Abstract 837: High Remnant Lipoprotein Levels Adversely Affect Outcome in Patients With Acute Coronary Syndromes and Metabolic Syndrome
Metabolic syndrome has a negative impact on prognosis in patients with acute coronary syndromes (ACS). Triglyceride-rich lipoproteins are a risk factor of cardiovascular diseases in metabolic syndrome. We have previously shown that remnant lipoproteins, triglyceride-rich lipoproteins, have strong proinflammatory and proatherothrombogenic properties. Thus, this study tested the hypothesis that remnant lipoproteinemia may worsen outcomes in ACS patients with metabolic syndrome.
Methods: A prospective study was performed in 320 consecutive ACS patients with metabolic syndrome meeting ATPIII criteria, who were enrolled on day 5 after the onset of ACS. Fasting serum levels of remnant lipoproteins (remnant-like lipoprotein particles cholesterol; RLP-C) on day 5 after ACS were measured by an immunoseparation method. Adverse events, a composite of cardiac death, nonfatal myocardial infarction, or recurrent unstable myocardial ischemia leading to unplanned revascularization therapy, were assessed during follow-up periods of 30 days and 1 year after ACS.
Results: Events rates were higher in patients with than without higher RLP-C levels (≥5.5 mg/dL, 50th percentile of the distribution) during both short- and long-term follow-up (30 days post-ACS, 8% [13/160 patients with higher RLP-C levels] vs. 3% [5/160 patients with lower RLP-C levels], p<0.05; 1 year post-ACS, 16%  vs. 6% , p<0.01). In a multivariate Cox proportional hazard analysis, higher RLP-C levels were a significant predictor of future cardiac events during 30 days and 1 year that was independent of enrollment levels of glucose, LDL-C, non-HDL-C, and triglyceride (30 days outcome; hazard ratio 1.4, 95% CI 1.2–3.9, p=0.02. 1 year outcome; hazard ratio 2.4, 95% CI 1.2–5.0, p<0.01). High RLP-C levels were significantly associated with high levels of C-reactive protein and intimal thickening of carotid arteries at enrollment (r=0.31 and 0.28, respectively, both p<0.01).
Conclusions: High remnant lipoprotein levels adversely affect outcomes in patients with ACS and metabolic syndrome. The proinflammatory and proatherogenic effects of remnant lipoprotein may contribute to coronary plaque vulnerability in patients with ACS and metabolic syndrome.