Endocrine Challenges in Patients with Continuous-Flow Left Ventricular Assist Devices

Abstract

Heart failure (HF) remains a leading cause of morbidity, hospitalization, and mortality worldwide. Advancement of mechanical circulatory support technology has led to the use of continuous-flow left ventricular assist devices (LVADs), reducing hospitalizations, and improving quality of life and outcomes in advanced HF. Recent studies have highlighted how metabolic and endocrine dysfunction may be a consequence of, or associated with, HF, and may represent a novel (still neglected) therapeutic target in the treatment of HF. On the other hand, it is not clear whether LVAD support, may impact the outcome by also improving organ perfusion as well as improving the neuro-hormonal state of the patients, reducing the endocrine dysfunction. Moreover, endocrine function is likely a major determinant of human homeostasis, and is a key issue in the recovery from critical illness. Care of the endocrine function may contribute to improving cardiac contractility, immune function, as well as infection control, and rehabilitation during and after a LVAD placement. In this review, data on endocrine challenges in patients carrying an LVAD are gathered to highlight pathophysiological states relevant to this setting of patients, and to summarize the current therapeutic suggestions in the treatment of thyroid dysfunction, and vitamin D, erythropoietin and testosterone administration.

Cellular and Molecular Mechanisms Activated by a Left Ventricular Assist Device

“…Vitamin D deficiency is frequently encountered in patients with congestive HF and has been associated with a higher risk for postoperative driveline infections, stroke, and mortality in CHF patients undergoing LVAD surgery [ 154 , 155 , 156 , 157 ]. Optimal levels for vitamin D supplementation range from 400 to 2000 IU daily, with 4000 IU per day being the upper daily limit indicated by several health organizations including the Institute of Medicine (USA) and the European Food and Safety Authority [ 158 ]. However, the preoperative supplementation for LVAD patients was reported to not be effective because small to no significant differences were obtained upon either daily, weekly, or high-dose monthly supplementation of vitamin D, as reported in the panel of studies listed in Busa et al, 2020 [ 156 ].…”

“…Other deficiencies associated with heart diseases (e.g., acute coronary artery disease) is selenium, an essential nutrient used for the enzymatic activity of selenoproteins [ 160 ]. In LVAD patients, who are frequently immunosuppressed and exhibit thyroid dysfunction [ 158 ], these proteins are likely to play a key role by enhancing antioxidant defense, thyroid functioning, and immunity responses [ 160 ]. Differently from other deficiencies, selenium supplementation in LVAD patients has been reported to be effective in compensating for low selenium levels and promoting slightly better physical functioning, but no detectable improved quality of life [ 148 ].…”