A Metabolomics Study of Thrombosis after Cardiac Surgery in Children with Congenital Heart Disease

Objective Thrombosis is a major complication after cardiac surgery in children with congenital heart disease (CHD). The mechanisms underlying thrombosis development remain poorly understood. We aimed to identify novel circulating metabolites before cardiac surgery that are associated with the development of thrombosis after surgery in children with CHD. Approach and results 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 CHD 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 (FDR) correction for multiple comparison and adjustment for clinical characteristics; elastic net regression was used to select a prediction model. Out of 1,115 metabolites measured in samples from 203 children, 776 met the quality control criteria. In total, 26 children (12.8%) developed thrombosis. Among the 776 metabolites, 195 were significantly associated with thrombosis (FDR q-value < 0.05). The top three metabolites showing the strongest associations with thrombosis were eicosapentaenoate, steroid monosulfate C19H28O6S, and formiminoglutamate (FDR = 0.01 for all). Pathway analysis showed that the pathways of nicotinate and nicotinamide metabolism (P = 0.0007) and glycerophospholipid metabolism (P = 0.002) were enriched and had significant impacts 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 0.94 in the training sample (70% of the total sample) and 0.84 in the testing sample (the remaining 30%). Conclusion We have identified promising novel metabolites and metabolic pathways associated with thrombosis. Future studies are warranted to confirm the findings and examine the mechanistic pathways to thrombosis.