Heart failure (HF) is the fastest growing cardiovascular condition in the United States, and along with the growth of the elderly population, the number of adults affected by HF will increase both nation- and worldwide. To those individuals affected by HF, this condition confers enormous symptom burden, severe functional limitations, and reduced quality of life. Despite the importance of symptom burden in HF, however, there is a limited understanding of the biological underpinnings of symptoms in HF, including how accelerated biological aging intersects with symptoms. The purpose of this program of research was to elucidate the biological underpinnings of symptoms among adults with HF, particularly the role of accelerated biological aging in explaining symptoms in HF.