LOW-DOSE ACETYLSALICYLIC-ACID IN THE ANTITHROMBOTIC TREATMENT OF PATIENTS WITH STABLE ANGINA-PECTORIS AND ACUTE CORONARY SYNDROMES (UNSTABLE ANGINA-PECTORIS AND ACUTE MYOCARDIAL-INFARCTION)

Acetylsalicylic acid has an antithrombotic effect by inhibition of thromboxane A(2) synthesis in platelets. Thromboxane A(2) is a potent stimulator of platelet aggregation and vasoconstriction and synthesis may be completely inhibited by a single oral dose of 150 mg acetylsalicylic acid or an intravenous dose of 100 mg. A daily maintenance dose of 75 mg acetylsalicylic acid is sufficient to effectively inhibit thromboxane A(2) synthesis in long-term treatment. Acetylsalicylic acid therapy reduces acute myocardial infarction and sudden death in patients with stable angina pectoris and the drug is equally effective in patients with symptomatic and 'silent' angina pectoris. Early intervention with acetylsalicylic acid in patients with unstable angina pectoris reduces the risk of acute myocardial infarction and death. In patients with acute myocardial infarction, acute therapy with acetylsalicylic acid significantly reduces mortality both in monotherapy and in combination with thrombolytics. In the secondary prophylaxis following acute myocardial infarction, acetylsalicylic acid reduces the incidence of reinfarction and coronary death. Treatment of 100 patients with acute coronary syndrome (unstable angina pectoris or acute myocardial infarction) for 2 years may hinder the development of 3-4 fatal and 4 nonfatal vascular events. The risk of gastrointestinal side-effects and bleeding during acetylsalicylic acid therapy is dose-dependent and the incidence is low with a daily dose of 75-150 mg.