MedWire News: Plasma lipid profiling may be useful for the identification of unstable atherosclerotic plaques in patients with coronary artery disease (CAD), study findings suggest.
The Australian researchers found that classification models incorportating both lipids and traditional risk factors provided improved classification of unstable CAD from stable CAD compared with models containing only traditional risk factors, such as smoking status, body mass index, cholesterol levels, and blood pressure.
Risk assessment for CAD is currently performed by the evaluation of traditional risk factors; by direct measures of arterial structural changes associated with atherosclerosis, such as carotid intima medial thickness and the coronary artery calcification score; or by testing for myocardial ischemia using stress testing.
However, "current screening is limited by the predictive power of available tests, the high cost of these tests, or a combination of both," comment the researchers. "Furthermore, the ability of these tests to subclassifiy patients with CAD as having stable or unstable disease has been limited."
Peter Meikle (Baker IDI Heart and Diabetes Institute, Melbourne, Victoria) and colleagues therefore evaluated the potential of lipid profiles for assessing the risk for future plaque instability in patients with CAD. Plasma lipid profiles, containing 305 lipids, were measured in 220 individuals. Of these, 60 had stable angina, 80 had unstable coronary syndrome, and 80 were healthy (no CAD) controls.
The researchers developed logistic regression-based classification models, which were repeated 1000 times, to assess the relative contribution of lipids and traditional risk factors to the differentiation of unstable from stable CAD.
As reported in the journal Arteriosclerosis, Thrombosis, and Vascular Biology, models using a combination of lipids and traditional risk factors to distinguish between patients with unstable and stable CAD provided a maximum C-statistic of 0.869. In comparison, models created with the traditional risk factors alone achieved a maximum C-statistic of 0.796.
Of note, the model that combined lipids and risk factors had the highest accuracy, at 78.0%, compared with risk factors alone (70.2%) or lipids alone (73.3%).
"These findings indicate that plasma lipid profiling may have diagnostic and prognostic potential for the identification of individuals at risk for unstable coronary syndromes," conclude Meikle et al.
"Further prospective studies are now required to validate the predictive ability of this approach to the identification of the vulnerable patient," they add.
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
Free abstract
