Significance of adventitial inflammation of the coronary artery in patients with unstable angina: results at autopsy.

A quantitative analysis of adventitial inflammation of the coronary artery with intimal lesions is described in 12 patients who suffered coronary death and had had unstable angina (crescendo angina) at rest (group 1). After autopsy in these patients we examined epon-embedded cross sections by light and electron microscopy, paying particular attention to the adventitia, and compared these results with those in six patients who had had angina but died of noncardiac causes (group 2) and those in 22 patients who did not have angina (group 3). Of the 132 segments from group 1 patients, 39 (30%) were narrowed 76% to 100% by atherosclerotic plaque (group 2, 27%; group 3, 1%), and 23 (17%) had occlusive thrombi. Of the 264 sections (two from each segment) from group 1 that were examined, 98 (37%) (group 2, 15%; group 3, 9%) revealed clustered infiltration of inflammatory cells in the adventitia, half of which were associated with vascular nerve involvement. These findings in the adventitia may be related to the vasospastic component of unstable angina.