Unstable Angina and Progression of Coronary Atherosclerosis

We studied the progression of atherosclerotic coronary lesions in 38 patients who had previously undergone angiography and were later hospitalized for an episode of unstable angina pectoris, and in 38 matched patients with stable angina who had also undergone prior catheterization. Patients with unstable angina and those with stable angina were similar in terms of age (mean, 49 and 50 years, respectively), number of risk factors (1.5 per patient in both groups), interval between studies (mean ±S.D., 44±31 and 35±31 months, respectively), number of diseased vessels on the first angiogram (1.52 in both groups), and initial ejection fraction (65 and 63 per cent, respectively). Progression of coronary lesions was demonstrated in 29 of the 38 patients with unstable angina, as compared with 12 of the 38 with stable angina (P