Role of natriuretic peptides in the diagnosis and treatment of patients with carcinoid heart disease

Abstract

Carcinoid heart disease (CHD) occurs in 20-70% of the patients with metastatic well-differentiated neuroendocrine tumours (NET). We evaluated whether natriuretic peptides (ANP or NT-proBNP) are useful in early detection of CHD. Blood samples from 32 patients with NET were compared with cardiac ultrasound follow-up. CHD was defined as thickening of the tricuspid valve in the presence of grade III-IV/IV tricuspid valve regurgitation. CHD was found in nine out of 32 patients (28%), all with symptoms of the carcinoid syndrome compared to 65% in the 23 patients without CHD (P=0.04). Median levels of NT-proBNP and 5-HIAA were significantly higher in patients with CHD (894 ng l(-1) and 815 micromol 24 h(-1)) compared to those without (89 and 206 ng l(-1), P<0.001 and P=0.007). No significant differences were detected in ANP levels (P=0.11). Dilatation of the right atrium and ventricle as well as thickening of the tricuspid valve and degree of regurgitation were statistically significant correlated with NT-proBNP levels. The accuracy of NT-proBNP in the diagnosis of CHD was higher than that of ANP. A significantly better survival was observed in case of normal NT-proBNP values. In conclusion, NT-proBNP is helpful as a simple marker in the diagnosis of CHD. Survival is better in patients with normal levels of NT-proBNP.