Lipoprotein(a) is associated differentially with carotid stenosis, occlusion, and total plaque area.
BACKGROUND
Lipoprotein(a) [Lp(a)] is a putative risk factor for myocardial infarction and stroke and is related to thrombosis and impaired fibrinolysis. We studied relationships of Lp(a) with carotid stenosis, occlusion, and total plaque area, distinct phenotypes of atherosclerosis that may be differentially affected by cardiovascular risk factors.


RESULTS
Multivariable linear regression analysis was used to study relationships of Lp(a) to phenotypes of carotid atherosclerosis among 876 consecutive patients from an atherosclerosis prevention clinic with complete data for all variables used in the model. Occlusion of an internal carotid artery was present in 22 (2.5%) patients (one with bilateral occlusions). Risk factors predicted carotid plaque area, stenosis, and occlusion differently. Lp(a) was a significant independent predictor of baseline stenosis (P<0.0001) but not of plaque area (P=0.13); in logistic regression, Lp(a) significantly predicted occlusion (P=0.001). Patients with occlusion had significantly higher levels of Lp(a): 0.27+/-0.25 g/L versus 0.17+/-0.18 g/L without occlusion; P=0.007.


CONCLUSIONS
Lp(a) was a significant independent predictor of carotid stenosis and occlusion, but not of carotid plaque area, supporting the hypothesis that the effect of Lp(a) on atherogenesis and cardiovascular risk is largely related to thrombosis and impaired fibrinolysis. Stenosis and occlusion may not be attributable to plaque progression, but to plaque rupture and thrombosis; this relationship may also apply to other arterial beds.
Klein
Jonathan H
JH
Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada.
Hegele
Robert A
RA
Hackam
Daniel G
DG
Koschinsky
Marlys L
ML
Huff
Murray W
MW
Spence
J David
JD
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000473:pathology*; D016893:Carotid Stenosis / Q000150:complications / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D016014:Linear Models; D017270:Lipoprotein(a) / Q000097:blood*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D018570:Risk Assessment; D012307:Risk Factors; D012421:Rupture; D012720:Severity of Illness Index; D014463:Ultrasonography
D015415:Biomarkers; D017270:Lipoprotein(a)