 Cardiovascular disease is a major cause of morbidity and mortality. There is recent evidence that infection due to influenza may precipitate vascular events such as myocardial infarctions and strokes. There is some evidence that influenza vaccination may prevent such events but the data are inconclusive. The investigators propose a randomized controlled trial to assess whether influenza vaccination will prevent vascular illness. Adults with clinical heart failure will be randomized to inactivated influenza vaccine or saline placebo. This pilot study will provide needed data to establish the feasibility of a larger study. 