Homocysteine, a risk factor for carotid atherosclerosis, is not a risk factor for early recurrent carotid stenosis following carotid endarterectomy.

Homocysteine has been proposed as a risk factor for atherosclerotic disease and recurrent coronary stenosis due to neointimal hyperplasia following angioplasty. In order to evaluate homocysteine's role in human carotid neointimal hyperplasia, we have compared homocysteine levels in patients who have not developed restenosis with those who have within 2 years of carotid endarterectomy (CEA). One hundred and fifty-four patients were divided into 3 groups based on duplex scans performed 2 years after CEA. Group I (88) were patients in whom all scans showed no evidence of restenosis. Group II (35) patients exhibited some restenosis, but this did not exceed 49% diameter reduction based on our duplex criteria. Group III (31) patients developed a restenosis of > 50% within 2 years. One hundred and thirteen Dacron patches (73 Group I [83%], 22 Group II [63%], and 18 Group III [58%]) were used according to surgeon preference but did not affect the statistical relevance of homocysteine evaluation. The groups were otherwise identical in terms of age, sex, smoking history, and cholesterol levels. All patients were receiving antiplatelet medication postoperatively, and none had consumed added pharmacologic folate. The average homocysteine value for the entire study group was elevated at 12.5 micromol/L. The homocysteine values for the 3 groups were not statistically different (p > 1): (I, 12.5; II, 12.2; and III, 12.9 micromol/L). Elevated homocysteine levels (> 10 micromol/L) appear to be associated with carotid atherosclerosis, but at levels < 30 micromol/L do not appear to play a role in restenosis following CEA.