From Carcinoid Syndrome to Carcinoid Heart Disease: The Cost of Delayed Cardiac Surveillance.

Carcinoid heart disease (CHD) is a serious cardiac manifestation of carcinoid syndrome (CS), characterized by progressive fibrotic degeneration of cardiac valves and right-sided heart failure. We report the case of a 72-year-old man with a history of metastatic small-intestinal neuroendocrine tumor and CS diagnosed four years earlier, who presented with worsening dyspnea and peripheral edema. Transthoracic echocardiography revealed characteristic findings of advanced CHD, including severely thickened, retracted, and immobile tricuspid and pulmonary valve leaflets, resulting in severe tricuspid and pulmonary regurgitation. Additional findings included right ventricular dilatation, severe biatrial enlargement, moderate mitral regurgitation, a small pericardial effusion, and a 7-cm ascending aortic aneurysm. The diagnosis was established based on the characteristic echocardiographic appearance and elevated N-terminal pro-B-type natriuretic peptide levels. Notably, no routine cardiological surveillance had been performed following the diagnosis of CS. The patient was managed conservatively with intravenous diuretic therapy and optimization of heart failure treatment. Following multidisciplinary evaluation, surgical intervention was not pursued because of the patient's advanced disease stage, clinical instability, and concomitant ascending aortic aneurysm, which collectively rendered him a prohibitive surgical candidate. His clinical course was subsequently complicated by acute kidney injury with progressive renal dysfunction and anuria, and he ultimately died during hospitalization. This case highlights the importance of regular cardiovascular follow-up in patients with CS, as delayed recognition of cardiac involvement may lead to advanced and potentially irreversible valvular disease. Early detection remains crucial for timely intervention and may improve clinical outcomes.