Angiographic changes in saphenous vein grafts and atherosclerosis risk factors - A 5-year study with serial measurements of serum lipids and lipoproteins

The association between cardiovascular risk factors and stenosis or occlusi on of saphenous vein grafts was analysed in a prospective 5-year study of 1 76 unselected patients with coronary artery bypass grafting (CABG). Methods included serial measurements of serum Lipids and lipoproteins, determinati on of apolipoprotein E phenotype, lipoprotein (a) levels 5 years postoperat ively, and subcutaneous fat biopsy to determine the fatty acid composition before and one year after CABG. Graft angiography with quantitative analysi s of angiograms was performed at the end of follow-up. A coronary artery wi th diameter less than or equal to 1.5 mm was associated with occlusion of v ein grafts (p < 0.01). The mean levels of serum lipids and lipoproteins, ot her traditional risk factors for atherosclerosis, and subcutaneous fatty ac id composition were similar in patients with and without graft occlusion, a nd similar when the maximum diameter of non-occluded grafts was <50% vs gre ater than or equal to 50%, and <25% vs greater than or equal to 25%. High l ipoprotein (a) concentration tended to be associated with obstructive chang es in vein grafts. Our data indicate that, because lipids, lipoproteins and other traditional cardiovascular risk factors do not predict occlusion or stenosis of saphenous vein grafts five years after CABG, it is not currentl y possible to predict directly from the levels of these risk factors which patients are likely to benefit from pharmacological or other interventions.