Iron Deficiency in Heart Failure: A Scientific Statement from the Heart Failure Society of America

Iron deficiency is present in approximately 50% of patients with symptomatic heart failure and is independently associated with worse functional capacity, lower quality of, life and increased mortality. The purpose of this document is to summarize current knowledge of how iron deficiency is defined in heart failure and its epidemiology and pathophysiology, as well as pharmacological considerations for repletion strategies. This document also summarizes the rapidly expanding array of clinical trial evidence informing when, how, and in whom to consider iron repletion.     

A Hyperkinetic Heart in Uncomplicated Active Acromegaly

Cardiac function was studied by echocardiography in 12 patients with active acromegaly and in 12 age- and sex-matched healthy control subjects. None of the patients had cardiovascular diseases or other endocrine diseases than acromegaly. The patients had a mean age of 39±5 years and were short-term acromegalic with a mean duration of disease of 6±3 years. Mean left ventricular mass was 163±43 g/m² in the acromegalic group versus 120±24 g/m² in the control group. Preload (the diastolic diameter of the left ventricle) was within normal limits, while afterload (end-systolic meridional wall stress) was significantly decreased in the acromegalic group. Myocardial contractility assessed as fractional shortening of the left ventricle was 39.9±3.6% in the acromegalic group versus 32.9±5.1% in the control group, and cardiac output was increased by 52% in the acromegalic group because of increased heart rate and stroke volume. We suggest that augmented peripheral blood flow is responsible for the condition of cardiac hyperkinesia in short-term acromegaly and involved in the development of hypertension, which is a frequent complication of long-term acromegaly.     

A Novel Role for Serotonin in Heart

Congenital heart disease is a major cause of disability and morbidity, often initiated by both environmental components and genetic susceptibility. Identification of factors controlling myocardial differentiation and proliferation is of great importance for understanding the pathogenesis of congenital heart diseases. Several lines of evidence suggest that serotonin [5-hydroxytryptamine (5-HT)] regulates cardiovascular functions during embryogenesis and adulthood. However, the molecular mechanism by which 5-HT regulates embryonic development of heart and cardiovascular functions remained unknown until recently. Inactivation of the 5-HT_2B receptor (5-HT_2BR) gene leads to embryonic and neonatal death due to the following defects in the heart: (a) 5-HT_2BR mutant embryos exhibit a lack of trabeculae in the heart and a reduction in the expression levels of a tyrosine kinase receptor, called ErbB-2, leading to mid-gestation lethality. These in vivo data suggest that the Gq-coupled 5-HT_2BR uses the signaling pathway of the tyrosine kinase receptor ErbB-2 for cardiac differentiation. (b) Newborn 5-HT_2BR mutant mice exhibit cardiac dilation resulting from contractility deficits and structural deficits at the intercellular junctions between cardiomyocytes. (c) In adult 5-HT_2BR mutant mice, echocardiography and electrocardiography confirm the presence of left ventricular dilation and decreased systolic function. These results constitute the first genetic evidence that 5-HT via the 5-HT_2BR, regulates differentiation and proliferation during development as well as cardiac structure and function in adults.     

Innovations in Heart Transplantation: A Review

Advanced heart failure affects tens of thousands of people in the United States alone with high morbidity and mortality. Cardiac transplantation offers the best treatment strategy, but has been limited historically by donor availability. Recently, there have been significant advances in organ allocation, donor–recipient matching, organ preservation, and expansion of the donor pool. The current heart allocation system prioritizes the sickest patients to minimize waitlist mortality. Advances in donor organ selection, including predicted heart mass calculations and more sophisticated antibody detection methods for allosensitized patients, offer more effective matching of donors and recipients. Innovations in organ preservation such as with organ preservation systems have widened the donor pool geographically. The use of donors with hepatitis C is possible with the advent of effective direct-acting antiviral agents to cure donor-transmitted hepatitis C. Finally, further expansion of the donor pool is occurring with the use of higher risk donors with advanced age, medical comorbidities, and left ventricular dysfunction and advances in donation after circulatory death. This review provides an update on the new technologies and transplantation strategies that serve to widen the donor pool and more effectively match donors and recipients so that heart transplant candidates may derive the best outcomes from heart transplantation.