Clinical and echocardiographic characteristics of neuroendocrine tumours and carcinoid heart disease: insights from a contemporary Canadian cohort

Background Neuroendocrine tumours (NETs) are uncommon cancers that secrete vasoactive hormones. Around half of metastatic small bowel NETs develop carcinoid syndrome and historically up to 50% develop carcinoid heart disease (CHD). We evaluated clinical characteristics, echocardiographic features, and outcomes of patients with NETs and CHD in a contemporary cohort to identify factors associated with CHD development and mortality. Methods We identified patients with NETs who underwent an echocardiogram at a tertiary cancer centre-affiliated laboratory (2013-2023). Patients were classified based on whether they developed CHD. Clinical characteristics, echocardiographic data within 6 months of NET diagnosis, treatments, and outcomes were compared between CHD and non-CHD patients. Results Over a 10-year period, 87 patients with NETs were identified (48% female; median age 61 years), with 18 (21%) developing CHD. Primary small bowel NETs were more common with CHD (83% vs. 55%, p =0.032). Patients with CHD exclusively had right-sided valve involvement: 100% tricuspid, 61% pulmonary, and 0% mitral/aortic; 17% had a patent foramen ovale. Compared to non-CHD patients, CHD patients demonstrated higher right atrial volume index and right ventricular (RV) basal diameter, with more frequent RV dysfunction. Patients with CHD had a lower median survival from the time of NET diagnosis (6.6 vs. 13.4 years; p =0.007). Among CHD patients, primary NET resection was associated with improved survival ( p =0.006). Conclusions Within a contemporary cohort, approximately 1 in 5 patients with NETs develop CHD, and exhibit only right-sided valve involvement. CHD was associated with increased mortality while primary NET resection was associated with improved survival.