- Poster presentation
Associations between LDL/HDL-cholesterol ratio and thoracic and abdominal aortic atherosclerosis assessed by MRI
Journal of Cardiovascular Magnetic Resonancevolume 14, Article number: P72 (2012)
Recently, the LDL/HDL-cholesterol ratio has become recognized as a stronger risk predictor of cardiovascular diseases than each lipid parameter. However, the association between LDL/HDL-cholesterol ratio and aortic atherosclerosis has not been elucidated yet. Using MRI, we investigated the associations between thoracic and abdominal aortic atherosclerosis and LDL/HDL-cholesterol ratio as well as LDL- and HDL-cholesterol levels.
Aortic MRI was performed on Signa 1.5T Cvi using a phased-array body coil in 159 patients at high-risk for CAD. However, since statins affect LDL- and HDL-cholesterol levels, 64 patients who were taking statin were excluded from this study. Transverse PDW and T2W images of thoracic descending and abdominal aortas were obtained using an ECG-gated, double-inversion-recovery FSE sequence: TR=2 RR intervals, TE=10ms (PDW) and 60ms (T2W), 20-cm FOV, 4-mm slice thickness, 8-mm inter-slice gap, 256x256 acquisition matrix, and 32 echo-train. For each patient, 9 slices of thoracic aorta and 9 slices of abdominal aorta were obtained at 12-mm intervals, which each covered about 10-cm portion of thoracic aorta below the arch and 10-cm portion of abdominal aorta above the bifurcation of iliac artery. Plaque extent in each slice was scored 0 to 4 points by the percentage of luminal surface involved by plaque. The severity of aortic atherosclerosis was represented as sum of scores (plaque score).
Among the 95 study patients without statin (age 63±9 years), thoracic and abdominal aortic plaques were found in 60 (63%) and 84 (88%) patients, respectively. The severities of both thoracic and abdominal aortic atherosclerosis correlated with age and blood pressures. Regarding lipid parameters, the severity of thoracic aortic atherosclerosis correlated with LDL-cholesterol (r=0.30) and HDL-cholesterol (r=-0.26) levels (P<0.01) and much better with LDL/HDL-cholesterol ratio (r=0.36, P<0.001). However, the severity of abdominal aortic atherosclerosis correlated with only HDL-cholesterol level (r=-0.29, P<0.005) but not with LDL-cholesterol or LDL/HDL-cholesterol ratio (P=NS). In multiple linear regression analysis, age and LDL/HDL-cholesterol ratio were the independent factors associated with thoracic aortic atherosclerosis, whereas age and HDL-cholesterol level as well as HbA1c and smoking were the factors associated with abdominal aortic atherosclerosis.
Among lipid parameters, the LDL/HDL-cholesterol ratio was found to be a stronger factor associated with thoracic aortic atherosclerosis than either LDL-cholesterol or HDL-cholesterol levels, whereas abdominal aortic atherosclerosis was associated with only HDL-cholesterol levels. Our results suggest that thoracic and abdominal aortas may have different susceptibilities to atherosclerotic risk factors. MRI is a very useful tool for non-invasively evaluating atherosclerosis in both thoracic and abdominal aortas.
Our study had no funding.