Junichiro Takasu

Pericardial fat accumulation in men as a risk factor for coronary artery disease

An increment of abdominal visceral fat accumulation has been reported to be a coronary risk factor. We determined the predictive power of pericardial fat (Pfat) accumulation as intra-thoracic visceral fat, in the diagnosis of coronary artery disease (CAD). Among 251 (181 non-obese [body mass index<25], 70 obese [body mass index> or =25]) Japanese male patients who underwent computed tomography (CT), 128 (90 non-obese, 38 obese) patients were suffering from CAD. Pfat volume was determined by the sum of cross-sectional images 1cm thick from the atrial appendage to the apex over the diaphragm. Abdominal visceral fat (Vfat) and subcutaneous fat (Sfat) areas were measured by a single scan at the L4-L5 region. Pfat was most associated with Vfat in body fat distribution. In non-obese patients, Pfat was most associated with CAD among the various risk factors including body fat distribution. Moreover, Pfat was the strongest independent variable for the severity of CAD, determined by coronary angiogram. This result showed that pericardial fat accumulation was a stronger coronary risk factor than the other body fat distributions in non-obese men.

Evaluation of morphological changes of the atherosclerotic aorta by enhanced computed tomography

Enhanced and non-enhanced computed tomography (CT) were performed in 405 subjects (222 men; 183 women; mean age 57 years). Intimal atherosclerotic changes of the aorta were quantified by enhanced CT, revealing the atheromatous intima to be projecting and thick-walled, while non-enhanced CT demonstrated aortic calcification. We measured the degree of aortic intimal changes at various segments of the aorta. In 224 cases, CT was performed from the aortic root to the bifurcation of the abdominal aorta. Intimal changes were found predominantly at the aortic arch, the middle descending thoracic and the infrarenal abdominal aorta. As for the intimal changes, aortic calcification and aortic pulse wave velocity were significant atherosclerotic characteristics. The aortic diameter did not show a significant association with intimal change. Among the various atherosclerotic risk factors, intimal change was significantly associated with age, systolic blood pressure, serum total cholesterol and diabetes mellitus, whereas gender, diastolic blood pressure, relative weight and cigarette use were not significantly related. For coronary artery disease and arteriosclerosis obliterans, aortic intimal changes constituted a significant atherosclerotic feature. In cerebrovascular disease, however, aortic intimal change did not play a significant role.

Progression and regression of atherosclerotic findings in the descending thoracic aorta detected by enhanced computed tomography

Reports evaluating the progression and regression of atherosclerosis by non-invasive procedure are still limited. We investigated the progression and regression of atherosclerotic intimal thickening of the descending thoracic aorta non-invasively measured by enhanced computed tomography in 83 patients (average age 51.0 years) at the beginning and end of a 2.5 year period. The patients were not taking anti-hypertensive, lipid-lowering or hypoglycemic drugs and therefore we consider them as a natural history cohort. At entry, the extent of aortic intimal thickening was 35.2% of the circumference of the cross-section of the wall, which increased to 39.7% after 2.5 years. Spontaneous progression was associated directly with age, elevated levels of total cholesterol, LDL-cholesterol, LDL/HDL cholesterol ratio, diastolic blood pressure, and inversely to HDL-cholesterol. There was little correlation with triglycerides, systolic blood pressure, fasting glucose or body mass index. In 65 of the patients, aortic atherosclerosis progressed, while in 9 patients it remained unchanged, and in a further 9 it regressed. The levels of lipid variables, apart from HDL-cholesterol, and diastolic blood pressure in the patients with spontaneous progression were significantly higher than in the unchanged and spontaneous regression. Thus, this study verified the natural history of aortic atherosclerosis non-invasively measured by enhanced CT.