Advanced Carcinoid Tricuspid Valve Disease Associated with Delayed Recognition and Loss of the Interventional Window in a Patient with Ileal Neuroendocrine Tumor: A Case Report

Background and Clinical Significance: Carcinoid heart disease remains one of the most serious complications of carcinoid syndrome, yet cardiac involvement may still be recognized late, when valvular damage is already advanced and treatment options are limited. Case Presentation: We report a 70-year-old man with a well-differentiated ileal neuroendocrine tumor (NET G2, Ki-67 up to 5%), diagnosed in December 2019. Over six years, the disease progressed with liver metastases, markedly rising 24 h urinary 5-HIAA levels and clinically active carcinoid syndrome, and was treated sequentially with somatostatin analogues, everolimus and 177Lu-DOTATOC. Throughout this period, oncological evaluation was frequent, whereas structured cardiac assessment was essentially absent until 2025. When the patient was referred for evaluation for transcatheter tricuspid repair, echocardiography demonstrated advanced carcinoid tricuspid valve disease with severe regurgitation, mild stenosis, marked leaflet thickening and tethering, and a coaptation gap of 17 mm—far beyond the ~7 mm threshold associated with favorable edge-to-edge repair and the >10 mm range associated with poor outcome. Because of the advanced valve remodeling and the overall clinical burden, the patient was not a candidate for transcatheter edge-to-edge repair or surgery and subsequently died. Conclusions: This case illustrates how carcinoid heart disease can progress beyond correctability and supports regular echocardiographic surveillance in patients with carcinoid syndrome, so that valve involvement is identified while intervention is still anatomically feasible.