Carcinoid heart disease (CHD) is a rare cardiac complication that occurs most commonly in patients with advanced neuroendocrine tumors and is a known sequela of carcinoid syndrome. Neuroendocrine tumors most widely associated with CHD include tumors in the small bowel, followed by lung, large bowel, pancreatic, appendiceal, and ovarian neoplasms. Carcinoid syndrome is a paraneoplastic syndrome caused by the release of serotonin and other substances from neuroendocrine tumors. It results in a spectrum of symptoms, including diarrhea, flushing, bronchospasm, and symptoms of congestive heart failure. Without treatment and for patients with advanced heart failure, the prognosis of CHD can be less than a year. Management of CHD is often challenging as patients typically present late, and the disease can progress rapidly. Therefore, optimal management of these patients requires close collaboration among various specialties to quantify disease burden, delay the progression of valvular disease, and determine the most effective surgical and medical management strategies depending on the cardiac manifestations to improve quality of life and reduce mortality. This involves a collaborative team, including cardiology and oncology, and often involves many other disciplines, including hepatobiliary and cardiovascular surgeons, endocrinologists, anesthesiologists, and gastroenterologists.

Carcinoid heart disease (CHD) is a rare but potentially life-threatening sequela of advanced neuroendocrine neoplasm with carcinoid syndrome. These tumors can secrete vasoactive substances of which serotonin is the most prevalent. Carcinoid heart disease typically involves the right-sided heart valves and eventually leads to right heart failure. Monitoring N-terminal pro–B-type natriuretic peptide and 5-hydroxyindoleacetic acid at diagnosis and during treatment, as well as cardiac echocardiogram, helps to screen for CHD. Many patients are not screened for this appropriately. Multidisciplinary care for patients with CHD is ideal and involves medical oncology, cardiology, and cardiothoracic surgery.

Carcinoid Heart DiseaseA 67-year-old man presented with a 1-month history of dyspnea and diarrhea. Thickened, stiff tricuspid-valve leaflets and tricuspid regurgitation were seen on transthoracic echocardiography (shown in videos), and abdominal imaging showed liver masses.

Carcinoid syndrome is the term applied to a constellation of symptoms mediated by a variety of humoral factors produced by the well-differentiated neuroendocrine tumours (NET) localised usually in the gastrointestinal tract and the lungs. This syndrome includes a characteristic triad of diarrhea, flushing and cardiac disease. This cardiopathy occurs in 20 % of the cases and prevails on the right side of the heart. It evolves to a potentially severe heart failure. Therefore, early diagnosis and appropriate cardiac care are crucial to improve the prognosis of these patients. We report a case of a carcinoid syndrome with a trivalvular insufficiency and cardiac decompensation which required surgical replacement of the tricuspid and aortic valves.

Carcinoid heart disease is seen in 50% of patients with carcinoid syndrome and is the main cause of morbidity and mortality. The pathophysiology of carcinoid heart disease is still poorly understood; however, the disease is believed to be caused by chronic exposure to excessive circulating vasoactive substances produced by the neuroendocrine tumors. The advancement of cardiac imaging modalities, antitumor treatment, and cardiac surgery, has improved the prognosis of patients with carcinoid heart disease. Cardiac surgery is the most effective treatment in these patients and is recommended to be performed in an experienced center by a multidisciplinary team. Abbreviations: 5-HT: 5-hydroxytryptamine; CHD: carcinoid heart disease; TGF-β:transforming growth factor beta; ECM: extracellular matrix; 5-HIAA: 5-hydroxyindoleacetic acid; CgA: chromogranin A; NT-proBNP: B-type natriuretic peptide

Rare neuroendocrine tumours (NETs) that most commonly arise in the gastrointestinal tract can lead to carcinoid syndrome and carcinoid heart disease. Patients with carcinoid syndrome present with vasomotor changes, hypermotility of the gastrointestinal system, hypotension and bronchospasm. Medical therapy for carcinoid syndrome, typically with somatostatin analogues, can help control symptoms, inhibit tumour progression and prolong survival. Carcinoid heart disease occurs in more than 50% of these patients and is the initial presentation of carcinoid syndrome in up to 20% of patients. Carcinoid heart disease has characteristic findings of plaque-like deposits composed of smooth muscle cells, myofibroblasts, extracellular matrix and an overlying endothelial layer which can lead to valve dysfunction. Valvular dysfunction can lead to oedema, ascites and right-sided heart failure. Medical therapy of carcinoid heart disease is limited to symptom control and palliation. Valve surgery for carcinoid heart disease should be considered for symptomatic patients with controlled metastatic carcinoid syndrome. A multidisciplinary approach is needed to guide optimal management.