Bone formation in carotid plaques: a clinicopathological study.
OBJECTIVE
Bone formation and dystrophic calcification are present in carotid endarterectomy plaques. The clinical significance of these findings is unknown. The purpose of this study was to determine whether bone formation and extensive dystrophic calcification are associated with stable plaques and protective against ischemic vascular events.


METHODS
Carotid endarterectomy plaques were collected from 142 patients (94 men) with carotid stenosis. The specimens were evaluated for lamellar bone formation, dystrophic calcifications, inflammatory infiltrates, neovascularization, and histological type or grade of plaque according to a standard AHA grading system. Immunohistochemical staining was performed to identify vascular endothelial cells in neovascularization (factor VIII) and lymphocytes. Clinical data, including history of cerebrovascular and cardiovascular events, were recorded at the time of surgery.


RESULTS
Patients with calcification of carotid plaques had fewer symptoms of stroke and transient ischemic attack (P=0.042) than those without calcification. Stroke and transient ischemic attack occurred less frequently in patients with plaques with large calcific granules (P=0.021). Of the patients, 13% had lamellar bone formation, which directly correlated with the presence of sheetlike calcifications (P=0.0001) and inversely correlated with ulcerated lesions (P=0.048). The presence of bone also correlated with diabetes (P<0.01) and coronary artery disease (P<0.01). Of the 20 patients with bone, 6 had a history of stoke and transient ischemic attack (P=0.5).


CONCLUSIONS
The results indicate that bone formation tends to occur in heavily calcified carotid lesions devoid of ulceration and hemorrhage. Patients with extensive calcification of the carotid plaques are less likely to have symptomatic disease.
Hunt
Jennifer L
JL
University of Pittsburgh Medical Center, Department of Pathology and Laboratory Medicine, Philadelphia, USA.
Fairman
Ronald
R
Mitchell
Marc E
ME
Carpenter
Jeffrey P
JP
Golden
Michael
M
Khalapyan
Tigran
T
Wolfe
Megan
M
Neschis
David
D
Milner
Ross
R
Scoll
Benjamin
B
Cusack
Anita
A
Mohler
Emile R
ER
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001161:Arteriosclerosis / Q000150:complications / Q000473:pathology*; D002114:Calcinosis / Q000150:complications / Q000473:pathology*; D016893:Carotid Stenosis / Q000150:complications / Q000473:pathology* / Q000601:surgery; D003710:Demography; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D002546:Ischemic Attack, Transient / Q000150:complications; D008297:Male; D008875:Middle Aged; D010012:Osteogenesis; D011446:Prospective Studies; D012307:Risk Factors; D020521:Stroke / Q000150:complications