Abstract 8789: Elevated Serum Lipoprotein(a) Level as Predictor of Coronary Plaque Vulnerability in Men Using 64-Multidetector Computed Tomography
Background: Lipoprotein(a) [Lp(a)] is characterized by its specific apolipoprotein(a). It has been implicated in the regulation of the expression of plasminogen activator inhibitor-1 and shown to attenuate plasminogen binding to platelets. Thus, Lp(a) may provide a link between the pathogenic process of thrombosis and atherosclerosis, and may be associated with the development of vulnerable plaque prone to rupture with subsequent pathogenesis of acute coronary syndrome (ACS). We investigated whether the elevated serum Lp(a) level is related to coronary plaque vulnerability.
Methods: We enrolled 216 consecutive patients (age: 67 ± 11 years, 63% men) with suspected coronary artery disease referred for 64-multidetector computed tomography (CT). Serum Lp(a) was measured by an immunoturbidimetric assay within 1 week after CT angiography. Coronary arteries were assessed using a 17-segment model for the presence and extent of non-calcified plaque (NCP). Furthermore, vulnerable plaque (VP) was defined as if NCP had three characteristics including low-density (minimum plaque CT density <39 HU), positive remodeling (remodeling index >1.05), and adjacent spotty calcification.
Results: The prevalence of detectable NCP was 75%. The serum Lp(a) level ranged from 0.6 to 218.3 mg/dl (median 18.1 mg/dl). The serum median level of Lp(a) was significantly higher in patients with VP than those without (n = 51; 25.6 mg/dl vs. n = 165; 16.6 mg/dl, p = 0.018). In a univariate analysis, log-transformed Lp(a) value was significantly correlated with the presence of NCP (OR [95%CI] 1.56 [1.06–2.29], p = 0.025) and VP (1.76 [1.18–2.62], p = 0.006) in men, but not in women. Therefore, a multivariate analysis was performed in men adjusted with age and conventional risk factors. Log-transformed Lp(a) value was independently related to the presence NCP (1.61 [1.02–2.52], p = 0.039) and VP (1.91 [1.23–2.94], p = 0.004) in men. Furthermore, serum Lp(a) level is positively correlated with numbers of NCP (β-estimate [95%CI] 0.62 [0.27–0.96], p = 0.001) and VP (0.23 [0.08–0.39], p = 0.004).
Conclusions: The elevated serum Lp(a) level is associated with the existence of vulnerable non-calcified plaques in men, thereby serving as an indicator to identify patients prone to occurring ACS.
- © 2010 by American Heart Association, Inc.