Managing carcinoid heart disease in patients with neuroendocrine tumors

Carcinoid heart disease is a complex clinical entity frequently complicating the course of neuroendocrine tumors and carcinoid syndrome and is associated with significant morbidity and mortality. Although the pathogenesis of carcinoid heart disease remains poorly understood, it appears that the exposure to excessive circulating levels of serotonin contribute a key role, triggering a cascade of events that ultimately results in the development of plaque-like material on the endocardial surfaces of the valve leaflets. The occurrence of carcinoid heart disease may initially run an asymptomatic period, followed by the development of symptoms of congestive cardiac failure. The diagnosis of carcinoid heart disease is suspected by raised biomarkers, such as serum NT-pro-BNP and confirmed by imaging modalities, with echocardiogram being the gold standard to date. Carcinoid heart disease treatment remains challenging as in addition to cardiac dysfunction, tumor burden needs to be tackled with, hence requiring a multidisciplinary approach. Therapy comprises watchful waiting during the first initial stages of the disease; medications for heart failure; optimal control of serotonin secretion from the NET with pharmacotherapy, interventional means or even surgical techniques; and, in selected patients, cardiac valve replacement. The current review summarizes the literature on the diagnosis and management of carcinoid heart disease.