Monocyte Phenotypic Changes in Heart Failure

There are many treatments that can improve how long and how well people live with heart failure when they are outside the hospital. However, the investigators know less about how to effectively treat hospitalized heart failure patients so that they do not have to return to the hospital after they go home. Part of the problem is that the investigators don't understand all of the causes of worsening heart failure. Previous studies by other researchers suggest that white blood cells called monocytes are over-active in heart failure. Under normal conditions monocytes help fight infections in the body, but over-active monocytes release chemicals that could cause abnormal function of the heart and blood vessels. The investigators' research group believes that over-active monocytes may be an important reason that heart failure worsens before hospitalization. In this study the investigators will collect blood samples on the day a patient comes into the hospital, the day they return home, and the day they come back to the clinic for a follow-up appointment. The investigators will measure the inflammation in the bloodstream and the activity of monocytes from the patients' blood to see if there are changes in these measurements as heart failure improves. The investigators will also call each patient several times after they return home to ask questions about how they are doing.