First Case of Regression of Carcinoid Heart Disease on Serial Transthoracic Echocardiograms following Octreotide Monotherapy in a Patient with Metastatic Pancreatic Neuroendocrine Tumor

Well-differentiated neuroendocrine tumors (NETs) arising in the gastrointestinal (GI) tract and pancreas are relatively rare; however, the annual incidence has been increasing. Carcinoid syndrome (CS) is a constellation of symptoms that occur when a GI NET metastasizes to the liver and releases high levels of vasoactive substances into the systemic circulation. CS occurs in 19% of NETs patients at diagnosis and is associated with shorter survival. Carcinoid heart disease (CHD) occurs in over 50% of patients with CS and is associated with poor long-term prognosis. NET-induced valvular fibrosis is a significant cause of mortality and morbidity in these patients. Somatostatin analogs relieve CS symptoms, but they have never been shown to reverse CHD progression or improve overall survival. Surgical therapy for right-sided valve disease is associated with improved symptoms and quality of life and possibly improved survival, despite relatively high morbidity and mortality associated with cardiac intervention. A 65-year-old woman with a metastatic pancreatic NET had typical signs and symptoms of CS. She presented in congestive heart failure and was found to have severe tricuspid regurgitation with characteristic features of CHD on transthoracic echocardiogram (TTE). Following octreotide monotherapy, serial TTEs demonstrated regression of tricuspid valve involvement. The patient improved clinically and remained asymptomatic on subsequent visits. This is the first case of CHD regression with medical therapy supported by serial TTEs. Developing a deeper understanding of cases like this will help us unlock new intervention targets and strategies for treatments in the future.