Recent trends including development of new diagnostic and therapeutic modalities and increasing pressure to provide cost-effective care have made risk stratification and technology assessment increasingly important in cardiovascular research. This will be achieved through a series of studies exploring the utility of echocardiography in the risk stratification of patients with chest pain. We hypothesize that routinely available qualitative data from the echocardiogram can be used to risk stratify patients and that such data provide information above and beyond clinical data. Thus, by means of a prospective cohort study, we will: 1) Investigate the correlation between echocardiographic variables and the risk of a. complications during hospitalization; and b. long-term prognosis and functional status. 2) Determine whether echocardiographic variables add incremental risk stratification information after consideration of clinical and electrocardiographic data. 3) Develop and validate prospectively a predictive algorithm based on clinical, electrocardiographic and echocardiographic variables. 4) Assess the cost-effectiveness of performance of routine echocardiography in subsets of patients admitted for acute chest pain. In the latter part of the research program, these methodologies for technologies for technology assessment will be used to evaluate the role of cardiac imaging in other settings such as identification of preoperative predictors of outcome in patients undergoing mitral valve repair and replacement or assessment of aortic regurgitation with magnetic resonance imaging. This research should prove useful to both clinician and health policy maker.