[Natural history of unstable angina. Observations on 157 cases (author's transl)].

157 cases affected with "unstable angina" and hospitalized were observed over a period of from 8 to 24 months (average observation time: 16 1/2 months). The patients were treated with: nitroderivates, beta blocking drugs (when not contra-indicated); treatment of side affects (hypertension; arrhythmias, decompensation, associated pathology, correction of risk factors of coronary heart disease). 9 cases were lost and 148 were studied for the course of the illness. 10.6% died from cardiopathy (2.8% through sudden death; 7.4% from myocardial infarction); there was a 12.1% total incidence of myocardial infarction; 50% of the cases were alive but with sumptoms of stabilized angina, whilst 32.4% were completely asymptomatic. Coronographic alterations and myocardial contractility negatively affect the course of the illness. Negative effects (disease or infarction) were not checked in the cases of stenosis of only one coronary branch. In the casuistry, there were no negative effects in patients with stenosis of one coronary branch, and in cases of two or more branches, negative effects were 28%. 41% of patients with alterations of ventrical contractility gave negative results. An asymptomatic course of the illness was checked more frequently in the intermediate stages than in angina cases.