Bookmarkers beware: Bookmarks to pages other than the home page may not work after we change our server in April Editor's Choice | This Week in BMJ | Press releases BMJ No 7128 Volume 316 News Saturday 31 January 1998 Aspirin and warfarin best for primary prevention of heart attacks Combined treatment with warfarin and aspirin reduces the incidence of ischaemic heart disease and prevents more deaths from myocardial infarction among men at high risk than either agent on its own, according to results of the thrombosis prevention trial. More than 5,000 men aged 45-69 years took part in the Medical Research Council's general practice based study (Lancet1998;351:233-41). They were randomly assigned to receive low intensity oral warfarin (4.1 mg a day on average) and aspirin (75 mg daily), active warfarin and placebo aspirin, active aspirin and placebo warfarin, or a placebo for both drugs; they were followed for an average of seven years. The results show that the two agents produce independent effects. Aspirin reduced the incidence of ischaemic heart disease, mainly by preventing non-fatal episodes, whereas warfarin reduced it by preventing fatal events. Combined treatment had an impact on both fatal and non-fatal events. In real terms the authors found that about five events of ischaemic heart disease would be avoided by treating 1,000 high risk men with combined warfarin and aspirin for a year; about three episodes when patients are treated with warfarin alone; and three episodes when patients are treated with aspirin alone. In a commentary Professor Freek Verheught, from the department of cardiology at the University Hospital of Nijmegen in the Netherlands, said that the research shows that aspirin can be used effectively in the primary prevention of myocardial infarction among men at high risk. But he warned that the use of aspirin among the general population is inadvisable because only men have been investigated; the absolute risk of myocardial infarction is less than 0.5% per year; and aspirin does carry some risk of gastric discomfort and bleeding. He added that low intensity warfarin cannot be recommended for primary prevention of myocardial infarction because of the laborious monitoring involved. However, Professor Tom Meade, who headed the Medical Research Council's research team, disagreed: "If people are maintained on a low level of anticoagulant therapy [the international normalised ratio in the study was 1.5] then much less monitoring is needed than at present. In the study international normalised ratios were checked every three months, but it may be possible to extend the interval between clinic visits to, say, every four to six months." It may be worth considering a combination of aspirin and warfarin for some patients, added Professor Meade. "About a third of all people who have a first ischaemic heart disease event die - since we don't know who is going to die anything that is going to have an impact on the death rate is worth thinking about," he said. "A man in his late 40s with a family history of heart disease and who is anxious about having a heart attack is certainly worth considering for combination treatment - it is going to be cheaper than treatment with a statin." Zosia Kmietowicz London Home | Current issue | Past issues | Classified ads | Career Focus | Feedback Collections | About this site | About the BMJ | BMA | Medline