Lipoprotein levels may be important in determining the type of detectable coronary plaque found in patients with newly diagnosed coronary artery disease (CAD), researchers claim.
They found that low-density lipoprotein (LDL) cholesterol levels were associated with increased levels of both noncalcified plaque and a mixture of calcified and noncalcified plaque.
Furthermore, LDL cholesterol was the sole variable among traditional clinical coronary risk factors to independently predict the relative predominance of each plaque type.
Previous studies suggest that plaques containing both calcified and noncalcified components may be at greatest risk for eventual rupture, say the US researchers.
They examined the relationship between lipoproteins, plaque composition, and total plaque burden in 823 patients without previously diagnosed CAD but with visible coronary plaque on computed tomographic angiography.
Of these individuals, 34% were asymptomatic and 52% were receiving statin therapy.
Contrast-enhanced, electrocardiographic-gated computed tomography was used to obtain segmental counts for calcified plaque, noncalcified plaque, mixed plaque, and total plaque.
Age, male gender, diabetes, smoking, and statin therapy were all significantly associated with calcified plaque count, the researchers report in the American Journal of Cardiology.
LDL cholesterol was significantly associated with both mixed plaque and noncalcified plaque count.
In addition, LDL cholesterol was also the only variable to significantly relate to the ratios of calcified to total plaque, mixed to total plaque, and noncalcified to total plaque.
This included a strong inverse association between calcified and total plaque, and a positive association between mixed and total plaque.
When non–high-density lipoprotein (non-HDL) cholesterol was used in place of LDL cholesterol similar results were obtained.
Victor Cheng (Cedars-Sinai Medical Center, Los Angeles, California) and colleagues say: “The results from our work suggest that LDL cholesterol and atherogenic non-HDL cholesterol play important roles in the development of mixed plaque and noncalcified plaque.”