Homocysteine levels, haemostatic risk factors and restenosis after carotid thrombendarterectomy.
OBJECTIVE
To investigate the effect of elevated serum homocysteine and haemostatic as well as clinical risk factors on the tendency to restenosis after carotid artery thrombendarterectomy.


METHODS
A prospective, observational study.


METHODS
In the period from October 1999 to October 2002, 86 patients were subjected to 96 carotid endarterectomies because of internal carotid artery stenoses. The carotid stenoses were symptomatic in 86 cases (90%). Fasting plasma homocysteine, fibrinogen, D-dimer and activated protein C resistance were measured the day before surgery. Follow-up was done 1, 3, 6, 12 and 18 months postoperatively and yearly thereafter with clinical assessment and triplex ultrasonography. The median follow-up time was 17 months (range 9-42 months). Freedom from restenosis was estimated with Kaplan-Meier curves, using log-rank test for comparison between groups. Variables found to be significantly related to restenosis rates were included in a multivariate analysis performed with the Cox proportional hazards model. Comparison of means of continuous data between two groups was done with Student's t-test and more than two groups with one-way analysis of variance.


RESULTS
Restenoses within 12 months of the operation occurred in 11 cases (11%). Univariate analysis revealed that plasma homocysteine values < or =10 micromol/l and freedom from ischaemic heart disease were both significantly associated with an increased risk of restenosis (p=0.0076 and 0.0059). However, multivariate analysis showed that only plasma homocysteine values <10 micromol/l were independently and significantly associated with an increased risk of restenosis (p=0.046). There were no associations between the degree of atherosclerotic affection of the precerebral circulation or symptoms on one hand and the levels of homocysteine, fibrinogen, D-dimer and activated protein C resistance on the other.


CONCLUSIONS
There seems to be an independent, significant association between homocysteine values within the lower two thirds of the normal range and restenosis after carotid endarterectomy. Studies on the biological properties of human endothelial cells from different types of vasculature and different locations, specifically with respect to homocysteine metabolism and its effect, are warranted.
Department of Vascular Surgery, Haukeland University Hospital, Bergen, Norway.
E
E
Laxdal
G E
GE
Eide
S R
SR
Amundsen
E B
EB
Dregelid
G
G
Pedersen
T
T
Jonung
S
S
Aune
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016893:Carotid Stenosis / Q000097:blood* / Q000601:surgery*; D016894:Endarterectomy, Carotid; D005260:Female; D006487:Hemostasis; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors; D013997:Time Factors; D014654:Vascular Patency
D006710:Homocysteine