Lipoprotein(a) concentrations are increased in patients with myocardial infarction and angiographically normal coronary arteries.

Abstract

It is generally accepted that Lp(a) is an independent risk factor of cardiovascular diseases. Since the apolipoprotein component of Lp(a) shows some homologies to plasminogen, it is, however, unclear as to whether the pathological effect is due to the role played by the lipoprotein in lipid metabolism or in the fibrinolytic system. We compared two groups of patients with myocardial infarction, with and without angiographically documented coronary artery disease. In the latter group, imbalances in the clotting system are very likely, while members of the former group may also display disturbances of lipid metabolism. The results show that the two groups display differences in lipid metabolism, whereas they have similar patterns of thrombogenicity indices and Lp(a) values. This study seems to support the hypothesis that Lp(a) does play a role in the fibrinolytic system, since even those myocardial infarctions without obstructive coronary artery disease have a high frequency of Lp(a) concentrations above 300 mg/l, i.e. similar to the situation found in the myocardial infarctions with angiographically documented coronary artery disease. Whether the high Lp(a) concentrations in the two groups are related to an impaired fibrinolysis will be the subject of further investigation.