Elevated levels of lipoprotein (a) in patients suffering from myocardial infarction with carotid atherosclerotic lesions

The aim of the present study was to evaluate metabolic, coagulation and fib rinolytic parameters in 45 patients [31 men, 14 women, aged 56.5 +/- 3.5 ye ars (mean +/- SD)] who had suffered myocardial infarction more than 6 month s earlier, with or without carotid atherosclerotic lesions. After the extra cranial carotid arteries had been evaluated using a B-mode Duplex scanning system, patients were subdivided into two groups: group 1 (n = 20) with car otid plaques or measurable intima-media thickness; and group 2 (n = 25) wit hout carotid plaques or measurable intima-media thickness. Twenty-two age- and sex-matched subjects were recruited as controls (group 3). Groups 1 and 2 displayed significantly higher levels of total cholesterol, apolipoprote in B, human autoantibodies against oxidised low-density lipoprotein and the c fraction of the third component system, and significantly lower levels o f high-density lipoprotein cholesterol and apolipoprotein A1 than group 3. However, serum levels of triglyceride and lipoprotein (a) were significantl y higher in group 1 than in the control group. Moreover, groups 1 and 2 dis played significantly higher levels of factor VII, fibrinogen, fragment 1+2, thrombin-antithrombin complex and plasminogen activator inhibitor after ve nous occlusion, and significantly lower levels of tissue-type plasminogen a ctivator after venous occlusion than group 3. Significantly higher levels o f tissue-type plasminogen activator and plasminogen activator inhibitor bef ore venous occlusion were observed in groups 1 and 2 and significantly lowe r levels of antithrombin III, protein C and protein S were observed in grou p 1 compared with the controls. Patients were also analysed according to le vels of lipoprotein (a). The lowest levels of tissue-type plasminogen activ ator after venous occlusion and the highest levels fragment 1+2, the c frac tion of the third component system, and plasminogen activator inhibitor aft er venous occlusion were observed in patients with the highest levels of li poprotein (a). Our data demonstrate an activation of coagulation and defici ent fibrinolysis in survivors of myocardial infarction, particularly in tho se with associated carotid atherosclerotic lesions. We speculate that this thrombophilic state may play a key role in the pathogenesis of atherosclero tic vascular disease and thromboembolic complications. Blood Coag Fibrinol 10:331-339 (C) 1999 Lippincott Williams & Wilkins.