Improved aortocoronary bypass patency by low-dose aspirin (100 mg daily). Effects on platelet aggregation and thromboxane formation

Lancet. 1984 Jun 9;1(8389):1261-4. doi: 10.1016/s0140-6736(84)92446-2.


Prevention of aortocoronary bypass occlusion by aspirin (ASA, 1 X 100 mg per day) was studied in a prospective double-blind trial of 83 patients. 60 (72%) were randomly allocated to ASA or placebo starting 24 h after operation. 90% of grafts in the ASA group and 68% in the placebo group were patent at four months. At least one anastomosis was occluded in 62% of the patients on placebo and in 27% of those on aspirin. Ventricular arrhythmias increased after surgery in more patients on placebo (12/18) than in patients on ASA (5/17). Platelet thromboxane formation on collagen tested before operation was significantly higher in patients in whom bypass occlusion developed (occlusion: 40 +/- 19, no occlusion: 25 +/- 13 ng/ml). A 100 mg dose of ASA per day effectively blocked platelet thromboxane formation and thromboxane-supported aggregation on collagen and was safe in the postoperative phase. No side effects were reported throughout the trial. The reduced toxicity with full efficacy favours a low and infrequent dosage of aspirin.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aspirin / administration & dosage
  • Aspirin / pharmacology*
  • Blood Platelets / metabolism
  • Clinical Trials as Topic
  • Coronary Artery Bypass*
  • Double-Blind Method
  • Female
  • Graft Survival
  • Humans
  • Male
  • Middle Aged
  • Platelet Aggregation / drug effects*
  • Prospective Studies
  • Random Allocation
  • Thromboxanes / biosynthesis*


  • Thromboxanes
  • Aspirin