[Evaluation of treatments with beta-blockaders after myocardial infarction]

Beta-blockers have been used after myocardial infarction since 1965: however, it was not until the beginning of the 80s that the large multicentre clinical trials published results showing clearly their beneficial effects and leading to their widespread usage: betablockers significantly reduce the medium term (1 to 3 years) risk of death (-22 to -24%), especially sudden death (-32%) and the frequency of recurrent infarction (-27%). The cardio-protection so obtained is multifactorial, essentially related to their antiarrhythmic, antiischemic and antihypertensive effects. It has been established that beta-blockade should be instituted as soon as possible in the hours following the infarct (intravenous relayed by oral administration) and may be useful associated with aspirin. Although the large scale clinical trials did not determine the optimal dosage or the duration for which treatment should be administered, they did show that the groups of high risk patients were those to benefit the most from this therapy. Beta-blockers are usually well tolerated. However, it must be pointed out that 18% of patients were excluded from the two principal trials (only 25 to 30% of infarct patients were included) because of contraindications to beta-blockers and that 25 to 30% of the patients initially included had to interrupt the treatment because of side effects.