Medical versus surgical treatment of unstable angina

A prospective, nonrandomized data bank study of the effect of medical versus surgical management of patients with unstable angina included all patients with unstable angina seen at 1 hospital over an 8 year period. Patients were entered into the study after an initial 5 day period of medical treatment. Entry characteristics were similar in 104 surgical patients and 124 medical patients. The mean follow-up period was 52 months. The operative mortality rate was 2% (2 of 104). The incidence of operative infarction was 13% (13 of 104). Twentyseven medical patients (22%) had late surgery for progressive angina without operative mortality. Seven year survival (Mantel-Haenszel) was 65% for the medical group and 85% for the surgical group when analyzed by initial treatment (p = 0.012). Analysis by the crossover method where crossover medical patients are followed up only to the date of surgery yielded similar results (p = 0.008). Nonsurvivors were compared with survivors and had a higher incidence of the following entry characteristics: (1) age greater than 60 years; (2) diastolic blood pressure greater than 89 mm Hg; (3) ST-T changes in the resting electrocardiogram; (4) 3 vessel disease; (5) elevated left ventricular diastolic pressure (at rest); and (6) elevated left ventricular diastolic pressure (exercise). None had single vessel disease. The incidence of infarction (fatal and nonfatal) in 5 years was 17% in the medical group and 22% in the surgical group. In the latter group 13% had a perioperative infarct and 9% had a late infarct. Symptom relief was greater in the surgical group. At 5 years 62% had no angina and only 8% had severe angina compared with 37% and 24%, respectively, in the medical group. Thus surgical management of selected patients with unstable angina appears preferable to medical therapy in view of improved survival and greater symptom relief. Whereas the total incidence of infarction was not reduced this was, in part, related to a 13% incidence of perioperative infarction. Improved methods of myocardial protection have since reduced this incidence to 3.0% in our hospital.