Coronary calcium score improves classification of coronary heart disease risk in the elderly: the Rotterdam study.

OBJECTIVES: The purpose of this study was to examine the effect of coronary artery calcium (CAC) on the classification of 10-year hard coronary heart disease (CHD) risk and to empirically derive cut-off values of the calcium score for a general population of elderly patients. BACKGROUND: Although CAC scoring has been found to improve CHD risk prediction, there are limited data on its impact in clinical practice. METHODS: The study comprised 2,028 asymptomatic participants (age 69.6 ± 6.2 years) from the Rotterdam Study. During a median follow-up of 9.2 years, 135 hard coronary events occurred. Persons were classified into low (<10%), intermediate (10% to 20%), and high (>20%) 10-year coronary risk categories based on a Framingham refitted risk model. In a second step, the model was extended by CAC, and reclassification percentages were calculated. Cutoff values of CAC for persons in the intermediate-risk category were empirically derived based on 10-year hard CHD risk. RESULTS: Reclassification by means of CAC scoring was most substantial in persons initially classified as intermediate risk. In this group, 52% of men and women were reclassified, all into more accurate risk categories. CAC values above 615 or below 50 Agatston units were found appropriate to reclassify persons into high or low risk, respectively. CONCLUSIONS: In a general population of elderly patients at intermediate CHD risk, CAC scoring is a powerful method to reclassify persons into more appropriate risk categories. Empirically derived CAC cutoff values at which persons at intermediate risk reclassified to either high or low risk were 615 and 50 Agatston units, respectively.

Intake of fish and marine n-3 fatty acids in relation to coronary calcification: the Rotterdam Study.

BACKGROUND: Epidemiologic and experimental data suggest a cardioprotective effect of n-3 (omega-3) fatty acids from fish [eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA)]. OBJECTIVE: The objective was to examine the association of fish and EPA plus DHA intakes with coronary calcification in a general older population. DESIGN: Diet was assessed between 1990 and 1993 by using a semiquantitative 170-item food-frequency questionnaire. Coronary calcification was assessed approximately 7 y later by electron-beam computed tomography in 1570 asymptomatic cardiac subjects with complete dietary data (44% men, mean age of 64 y). Calcium scores according to Agatston's method were divided into < or = 10 (no/minimal coronary calcification), 11-400 (mild/moderate calcification), and > 400 (severe calcification). Prevalence ratios (PRs) for mild/moderate and severe calcification were obtained in categories of fish and EPA plus DHA intake. PRs were adjusted for age, sex, body mass index, diabetes mellitus, socioeconomic status, smoking, alcohol intake, physical activity, and dietary factors. RESULTS: Subjects with a fish intake > 19 g/d had a significantly lower prevalence of mild/moderate calcification (PR: 0.87; 95% CI: 0.78, 0.98; full model) than did subjects who consumed no fish. Subjects with a high fish intake also had a lower prevalence of severe calcification (PR: 0.88; 95% CI: 0.74, 1.04), which was borderline statistically significant. EPA plus DHA intake showed no significant associations (PR: 0.93 and 0.97, respectively; P > 0.05). CONCLUSIONS: We found a weak inverse association between fish intake and coronary calcification. If confirmed in other population-based studies, more research is warranted to determine which components in fish can inhibit vascular calcification.

Volumetric measurement of pulmonary nodules at low-dose chest CT: effect of reconstruction setting on measurement variability.

OBJECTIVE: To assess volumetric measurement variability in pulmonary nodules detected at low-dose chest CT with three reconstruction settings. METHODS: The volume of 200 solid pulmonary nodules was measured three times using commercially available semi-automated software of low-dose chest CT data-sets reconstructed with 1 mm section thickness and a soft kernel (A), 2 mm and a soft kernel (B), and 2 mm and a sharp kernel (C), respectively. Repeatability coefficients of the three measurements within each setting were calculated by the Bland and Altman method. A three-level model was applied to test the impact of reconstruction setting on the measured volume. RESULTS: The repeatability coefficients were 8.9, 22.5 and 37.5% for settings A, B and C. Three-level analysis showed that settings A and C yielded a 1.29 times higher estimate of nodule volume compared with setting B (P = 0.03). The significant interaction among setting, nodule location and morphology demonstrated that the effect of the reconstruction setting was different for different types of nodules. Low-dose CT reconstructed with 1 mm section thickness and a soft kernel provided the most repeatable volume measurement. CONCLUSION: A wide, nodule-type-dependent range of agreement between volume measurements with different reconstruction settings suggests strict consistency is required for serial CT studies.