The burden of neurologic diseases, including stroke and dementia, is expected to grow substantially in the coming decades. Thus, achieving optimal brain health has been identified as a public health priority and a major challenge. Cardiovascular diseases are the leading cause of death and disability in the United States and around the world. Emerging evidence shows that the heart and the brain, once considered unrelated organ systems, are interdependent and linked through shared risk factors. More recently, studies designed to unravel the intricate pathogenic mechanisms underpinning this association show that people with various cardiac conditions may have covert brain microstructural changes and cognitive impairment. These findings have given rise to the idea that by addressing cardiovascular health earlier in life, it may be possible to reduce the risk of stroke and deter the onset or progression of cognitive impairment later in life. Previous scientific statements have addressed the association between cardiac diseases and stroke. This scientific statement discusses the pathogenic mechanisms that link 3 prevalent cardiac diseases of adults (heart failure, atrial fibrillation, and coronary heart disease) to cognitive impairment.