RESUMO
Lipoprotein (a) [Lp(a)] is an independent genetically determined marker of coronary artery disease. It is present in the atheromatous plaque with a molecular structure similar to that of plasminogen. Its role in postangioplasty restenosis is a possibility but is controversial. A population of 103 coronary patients underwent angioplasty with control coronary angiography before the 6th month; there were 53 good results and 50 cases of restenosis. The Lp(a) was measured by immunonephelemetry (threshold value of 250 mg/l). A subgroup with Lp(a) concentrations > 250 mg/l was identified. The average concentrations of Lp(a) in the two groups without restenosis (368 +/- 350 mg/l) and with restenosis (418 +/- 434 mg/l) were not statisticaly different (p = 0.2). When cases with Lp(a) > 250 mg/l were considered alone, the tendency to higher average concentrations of Lp(a) in the group with restenosis (777 +/- 424 mg/l) compared with the group without restenosis (656 +/- 340 mg/l) was more clear-cut but did not achieve statistical significance (p = 0.08). The individual scatter of Lp(a) being very wide (83 to 1,450 mg/l in the group without restenosis and 90 to 1,740 mg/l in the group with restenosis), it is impossible to predict restenosis from this parameter in a given individual. No correlations were observed between the different lipid fractions and restenosis. The extension of the lesions and the angioplasty site did not correlate with restenosis in this study. The authors conclude: 1) that the Lp(a) concentration has no individual predictive value for restenosis; 2) individuals with Lp(a) concentrations > 250 mg/l have an increased risk of restenosis (NS); 3) these results confirm other recent publications; and 4) further research into the isoforms of Lp(a) in each group could provide interesting data.
