Association Between Activin A & NT-pro-BNP in Carcinoid Heart Disease and Intestinal Desmoplasia in Patients with Metastatic Midgut and Pelvic NET.

Introduction: Carcinoid heart disease (CHD) involves cardiac valvular fibrosis and volume overload. N-terminal pro-brain natriuretic peptide (NT-pro-BNP) is released by the myocardium in response to increased wall stress in CHD. Activin A is a member of the TGF-β superfamily involved in fibrogenesis. Aim(s): To compare Activin A and NT-pro-BNP as biomarkers for detecting CHD and to determine the utility of Activin A as a biomarker in CHD and NET-related desmoplasia. Materials and methods: Plasma samples from 56 patients with metastatic midgut or pelvic NET were analyzed using ELISA. All patients underwent echocardiography and abdomino-pelvic CT. Results: Twenty-four patients had CHD alone, 17 had desmoplasia alone and 15 had neither fibrotic process. CHD patients had significantly higher levels of NT-pro-BNP (p<0.0001) and Activin A (p=0.005) than those without CHD. No difference in peripheral plasma Activin A levels was observed in patients with desmoplasia or without any fibrotic process (p=0.417). NT-pro-BNP ≥ 15.2 pmol/L had a sensitivity of 91.7% and specificity of 59.4% for detecting CHD (AUC 0.868). Plasma Activin A ≥ 0.35 ng/mL had a sensitivity of 91.7% and specificity of 21.9% for detecting CHD (AUC 0.729). Conclusion: Plasma NT-pro-BNP and Activin A are both significantly associated with the presence of CHD, conferring utility as biomarkers for this pathology. Peripheral plasma Activin A, however, is not a useful biomarker to detect desmoplasia. [ABSTRACT FROM AUTHOR]