Background: Patients with carcinoid syndrome (CS) may present carcinoid heart disease (CHD) but prognostic factors are not entirely understood.

Patients and Methods: Retrospective study of patients with metastatic neuroendocrine tumours (NETs) and CS and/or abnormal 24-hoururinary 5-hydroxiindolacetic acid. CHD was defined as moderate to severe tricuspid or pulmonary regurgitation in the echocardiogram.

Results: The frequency of CHD among 42 patients was 38% (95% confidence interval [CI]: 23%–54%). CHD was associated with higher volume of liver metastases (odds ratio [OR] 13.86, 95% CI: 2.57–74.68, p = 0.002). Time from CS symptoms to NET diagnosis was borderline significant (p = 0.08). When CHD was defined as at least mild tricuspide regurgitation, the frequency of CHD was 45% and it was associated with cardiovascular comorbidities (OR: 6.58, 95% CI: 1.09; 39.78, p = 0.040).

Conclusion: CHD was frequent among patients with CS, significantly associated with high liver tumour burden, and likely linked to the history of cardiovascular disease and longer time of CS.