Lipoprotein(a) and coronary thrombosis and restenosis after stent placement

OBJECTIVES The objective of this prospective study was to evaluate the rela tion between high lipoprotein(a) levels and thrombotic and restenotic event s after coronary stent implantation. BACKGROUND Lipoprotein(a) may promote atherogenesis, coronary thrombosis an d restenosis after balloon angioplasty, but the clinical significance remai ns unclear. METHODS The study included 2,223 consecutive patients with successful coron ary stent placement. According to the serum level of lipoprotein(a), patien ts were divided in two groups: 457 patients of the highest quintile formed the high lipoprotein(a) group, and 1,766 patients of the lower four quintil es formed the low lipoprotein(a) group. Primary end points were the inciden ce of angiographic restenosis at six months and the event free survival at one year. Secondary end point was the incidence of angiographic stent occlu sion. RESULTS Early stent occlusion occurred in four of the 457 patients (0.9%) w ith high and 37 of the 1,766 patients (2.1%) with low lipoprotein(a) levels , odds ratio of 0.41 (95% confidence interval, 0.15 to 1.16). Angiographic restenosis occurred in 173 of the 523 lesions (33.2%) in the high lipoprote in(a) group and 636 of the 1,943 lesions (32.7%) in the low lipoprotein(a) group, odds ratio of 1.02 (0.83 to 1.25). The probability of event-free sur vival was 73.0% in the high lipoprotein(a) group and 74.8% in the low lipop rotein(a) group (p = 0.45). On the basis of the findings in the low lipopro tein(a) group, the power of this study to detect a 25% increase in the inci dence of restenosis and adverse events in the group with elevated lipoprote in(a) was 90% and 75%, respectively. CONCLUSION Elevated lipoprotein(a) levels did not influence the one-year cl inical and angiographic outcome after stent placement. Thrombotic events an d measures of restenosis were not adversely affected by the presence of hig h lipoprotein(a) levels. (J Am Coil Cardiol 1999;33: 1005-12) (C) 1999 by t he American College of Cardiology.