DOI: 10.1111/j.1540-8175.2009.01072.x C  2010, Wiley Periodicals, Inc. Aortic Root Dimension as an Independent Predictor for All-Cause Death in Adults <65 Years of Age (from The Chin-Shan Community Cardiovascular Cohort Study) Chao-Lun Lai, M.D., ∗ Kuo-Liong Chien, M.D., Ph.D.,†‡ Hsiu-Ching Hsu, Ph.D.,‡ Ta-Chen Su, M.D., Ph.D.,‡ Ming-Fong Chen, M.D., Ph.D.,‡ and Yuan-Teh Lee, M.D., Ph.D.§ ∗ Cardiovascular Center, Far Eastern Memorial Hospital, Taiwan; †Institute of Preventive Medicine, College of Public Health, National Taiwan University, Taiwan; ‡Department of Internal Medicine, National Taiwan University Hospital, Taiwan; and §China Medical University, Taiwan Background: Evidence on aortic root dimension for predicting cardiovascular morbidity and mortality is inconclusive. This cohort study sought to characterize the predictive power of aortic root dimension on cardiovascular morbidity and mortality in an ethnic Chinese population. Methods: We recruited 1,851 participants in the Chin–Shan Community Cardiovascular Cohort (CCCC) study who had received echocardiography without previous cardiovascular events. Aortic root dimension was measured by M- mode echocardiography and indexed by body surface area to obtain aortic root dimension index (AOI). The end points were all-cause death and incident cardiovascular events including coronary heart disease and stroke over a median follow-up of 11.9 years. Results: Although tertiles of AOI was associated with an increased risk of cardiovascular events and all-cause death in univariate analysis, the significance diminished after adjusting for age variable (P for trend = 0.11 for cardiovascular events; P for trend = 0.23 for all-cause death). In subgroup analysis, we found a significant association between tertiles of AOI and risk of all-cause death in the final multivariate Cox regression model in adults <65 years. The adjusted relative risk was 1.88 (95% CI, 1.04 to 3.40) in participants in the upper tertile of AOI compared with participants in the lower tertile (P for trend = 0.037). In adults ≥65 years, tertile of AOI was not associated with all-cause death (P for trend = 0.14). Tertiles of AOI was not associated with cardiovascular events throughout this study. Conclusion: Our study showed a significant association between AOI and all-cause death in adults <65 years in an ethnic Chinese population. (Echocardiography 2010;27:487- 495) Key words: aorta, echocardiography, mortality, prognosis, risk factors Echocardiography possesses the advantage of noninvasiveness and comprehensive acquisi- tion of relevant parameters about cardiac func- tion. Therefore, many population studies investi- gated the predictive value of echocardiographic measures for cardiovascular morbidity and mortality. 1–8 Sources of Funding: the National Science Council (NSC 97-2314-B-002-130-MY3 & NSC 97-3112-B-002-034) in Taiwan. Potential conflicts of interest: None. Address for correspondence and reprint requests: Kuo-Liong Chien, M.D., Ph.D. and Yuan-Teh Lee, M.D., Ph.D., Room 517, No. 17, Hsu-Chou Road, Taipei, Taiwan, 100, Institute of Preventive Medicine, College of Public Health, National Taiwan University. Fax: +886-2-2392-0456; E-mail: klchien@ntu.edu.tw; ytlee@ntu.edu.tw Larger aortic root dimension was associated with higher left ventricular mass and lower left ventricular systolic function. 9,10 And both higher left ventricular mass and lower left ventricular systolic function were associated with worse car- diovascular outcomes. 2,6 This led to the hypoth- esis that larger aortic root dimension was inde- pendently associated with worse cardiovascular outcomes. One report asserted that aortic root dimension was predictive of cardiovascular mor- bidity and mortality in a population consisted of black and white men and women >65 years. 11 However, similar investigations on aortic root di- mension for predicting cardiovascular morbidity and mortality in younger age population were scarce in the literature. We investigated the association between aor- tic root dimension and cardiovascular events and all-cause death in an ethnic Chinese population. 487