Cardioprotection after myocardial infarction

Four classes of drugs—beta blockers, thrombolytic agents, acetyl salicylic acid, and anticoagulants—have demonstrated cardioprotective properties, preventing or limiting infarct development and reducing mortality. Beta blockers, studied in over 50 controlled randomized trials, reduced mortality and the incidence of reinfarction by 25% in more than 20,000 patients in whom therapy was initiated relatively late. In 27,000 patients who received intravenous beta-blocker therapy shortly after their arrival in the hospital, mortality was reduced an average of 13% within 1 week. Whether intervention was early or late, the beneficial effects of beta blockers were more marked in patients at higher risk, reducing mortality by as much as 30% in 2 weeks in patients with previous cardiovascular disease, diabetes, or complications at admission to the hospital. In more than 50 trials, mainly of streptokinase, in 50,000 patients with myocardial infarction, it has been demonstrated that early institution of thrombolytic therapy reduces mortality by about 25%. In 10 long-term studies in 18,500 patients, acetylsalicylic acid reduced the risk of reinfarction by 31% and mortality by 11%; very early administration of this agent had an even more marked effect on mortality, reducing it approximately 20%. A study comparing long-term treatment with warfarin to placebo found that it reduced postinfarct mortality by 24% and reinfarctions by 34%. Although bleeding complications are reported after therapy with thrombolytic agents, acetylsalicylic acid, and warfarin, the risk is low in selected patients. On the basis of these findings, beta blockers, thrombolytic agents, acetylsalicylic acid, and anticoagulants can be recommended for all patients without obvious contraindications.