Coronary arteriography in unstable angina pectoris
The National Unstable Angina Pectoris Study randomized 288 patients with unstable angina pectoris into one group receiving urgent surgery and another receiving intensive medical therapy. All patients had transient ST- or T-wave changes on the electrocardiogram during pain, and all had greater than 70% fixed luminal narrowing of at least one coronary artery at arteriography. Patients with 50% or greater luminal narrowing of the left main coronary artery were advised to have surgery. Patients with normal or insignificantly diseased coronary arteries, those with inoperable coronary artery disease, and those with left ventricular ejection fractions less than 30% were advised to have medical therapy.
This study demonstrated similar in-hospital and late myocardial infarction rates and similar in-hospital and late mortalities during an average 30-month follow-up. However, medical patients had a significantly higher incidence of severe (Class III or IV) angina during the follow-up period, and 36% of medical patients received elective surgery later for relief of incapacitating angina. No clinical or electrocardiographic phenomenon could identify those medical patients whose angina would eventually be inadequately controlled with an intensive medical program. The only significant correlate was the extent of coronary artery disease. Of the medical patients, 49% with three-vessel disease, 32% with two-vessel disease and 20% with one-vessel disease eventually turned to surgery for relief of unacceptable angina.
In the arteriographic evaluation of more than 500 patients who met the clinical and electrocardiographic criteria during the initial part of the National Study, 10% had left main coronary disease, 15% had normal or . . .