Prospective study of medical and urgent surgical therapy in randomizable patients with unstable angina pectoris: results of in-hospital and chronic mortality and morbidity.

At the Massachusetts General Hospital, all 190 patients who presented with the clinical and ECG criteria of the national Unstable Angina Pectoris Study (NUAPS) for unstable angina pectoris (UAP) were prospectively evaluated from their entrance between 1972 and 1976 (the entry period for NUAPS). Coronary angiography was performed in 166 patients. Of these, 83 patients (50%) were not eligible for randomization because of obstruction in the left main coronary artery (4%), inoperable diffuse coronary disease (11%), failure of initial medical therapy (20%), minimal coronary disease (13%), or other reasons (2%). The other 83 patients (50%) were eligible for randomization by NUAPS criteria; 39 received medical therapy and 44 underwent urgent coronary artery bypass surgery (CABG). The medical and surgical patients were comparable in terms of clinical characteristics and extent of anatomical disease. In-hospital (3% medical and 2% surgical) and late (5% medical and 5% surgical) mortality were similar over a mean follow-up period of 46 months. Myocardial infarction rate was statistically similar in-hospital (5% medical and 11% surgical) and during chronic evaluation (5% medical and 14% surgical). However, late severe angina (NYHA class III or IV) occurred in a significantly higher percentage of medical patients (28% medical versus 9% surgical; p less than 0.05) and nine medical patients (23%) required late elective CABG for relief of persistent angina. This experience is comparable to NUAPS, and supports the conclusion that acute management of unstable angina pectoris may begin with intensive medical treatment followed later by more elective CABG for those patients with persistent angina despite medical therapy.