What do we know about carcinoid heart disease in the present era?

Carcinoid heart disease (CHD) is a severe complication of carcinoid syndrome (CS) found primarily in patients with small intestine neuroendocrine neoplasms (SI-NENs). Patients who develop CHD have significantly worse morbidity and mortality outcomes, highlighting the importance of clinical practice recommendations for CHD screening, diagnosis, and treatment that are both consistent and practical. CHD is characterized by white plaque-like deposits on the endocardial surface of heart structures, generally affecting the right heart valves, causing tricuspid and pulmonary regurgitation and, less commonly, valve stenosis. Cardiac imaging is essential for both the diagnosis and management of CHD. Previously, imaging for CHD was mostly achieved by echocardiography, but more recently, imaging has become multimodal. N-terminal pro-B-type natriuretic peptide (NT-proBNP) and 5-hydroxyindoleacetic acid in the urine (u5-HIAA) are currently the most effective markers used in screening CS patients and evaluating CHD severity. Managing patients with CHD is challenging since both systemic malignant disease and cardiac involvement must be treated concurrently. Early diagnosis and surgical intervention when required are critical to patient prognosis, especially in those without primary tumor resection. Valve replacement surgery is the most effective treatment for patients with advanced carcinoid heart disease for alleviating cardiac symptoms and contributing to survival outcomes. To deliver effective patient treatment, multidisciplinary team collaboration is needed. This review summarizes current research findings on CHD pathogenesis, clinical and epidemiological features, useful biomarkers and imaging modalities, and treatment strategies.