South Asian (Indian, Pakistani, Bangladeshi, Nepali, and Sri Lankan) individuals have high rates of cardiovascular disease that is not explained by traditional cardiovascular risk factors. Though South Asians represent over one-quarter of the world's population, there are no longitudinal studies in this high-risk ethnic group. The investigators aim to establish a longitudinal study of South Asians at three United States centers to identify risk factors linked to subclinical atherosclerosis and incident cardiovascular disease. The purpose of this study is to understand the causes of heart disease and stroke in South Asians and compare these causes to those in other United States ethnic groups.