Abstract This expert consensus statement summarizes the available data regarding the prognostic value of CAC in the asymptomatic population and its ability to refine individual risk prediction, ...addresses the limitations identified in the current traditional risk factor-based treatment strategies recommended by the 2013 ACC/AHA Prevention guidelines including use of the Pooled Cohort Equations (PCE), and the US Preventive Services Task Force (USPSTF) Recommendation Statement for Statin Use for the Primary Prevention of Cardiovascular Disease in Adults. It provides CAC based treatment recommendations both within the context of the shared decision making model espoused by the 2013 ACC/AHA Prevention guidelines and independent of these guidelines.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Abstract Coronary artery calcium (CAC) scanning is an important tool for risk stratification in intermediate-risk, asymptomatic subjects without previous coronary disease. However, the clinical ...benefit of improved risk prediction needs to be balanced against the risk of the use of ionizing radiation. Although there is increasing emphasis on the need to obtain CAC scans at low-radiation exposure to the patient, very few practical documents exist to aid laboratories and health care professionals on how to obtain such low-radiation scans. The Tomographic Imaging Council of the Society for Atherosclerosis Imaging and Prevention, in collaboration with the Prevention Council and the Society of Cardiovascular Computed Tomography, created a task force and writing group to generate a practical document to address parameters that can be influenced by careful attention to image acquisition. Patient selection for CAC scanning should be based on national guidelines. It is recommended that laboratories performing CAC examinations monitor radiation exposure (dose-length-product DLP) and effective radiation dose (E) in all patients. DLP should be <200 mGy × cm; E should average 1.0–1.5 mSv and should be <3.0 mSv. On most scanner platforms, CAC imaging should be performed in an axial mode with prospective electrocardiographic triggering, using tube voltage of 120 kVp. Tube current should be carefully selected on the basis of patient size, potentially using chest lateral width measured on the topogram. Scan length should be limited for the coverage of the heart only. When patients and imaging parameters are selected appropriately, CAC scanning can be performed with low levels of radiation exposure.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Abstract Background Left ventricular (LV) volume and mass have prognostic relevance. Overall size of the left ventricle as it appears in noncontrast CT is a composite of the ventricular volume and ...myocardial mass. We describe a method to estimate the LV size using a single cross-section in noncontrast CT and determined normal ranges on the basis of a large population cohort. Methods The Multi-Ethnic Study of Atherosclerosis with 6814 participants from 4 ethnicities who were free of known cardiovascular disease and enrolled between 2000 and 2002 form the basis of our analysis. LV size was calculated from a single cross-sectional slice obtained by either nonenhanced electron beam or multidetector CT. LV size was adjusted to body surface area to obtain the LV size index, which was adjusted for age, sex, race or ethnicity, hypertension, hyperlipidemia, and diabetes. Results There were significant differences in LV size index by race which were further influenced by age and sex. Higher values were noted in men in all ethnic groups across all age groups. Similarly, LV size index uniformly decreased with age across all ethnic and sex categories. Caucasians had the lowest and African Americans had the highest LV size index across all age and sex categories. In multivariate regression analyses adjusted for age, sex, race or ethnicity, hypertension, hyperlipidemia, smoking, and diabetes mellitus, the significant differences were noted between male vs female (median difference, 17.5 cc/m2 ; P < .001), ethnic groups (Caucasian, reference group; Asian, 3.7 cc/m2 ; African American, 8.3 cc/m2 ; and Hispanic, 5.6 cc/m2 ; P < .001), and age groups (45–54 years, reference group; 55–64 years, −5.2 cc/m2 ; 65–74 years, −11.4 cc/m2 ; and 74–84 years, −12.5 cc/m2 ). Conclusions This study provides normative values for LV size as determined from a single, nonenhanced CT cross-section and indexed to body surface area, and it demonstrates that the LV size index varies by age, sex, and ethnic background.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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