Postprandial variability of novel heart failure biomarkers in Fontan patients compared to healthy volunteers

Abstract Background Blood-based biomarkers reflecting different components of cardiovascular pathophysiology are now used increasingly in patients with Fontan circulation due to univentricular congenital heart disease. Feeding alters haemodynamics significantly and, thus, may affect biomarker levels. As the haemodynamic responses to a meal differ between Fontan patients and normal subjects, we hypothesised that biomarker kinetics may also vary between these populations. Methods In 15 patients with Fontan physiology, and 15 matched healthy volunteers, 4 heart failure biomarkers were measured under fasting conditions, and 3 after additional timepoints over 2 h following ingestion of a standardised liquid meal. Changes in biomarker levels over time and the effect of Fontan physiology, sex and age were tested using repeated-measures mixed models. Results Under fasting conditions, high-sensitivity C-reactive protein (hsCRP), mid-regional pro-adrenomedullin (MR-proADM) and C-terminal pro-endothelin-1 (CT-proET-1) were raised significantly in Fontan patients compared to controls. Postprandially, mid-regional pro-atrial natriuretic peptide (MR-proANP) decreased significantly in patients (max. mean decrease ∼7% after 120 min). Conversely, it increased in normal subjects (max. mean increase ∼8% after 60 min). The remaining biomarkers did not change significantly. Conclusions The ingestion of food triggers contrary deflections of MR-proANP levels in patients with Fontan circulation compared to normal subjects. Therefore, this parameter should be assessed under fasting conditions in order to correct for postprandial variability.