This histopathologic study confirms an intimate relation between whole heart, coronary artery, and segmental coronary atherosclerotic plaque area and EBCT coronary calcium area but suggests that there is a threshold value for plaque area below which coronary calcium is either absent or not detectable by this methodology.

These studies were undertaken to compare dual-energy x-ray absorptiometry (DXA) and computed tomography (CT) measurements of abdominal fat and to determine whether anthropometry could be combined with DXA to predict intraabdominal (visceral) fat mass in humans. Twenty-one volunteers underwent abdominal CT scans, DXA, and anthropometry. DXA- and CT-measured total abdominal fat were similar (8448 +/- 5005 and 8066 +/- 5354 mL, respectively; NS) and were highly correlated (r = 0.985, P < 0.001). The combination of anthropometry and DXA was a suboptimal predictor of CT-measured intraabdominal fat (r = 0.61, P < 0.05); however, the combination of a single CT slice (to assess the ratio of intraabdominal to total abdominal adipose tissue) and DXA-measured abdominal fat was an excellent predictor of CT-measured intraabdominal fat (r = 0.98, P < 0.001). We conclude that a single-slice CT scan (or other imaging technique) with or without DXA is required for accurate predictions of intraabdominal fat.

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Background-Electron-beam CT (EBCT) quantification of coronary artery calcification (CAC) allows noninvasive assessment of coronary atherosclerosis. We undertook a follow-up study to determine whether CAC extent, measured at the time of angiography by EBCT, predicted future hard cardiac events, comprising cardiac death and nonfatal myocardial infarction (MI). We also assessed the potential of selected coronary artery disease (CAD) risk factors, prior CAD event history (MI or revascularization), and angiographic findings (number of diseased vessels and overall disease burden) to predict subsequent hard events. Methods and Results-Two hundred eighty-eight patients who underwent contemporaneous coronary angiography and EBCT scanning were contacted after a mean of 6.9 years. Vital status and history of MI during follow-up were determined. Cox proportional hazards models were used to compare the predictive ability of CAC extent with selected CAD risk factors, CAD event history, and angiographic findings. Median CAC score was 160 (range 0 to 7633). The 22 patients who experienced hard events during follow-up were older and had more extensive CAC and angiographic disease (PϽ0.05). Only 1 of 87 patients with CAC score Ͻ20 experienced a subsequent hard event during follow-up. Event-free survival was significantly higher for patients with CAC scores Ͻ100 than for those with scores Ն100 (relative risk 3.20; 95% CI

Polycystic ovary syndrome (PCOS), a common endocrine disorder of reproductive-aged women, is associated with multiple risk factors for coronary heart disease (CHD), such as diabetes mellitus, dyslipidemia, visceral obesity, and hypertension. However, premature coronary atherosclerosis has not been demonstrated in PCOS women. Electron beam computed tomography (EBCT) noninvasively measures coronary artery calcium (CAC), a marker for coronary atherosclerosis. We measured CAC by EBCT in 30- to 45-yr-old premenopausal PCOS women and compared the results to CAC in 1) recruited normal ovulatory volunteers matched for age and weight to the PCOS cohort, and 2) community-dwelling women of similar age in an extant coronary calcium database. Healthy, community-dwelling, ovulatory controls (n = 71) were matched by age and body mass index (BMI) to PCOS women (n = 36). Women with diabetes or known CHD were excluded. Subjects underwent EBCT scanning, oral glucose tolerance testing, and CHD risk factor assessment. PCOS women had significantly higher levels of serum total and low density lipoprotein cholesterol and testosterone levels than matched controls. PCOS and control women were obese and had a greater mean BMI than community-dwelling women (33 kg/m(2) for PCOS vs. 31 kg/m(2) for control; P < 0.001). CAC was more prevalent in PCOS women (39%) than in matched controls (21%; odds ratio, 2.4; P = 0.05) or community-dwelling women (9.9%; odds ratio, 5.9; P < 0.001). BMI, waist circumference, and total and low density lipoprotein cholesterol levels predicted CAC prevalence after adjustment for BMI. CAC is more prevalent in PCOS women than in obese or nonobese women of similar age. PCOS women are at increased risk for atherosclerosis and should be targeted for primary prevention of CHD.

Background-Electron-beam computed tomography (EBCT) is used to measure coronary calcification but not for aortic valve calcification (AVC). Its accuracy, association with aortic stenosis (AS) severity, and diagnostic and prognostic value with respect to AVC are unknown. Methods and Results-In 30 explanted aortic valves, the AVC score by EBCT (1125Ϯ1294 Agatston units [AU]) showed a strong linear correlation (rϭ0.96, PϽ0.0001) with valvular calcium weight (653Ϯ748 mg) by pathology that allowed estimation of calcium weight as AVC score/1.7, with a small standard error of the estimate (53 mg). In 100 consecutive clinical patients, we measured AVC by EBCT and AS severity by echocardiographic aortic valve area (AVA). The AVC score was 1316Ϯ1749 AU (range 0 to 7226 AU). Intraobserver and interobserver variabilities were excellent (4Ϯ4% and 4Ϯ10%, respectively). AVC and AVA were strongly associated (rϭ0.79, PϽ0.0001) but had a curvilinear relationship that suggested that AVC and AVA provide complementary information. AVC score Ն1100 AU provided 93% sensitivity and 82% specificity for diagnosis of severe AS (AVA Ͻ1 cm 2 ), with a receiver operator characteristic curve area of 0.89. AVC assessment by echocardiography was often more severe than by EBCT (PϽ0.0001). During follow-up, 22 patients either died, developed heart failure, or required surgery. With adjustment for age, sex, symptoms, ejection fraction, and AVA, the AVC score was independently predictive of event-free survival (risk ratio 1.06 per 100-AU increment [1.02 to 1.10], PϽ0.001), even after adjustment for echocardiographic calcifications. Conclusions-AVC is accurately and reproducibly measured by EBCT and shows a strong association and diagnostic value for severe AS. The curvilinear relationship between AVC and AVA suggests these measures are complementary, and indeed, AVC provides independent outcome information. Thus, AVC is an important measurement in the evaluation of patients with AS.

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