The natural history of carotid plaque development.

Fifty-seven carotid artery plaques in 54 patients were harvested at surgery and studied. Preoperative noninvasive findings, arteriograms, clinical symptoms, surgical findings, and light microscopic findings were compared. Thirty-four patients had symptoms, 28 with TIAs and six with a previous stroke. Thirty-three of the 34 had intraplaque hemorrhage, and 28 had a connection between the hemorrhage and the arterial lumen. Eleven of the 21 asymptomatic patients also had an intraplaque hemorrhage, and one had a connection. In eight of the 11, noninvasive studies showed progression of disease. The development of an intraplaque hemorrhage appears to be an important factor in an innocent plaque's becoming a clinically relevant one. If a connection develops between the intraplaque hemorrhage and the arterial lumen, the patient may have TIAs.