 This study will examine previously collected data from participants in the Cardiovascular Health Study. There will be no study visits specifically for this study. Plasma samples obtained from participants will be analyzed for the presence of n-3 fatty acids and trans-fatty acids. The study will also determine the incidence of CHF, AF, and stroke and the way in which fatty acids are related to hemodynamics, heart structure and function, electrophysiology, insulin sensitivity, inflammation, endothelial function, and obesity. 