Huntley, Marnie T.

Abstract Background Coagulation markers are used to guide clinical anticoagulation decisions. We aimed to identify circulating metabolites that are associated with coagulation markers in children with congenital heart disease (CHD). Methods Plasma samples were separated from whole blood under consistent conditions. Untargeted metabolomic data were measured in plasma from up to 203 young patients (age range: 0 days-24 years) with CHD before cardiac surgery. Coagulation markers included activated partial thromboplastin time (aPTT), prothrombin time (PT), and activated clotting time (ACT). Weighted Gene Co-expression Network Analysis (WGCNA) was performed to explore metabolite modules (clusters). Associations of metabolites with the coagulation markers were assessed cross-sectionally with regression models, with false discovery rate (FDR) correction for multiple comparison. Associations between coagulation markers and ‘eigenmetabolites’ from WGCNA modules were assessed by correlation analysis. Results A total of 776 metabolites were included in the final analysis. Among these, 20 metabolites were associated with PT and one (valine) with ACT (FDR q value < 0.05). Among the metabolites associated with PT, the top three were retinol, 1-palmitoyl-GPI (16:0), and X-25371 (identity unknown). One module from WGCNA with metabolites from the lipid super pathway was correlated with PT (P = 0.004). Conclusion In this first attempt to identify novel metabolites for coagulation markers, we report 21 metabolites associated with PT or ACT in children with CHD. Future studies are needed to replicate these findings in independent cohorts and to elucidate the biological mechanisms linking these metabolites to hemostatic regulation.

BACKGROUND: Thrombosis is a major complication after cardiac surgery in children with congenital heart disease. The mechanisms underlying thrombosis development remain poorly understood. We aimed to identify novel circulating metabolites before cardiac surgery that are associated with thrombosis after surgery in children with congenital heart disease. METHODS: In this prospective cohort study, all blood samples were drawn right before surgical incision and after the induction of anesthesia, and plasma was separated immediately under 4 °C. Untargeted metabolomic data were measured by Metabolon in plasma from children (age range, 0 days–18 years) with congenital heart disease undergoing cardiac surgery. The primary outcome was thrombosis within 30 days of surgery or before discharge. Associations of individual metabolites with thrombosis were assessed with logistic regression with false discovery rate correction for multiple comparison and adjustment for clinical characteristics; elastic net regression was used to select a prediction model. RESULTS: Out of 1115 metabolites measured in samples from 203 children, 776 met the quality control criteria. In total, 25 children (12.3%) developed thrombosis. Among the 776 metabolites, 175 were significantly associated with thrombosis (false discovery rate Q <0.05). The top 3 metabolites showing the strongest associations with thrombosis were eicosapentaenoate, stearidonate, and andro steroid monosulfate C 19 H 28 O 6 S (false discovery rate, 0.01 for all). Pathway analysis showed that the pathways of nicotinate and nicotinamide metabolism and glycerophospholipid metabolism were enriched (false discovery rate, 0.003 for both) and had significant impact on the development of thrombosis. In elastic net regression analysis, the area under the receiver operating-characteristic curve of a prediction model for thrombosis was 0.969 in the training sample (70% of the total sample) and 0.833 in the testing sample (the remaining 30%). CONCLUSIONS: We have identified promising novel metabolites and metabolic pathways associated with thrombosis. Future studies are warranted to confirm these findings and examine the mechanistic pathways to thrombosis.