[Unstable angina: effect of aspirin and heparin on treatment outcome in hospital patients (a double-blind, placebo-controlled study)].

Aspirin and heparin are regarded as drugs that improve a prognosis in patients with unstable angina, but their comparative efficiency has not been elucidated yet. A randomized double-blind placebo-controlled study of oral aspirin (165 mm once daily) versus intravenous infusion of heparin (1,000 units per hour) was carried out in 94 patients with acute unstable angina (the mean interval after the last anginal attack 5.7 +/- 4.6 hours). During hospital stay, cardiac events (Q wave myocardial infarction or cardiac death) developed in 6 out of 46 patients on aspirin and 6 out of 48 patients on heparin. A significant superiority of heparin during its infusion (1 case of myocardial infarction versus 4 on aspirin) disappeared during the following 24 hours when 2 patients on heparin developed myocardial infarction (due to rebound phenomenon?). Two patients on heparin underwent coronary artery bypass surgery. Among complications only minor bleeding occurred. The results of this study demonstrated no significant benefits of intravenous heparin infusion over oral aspirin during hospitalization in patients with unstable angina. A high incidence (13%) of poor outcomes observed with the two drugs indicates that it is necessary to search for more beneficial antithrombic interventions.