Elevated plasma endocan and BOC in heart failure patients decrease after heart transplantation in association with improved hemodynamics

BACKGROUND: The prevalence of heart failure (HF) is rising with ageing population and constitutes a major health problem globally. A common complication of HF is pulmonary hypertension (PH) which negatively impacts survival. A pathophysiological association between HF and PH with tumorigenic processes has been suggested. We aimed to identify the plasma levels of, and the association between tumour-related proteins and hemodynamic improvements in patients with HF and PH due to left heart disease (LHD) before and 1-year after heart transplantation (HT). METHODS: Forty-eight tumour-related proteins were measured with proximity extension assay in plasma from 20 controls and 26 HF patients before and 1-year after HT. Patients’ hemodynamics were measured with right heart catheterization. RESULTS: Out of 48 proteins, specifically, plasma levels of endocan and brother of CDO (BOC) were elevated in end-stage HF patients compared to controls (p < 0.001), but decreased after HT (p < 0.01), towards controls’ levels. The decrease of endocan levels after HT correlated with improved mean pulmonary arterial pressure (r(s) = 0.80, p < 0.0001), pulmonary arterial wedge pressure (r(s) = 0.63, p = 0.0012), and pulmonary vascular resistance (r(s) = 0.70, p < 0.001). The decrease and normalization of BOC after HT correlated with decreased mean right atrial pressure (r(s) = 0.61 p = 0.0015) and NT-proBNP (r(s) = 0.57, p = 0.0022), as well as increased cardiac index (r(s) = − 0.51, p = 0.0086) and left-ventricular stroke work index (r(s) = − 0.57, p = 0.0039). CONCLUSION: Our results suggest that (i) plasma endocan in HF may reflect the state of pulmonary vascular congestion and PH-LHD, whereas (ii) plasma BOC may reflect the cardiac function and the hemodynamic overload in HF. The exact role of these proteins and their clinical applicability as biomarkers in HF and PH-LHD ought to be investigated in larger cohorts. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00380-020-01656-3) contains supplementary material, which is available to authorized users.