Unstable angina--clinical manifestations and prognosis of 74 medically-treated patients

Seventy-four patients with unstable angina are reviewed. A rather high incidence (65%) of a changing pattern syndrome was observed in the study group. A history of prior myocardial infarction was obtained in 22 patients (30%). Fifty-seven patients (77%) were investigated using coronary angiography: 15 did not have any significant occlusive disease but are included in this study; single vessel disease was present in 20, double in 8 and triple in 14. Ten patients (13.5%) had myocardial infarcts which had occurred between 48 hours and 3 months after admission, and no patients died during this period. Patients who on admission had resting angina of new onset were more likely to have a worse short-term prognosis. Four patients underwent coronary bypass surgery in the first year of the follow-up period because of unsuccessful medical treatment. Six patients died within the first 4 years. Of the 6 deaths, 5 had triple vessel disease and one did not have any significant coronary stenosis. Mortality rate at 2 years was 2.7% and at 4 years 10.3%. This low mortality is probably attributable to a low incidence of 2- or 3-vessel disease.