Association of lipoprotein(a) concentration and apo(a) isoform size with restenosis after percutaneous transluminal coronary angioplasty

Abstract

Lp(a) is a unique class of lipoprotein particles that exhibits a considerable size heterogeneity resulting from the size polymorphism of apo(a), its unique protein component. An elevated level of Lp(a) in plasma has been proposed to be a risk factor for premature development of coronary artery disease. To evaluate the relationship between Lp(a) concentration and apo(a) isoform size with restenosis after percutaneous transluminal coronary angioplasty, Lp(a) levels and apo(a) phenotypes were determined in 204 patients who underwent a successful coronary angioplasty procedure and stent implantation. The patients were followed with clinical examinations and exercise tests at 1, 3, and 6 months, and a control coronary angiography was performed after 6 months to evaluate restenosis. Lp(a) levels were determined with an ELISA that is insensitive to the size heterogeneity of Lp(a), and the apo(a) isoforms were determined by a high-resolution agarose gel electrophoresis method followed by immunoblotting with a specific monoclonal antibody. Of the 146 patients who underwent angiographic evaluation, 57 (39%) had restenosis, whereas 89 (61%) did not. Lp(a) levels and the distribution of the expressed apo(a) phenotypes were compared in these two groups of patients. Although the mean and median Lp(a) levels were higher in the restenosed group, the difference was not statistically significant. However, a significant difference in Lp(a) values was found in women (P=0.043), even though, because of the small number of women in the study (n=35), no sound conclusions can be reached on the predictive role of Lp(a) in restenosis. There also was no difference in the distribution of apo(a) phenotypes between the two groups. Because of their wide distribution, Lp(a) values and apo(a) isoforms do not seem to be a useful indicator of risk of restenosis after percutaneous transluminal coronary angioplasty in our study cohort.

Risk factors of thromboembolism in nonvalvular atrial fibrillation patients with low CHA2DS2-VASc score

“…These could make the coagulation function prevail and promote thrombosis. [29,30] Furthermore, Lp(a) could bind heparin and heparan sulfate, which closed the substrate, causing its inhibition of thrombosis inactivation. [31] It suggested that elevated Lp(a) could facilitate coagulation-fibrinolytic system during thrombosis.…”

Present status of outcome prediction of invasive coronary treatment by using genetic markers

“…The genes coding for apolipoprotein A (APOA, X02162) or apolipoprotein E (APOE, K00396) contain several sequence variations that were analyzed with respect to their possible involvement in restenosis after PCI [Samani et al, 1996;Sirikci et al, 2000;Gazzaruso et al, 2003a, b;Damaraju et al, 1995;Van Bockxmeer et al, 1994]. Many [Samani et al, 1996;Sirikci et al, 2000;Gazzaruso et al, 2003a, b] albeit not all studies Van Bockxmeer et al, 1994] failed to demonstrate an association between a specific sequence variation and restenosis. A more recent study did not find an association of the c.388T4C (p.Cys130Arg), c.-1046T4G, or c.-714C4G sequence variations in the APOE gene and the risk of in-stent restenosis.…”