Shigeru Watanabe

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.

New indices of ischemic heart disease and aging: studies on the serum levels of soluble intercellular adhesion molecule-1 (ICAM-1) and soluble vascular cell adhesion molecule-1 (VCAM-1) in patients with hypercholesterolemia and ischemic heart disease

It is known that the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on the surface of vascular endothelial cells is closely related to the formation of early atherosclerotic lesions. In this study, serum soluble ICAM-1(sICAM-1) and soluble VCAM-1(sVCAM-1) were determined by sandwich ELISA both in normal healthy individuals (n = 114) and in patients with hypercholesterolemia (HC, n = 112) or ischemic heart disease (IHD, n = 38) to clarify the significance of the soluble forms of the adhesion molecules in the development of atherosclerotic diseases. IHD patients, not HC patients, showed significant elevation of sICAM-1, but not of sVCAM-1, compared with controls in age and sex-matched subjects. In addition, multiple linear regression analysis showed that sICAM-1 was correlated only to the presence of IHD but not to age and lipids. Multiple logistic regression analysis revealed that sICAM-1 was the most powerful independent predictor of the presence of IHD. On the other hand, sVCAM-1, not sICAM-1, was positively correlated to age. Multiple linear regression analysis showed that age was the most powerful independent predictor of the level of sVCAM-1. These data suggest that sICAM-1 and sVCAM-1 are useful as indices of clinical manifestations of atherosclerosis and aging, respectively.

The usefulness of x-ray computed tomography for the diagnosis of myocardial infarction.

Conventional and enhanced computed tomographic (CT) examinations were performed in 103 patients with myocardial infarction for evaluation of the diagnostic usefulness of CT. After intravenous bolus injection of contrast material, an initial filling defect and late enhancement of the infarcted myocardium appeared on the cardiac CT images. These two findings were direct evidence of myocardial infarction; the former was found mostly in the patient with recent myocardial infarctions, and the latter was recognized both in those with recent and those with remote infarctions. Wall thinning at the site of infarction was found by enhanced CT mostly in patients with anteroseptal or extensive anterior infarctions, and was rarely found in patients with inferoposterior infarctions. Left ventricular aneurysms and ventricular thrombi were found by enhanced CT in 39 and 23 of the 103 subjects, respectively, and the sensitivity of CT in detecting intracardiac thrombi was higher than that of two-dimensional echocardiography. Calcification of the myocardium and pericardial effusion associated with myocardial infarction were also detected by conventional nonenhanced CT. Thus, cardiac CT was found to be a useful test in evaluating patients with myocardial infarction.

Coronary artery calcification detected by CT: clinical significance and angiographic correlates.

Cardiac computed tomography (CT) to detect coronary calcification was performed on 161 patients undergoing coronary angiography for proven or suspected coronary artery disease. Among 108 patients in whom coronary calci fications was identified, 90% had significant coronary stenosis angiographically (>75% stenosis), and 80% of 121 patients with significant coronary stenosis showed calcification by CT. The relationship between the calcification site and the significance in stenosis of each vessel was determined. Calcification was present in 133 arteries among 205 stenotic coronary arteries (sensitivity = 65%) as compared with 59 of 439 entire arteries with normal coronary angiograms (specificity = 87%). In the younger age group the sensitivity of calcification for stenosis of each coronary artery was lower and the specificity and predictive value were generally higher than those in the elderly group. These results demonstrate that CT is a valuable procedure for detecting coronary arterial disease, since this examination is easy to conduct, noninvasive, and widely applicable for screeening a large population.

Coronary artery calcification detected by a mobile helical computed tomography unit and future cardiovascular death: 4-year follow-up of 6120 asymptomatic Japanese

In the present study, we performed a prospective follow-up study in a population which underwent chest computed tomography (CT) screening. A total of 6u2009120 participants underwent a chest CT medical examination for lung cancer and tuberculosis in Nagano Prefecture, Japan, between 1996 and 1997. Computed tomography scanning was performed from the apex of the lung to the diaphragm at a tube voltage of 120u2009kV and a tube current of 50u2009mA. We measured the CT density of the coronary arteries in 5–7 slices where coronary arteries were detected. The CT density threshold for determining coronary artery calcification (CAC) was above +110 HU. In 2000, we investigated the number of deaths due to cardiac and noncardiac disease among the participants. Of the 6120 participants, 14 died of cardiac disease (9, myocardial infarction; 4, heart failure; and 1, angina pectoris) and 64 died of other diseases. Coronary artery calcification was detected in 10 of the patients who died of cardiac disease, and in 31 of those who died of other diseases. The prevalence of CAC was higher in the former than in the latter (71.4% vs 48.4%, P = 0.084). The relative risk of CAC for cardiac death was 2.66 (95% confidence interval: 0.76, 9.37). The findings of this study suggested that CAC detected in a mass chest CT screening by a mobile helical CT unit was predictive of future cardiovascular death.

Measurement of aortic diameters and detection of asymptomatic aortic aneurysms in a mass screening program using a mobile helical computed tomography unit.

Abstract In a mass chest computed tomography (CT) screening using a mobile helical CT unit, we measured the aortic diameter at three segments to confirm standard values and also attempted to detect any asymptomatic aortic aneurysms. The population screened in the present study consisted of 6 971 subjects (3 847 men and 3 124 women, mean age 60.3 ± 12.1 years). They underwent a plain chest CT to screen for lung cancer and tuberculosis. The diameters of the ascending and descending aorta were measured at the level of the pulmonary artery bifurcation. The abdominal aorta was measured at the level of the celiac bifurcation, and the mean values for each measurement were calculated. In addition, we attempted to determine whether any correlation exists among aortic diameter, age, and indices of body size and investigated the frequency of asymptomatic aortic aneurysms among the general population. The mean aortic diameter of all three segments was significantly larger in men than in women and increased with age. It also correlated significantly with indices of body size (P < 0.01). A total of 11 subjects (0.16%) had asymptomatic aortic aneurysms (3 ascending, 4 descending, and 4 thoracoabdominal). The aortic diameter in each individual case was greater than the mean aortic diameter +3 standard deviations in each age group. Chest CT screening for lung cancer can thus detect asymptomatic aneurysms through simultaneous aortic measurement.

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.

ECG synchronized computed tomography in clinical evaluation of total and regional cardiac motion: Comparison of postmyocardial infarction to normal hearts by rapid sequential imaging

Computed tomograph (CT) of the heart was performed using the JEOL Dynamic Scanner, which provides CT cardiac images with minimal radiation and within a short period of time. ECG-synchronized CT was undertaken at various phases of the cardiac cycle every 0.04 second. Approximately 30 minutes of scanning was necessary to obtain a series of CT images of one complete cardiac cycle. In contract to 24 normal subjects, 38 patients with recent or remote myocardial infarction (MI) demonstrated hypokinetic, akinetic, or paradoxical movement of the ventricular segment corresponding to the MI sites predicted by ECG. The sequential cardiac area curve was useful in evaluating instantaneous changes of cardiac dimension, extent of ventricular contraction, and regional dyssynergy. ECG-synchronized CT studies using Somatom contrast dye enhancement in selected patients allowed sequential assessment of left ventricular cavity size and wall motion.

A case report of intravenous leiomyomatosis extending into the heart.

Abstract The patient was a 47-year-old woman who underwent total hysterectomy for uterine leiomyoma in 1994. Two years later, intracaval and intravenous tumors were found by ultrasonic cardiography, magnetic resonance imaging, enhanced chest computed tomography, and venography. The patient underwent total removal of these tumors. Pathological findings indicated that these tumors were leiomyomas. After comparing the present findings with those of similar cases in the literature, we concluded that our patient had intravenous leiomyomatosis extending into the heart.