Serum Lp(a) level as a predictor of vein graft stenosis after coronary artery bypass surgery in patients.

Abstract

Although the serum lipoprotein fraction Lp(a) has been associated with coronary artery atherosclerosis, its relationship to narrowing of saphenous vein grafts has not previously been elucidated. We therefore measured serum Lp(a) levels in 167 symptomatic patients undergoing cardiac catheterization who had had coronary artery bypass surgery 0.7 to 14.3 years earlier. Lp(a), total cholesterol, and total triglyceride levels were compared with the degree of saphenous vein graft stenosis to test for any association. Serum Lp(a) levels were significantly associated with the degree of stenosis of saphenous vein grafts (r = .24, p = .002). Mean Lp(a) levels (mg/dl) in the 135 patients with stenosis were almost double (32.0 + 32.7 mean ± SD) those in the 32 patients with no graft stenosis (16.7 ± 22.6; p = .002). Graft stenosis was not associated with previous myocardial infarction, hypertension, obesity, diabetes, or smoking. Serum cholesterol levels (mg/dl) were slightly higher in the stenosis group (251.3 ± 69) than in the no-stenosis group (231.8 ± 48.8), but the difference was of borderline significance (p = .06). A stepwise increase in mean Lp(a) was found in groups of patients with increasing vein graft stenosis. At a serum Lp(a) level of 31.6 mg/dl or above, 92% of the patients demonstrated vein graft stenosis. Thus, patients with elevated Lp(a) levels have an increased risk of developing saphenous vein graft stenosis after coronary bypass surgery. Circulation 77, No. 6, 1238-1244, 1988 AORTOCORONARY BYPASS with saphenous veins is currently the most widely used procedure for revascularizing the myocardium.'-' However, the clinical outlook for such patients has been somewhat dampened by recent reports of long-term patency that indicate that at 10 years or more after surgery, only about 60% of grafts remain patent,3'4 and that nearly one-half of the patent grafts show angiographic evidence of atherosclerosis.4 Several studies have reported an association between elevated serum cholesterol levels and atherosclerosis of vein grafts as determined at autopsy.5 6 Recently, plasma low-density lipoprotein (LDL) levels have been shown to be elevated and plasma high-density lipoprotein (HDL) levels reduced in patients with stenotic grafts more than 10 years after From the

Relationship between Plasma Homocysteine Levels and Saphenous Vein Graft Disease after Coronary Artery Bypass Grafts.

“…1,2) Many risk factors responsible for SVG disease, including smoking, elevated levels of cholesterol, diabetes and longer intervals after CABG, have been identified. [3][4][5] In this study, we have demonstrated for the first time that homocysteine levels were significantly higher in the vein graft disease group than in the no-vein graft disease group, indicating that elevated levels of plasma homocysteine are an independent risk for SVG disease.…”

“…[3][4][5]36,37) In the present study, in addition to high levels of homocysteine, low levels of high-density lipoprotein cholesterol and longer intervals between bypass surgery and coronary angiography were considered to be risk factors for SVG disease. In contrast, low-density lipoprotein cholesterol has no significant relation with SVG disease in this study because levels of low-density lipoprotein cholesterol were controlled by lipid lowering drugs in 64% of all subjects.…”

“…1,2) Several factors including smoking, high cholesterol levels, and diabetes mellitus have been identified as risk factors for SVG disease. [3][4][5] Recently, elevated levels of homocysteine have been shown to be an independent risk factor for cardiovascular disease. [6][7][8][9][10][11][12][13][14][15][16] Patients with homocystinuria, causing extremely high levels of homocysteine in the blood and urine due to homozygosity for cystathionine synthase deficiency, develop premature vascular disease in early adolescence.…”

Coronary vein graft disease: Pathogenesis and prevention

“…In a study of patients with a history of CABG undergoing coronary angiography, Hoff et al (28) found a linear correlation between degree of graft stenosis and the serum lipoprotein(a) level. At approximately the same time, the Cholesterol Lowering Atherosclerosis Study (CLAS) (29,30) assessed the benefits of lowering LDL and raising HDL on angiographic disease progression in vein grafts as well as native coronary arteries.…”

Metabolic and anthropometric determinants of serum Lp(a) concentrations and Apo(a) polymorphism in a healthy Arab population

“…4 Genetic factors are the principal determinants of plasma Lp(a) concentrations 5,6 via differences in apolipoprotein(a) polymorphisms between individuals and races. Other factors such as diet, exercise, body mass, gender 7 and probably insulin levels 8 have, however, been shown to be important determinants of Lp(a) concentrations as well; although probably not quantitatively as important as the genetic determinant.…”