Thrombolysis with tissue plasminogen activator enhances serum lipoprotein(a) levels compared to streptokinase and conservative treatment in patients with acute myocardial infarction

Lp(a) may interfere with thrombosis and thrombolysis. We followed Lp(a) levels in 20 patients with acute myocardial infarction randomized to receive streptokinase (SK, n=10) or tissue-plasminogen activator (t-PA, n=10). The results were compared to those obtained with five patients treated conservatively. Baseline characteristics were equal in the study groups. Lp(a) levels increased significantly, (22.1%) during t-PA infusion (P<0.005 t-PA vs SK, P<0.005 t-PA vs conservative treatment), but they remained unchanged during SK infusion and conservative treatment. In all three groups, a more prominent increase in serum Lp(a) levels, (51.8%, 24.4%, and 36.8% for the t-PA, SK, and conservative treatment groups, respectively), was observed 3 days after the admission to the hospital, probably reflecting an acute phase reaction. Although the size of the study is relatively small, the suggested linkage between Lp(a) and thrombolytic treatment with t-PA may be of interest, and the mechanisms behind it need to be elucidated. The alterations in Lp(a) levels may be involved in the complex interactions between thrombolytic agents, thrombus, clotting cascade, and endothelium affecting thrombolysis and reocclusion.