LDL/HDL cholesterol ratio linked to lipid-rich coronary plaque
MedWire News: A high ratio of low-density lipoprotein (LDL) to high-density lipoprotein (HDL) cholesterol may help to identify chronic coronary artery disease (CAD) patients who have unstable plaques, research suggests.
An elevated LDL/HDL cholesterol ratio “may be a positive predictor for coronary-rich plaque and plaque vulnerability,” say Tomonori Itoh (Iwate Medical University, Morioka, Japan) and co-workers.
The findings tie in with those from an analysis of the Framingham study, which showed that the LDL/HDL cholesterol ratio is a strong predictor of coronary events, they add.
The researchers performed integrated backscatter intravascular ultrasound (IVUS) and conventional IVUS in 24 patients with acute coronary syndromes (ACS) and 68 with chronic CAD.
They found that the average lipid pool area of target lesions was significantly larger in ACS patients than in those with chronic CAD, at 7.0 versus 5.1 mm2. Also, the ratio of the area of lipid pool to that of the rest of the lesion was nonsignificantly higher in ACS than chronic CAD patients, at 1.4 versus 1.1.
The ratio of LDL to HDL cholesterol was significantly higher in ACS than chronic CAD patients, at 2.3 versus 1.99. It correlated with the ratio of the lipid to non-lipid lesional areas in patients with chronic CAD, but not in those with ACS.
“This may be due to post-admission changes in blood lipid profile that usually occur in patients with ACS,” say Itoh et al. “It is well known that when blood samples are obtained after onset of ACS, serum LDL cholesterol levels are likely to be as much as 30–40% lower than the actual baseline level.”
In the chronic CAD group, a LDL/HDL cholesterol ratio of 2.1 or above predicted a ratio of lipid to non-lipid lesional area in the 90th percentile with a sensitivity of 83% and a specificity of 71%. It was able to distinguish between patients with and without a high ratio of lipid to non-lipid lesional area with 79% accuracy, which was notably better than with LDL cholesterol or HDL cholesterol individually.
This shows that the LDL/HDL cholesterol ratio “is a highly specific and sensitive predictor of abnormal lipid-rich plaque in patients with chronic CAD,” concludes the team in the Circulation Journal.
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By Eleanor McDermid