Abstract-Heart failure affects ≈23 million people worldwide and continues to have a high mortality despite advancements in modern pharmacotherapy and device therapy. HF is a complex clinical syndrome that can result in the impairment of endocrine, hematologic, musculoskeletal, renal, respiratory, peripheral vascular, hepatic, and gastrointestinal systems. Although gastrointestinal involvement and hepatic involvement are common in HF and are associated with increased morbidity and mortality, their bidirectional association with HF progression remains poorly fathomed. The current understanding of multiple mechanisms, including proinflammatory cytokine milieu, hormonal imbalance, and anabolic/ catabolic imbalance, has been used to explain the relationship between the gut and HF and has been the basis for many novel therapeutic strategies. However, the failure of these novel therapies such as anti-tumor necrosis factor-α has resulted in further complexity. Key Words: gastrointestinal tract ◼ heart failure H eart failure (HF) is a systemic disorder caused by the inability of the heart to accommodate the venous return and to maintain sufficient cardiac output to meet the body's metabolic needs.1 These hemodynamic perturbations result in a state of systemic inflammation with well-described and well-studied consequences in a variety of other organ systems, including the renal, cerebral, musculoskeletal, and immune systems. In contrast, the gastrointestinal and hepatic systems have received less attention, although gastrointestinal symptoms are common. With increasing clinical efforts to resuscitate the advanced HF patient, a greater appreciation and a better understanding of the gastrointestinal and hepatic manifestations of HF are needed.
2,3With some notable exceptions, gastrointestinal and hepatic involvement in heart disease has historically received little attention from cardiologists. 4 Mechanisms of gastrointestinal and hepatic dysfunction remain poorly understood despite the common presence of gastrointestinal-related symptoms and the increased morbidity and mortality associated with their presence. The specific involvement of the gastrointestinal system in HF results in a bidirectional relationship that has been called the cardiointestinal syndrome.5 For example, the systemic volume overload characteristic of HF is generally accompanied by concomitant gut edema, which can lead to bacterial translocation into the systemic circulation. Consequent monocyte activation and excessive cytokine release result in systemic inflammation, increased symptoms, and disease progression. In this review, we describe the current state of understanding of the gastrointestinal and hepatic systems in HF. Although nutritional status is also relevant in this discussion, we refer the reader to other excellent reviews of nutritional aspects of chronic disease.
7,8The Gut in HF
Gastrointestinal System as a Venous ReservoirStudies of implantable hemodynamic monitors to manage HF patients document that acute decompensated HF was not associ...