizes the evidence on aspirin in unstable angina pectoris. One systematic review (search date 1990, 145 RCTs, 100000 people) 2 compared antiplatelet treatment versus placebo. Seven of these trials included a total of 4000 people with unstable angina. Antiplatelet treatment (mostly aspirin 75 - 325 mg daily) reduced the combined outcome of vascular death, myocardial infarction, or stroke at 6 months (AR 14% on placebo vs 9% on antiplatelet treatment, RR 0.65, 95% CI 0.51 to 0.79, NNT 20, 95% CI 15 to 34).

Clinical evidence category: Beneficial.

References

  • Natarajan M. Unstable angina. Clin Evid 2002 Jun;(7):214-26. [PubMed]
  • Collaborative overview of randomised trials of antiplatelet therapy--I: Prevention of death, myocardial infarction, and stroke by prolonged antiplatelet therapy in various categories of patients. Antiplatelet Trialists' Collaboration. BMJ 1994 Jan 8;308(6921):81-106. [PubMed]

Primary/Secondary Keywords