Effect of heparin administration on metabolomic profiles in samples obtained during cardiac catheterization.

BACKGROUND Metabolic profiling holds promise for early detection of coronary artery disease and assessing risk for ischemic events. Heparin is frequently administered (1) to treat acute coronary syndromes; and (2) during routine cardiac catheterization procedures. Because it stimulates lipolysis, heparin is a potential confounder of metabolic profiling in these populations. METHODS AND RESULTS Using mass spectrometry and conventional immunoassays, we evaluated how unfractionated heparin administration affected 69 peripheral blood metabolites (acylcarnitines, amino acids, nonesterified fatty acids and their oxidation byproducts, conventional lipids, glucose, and C-reactive protein) in samples obtained pre- and postcardiac catheterization from 19 patients who received heparin and 10 patients who did not. Using unpaired t tests, we compared the changes in mean metabolite levels before and after the procedure between the nonheparin and heparin groups. Clinical characteristics of the nonheparin and heparin groups, indication for cardiac catheterization, procedure performed, and other periprocedural variables were similar. The mean change between pre- and postprocedure β-hydroxybutyrate (5.43 versus 66.84 μmol/L; P=0.009), ketones (21.17 versus 98.49 μmol/L; P=0.009), nonesterified fatty acids (0.37 versus 1.20 mmol/L; P=0.017), and triglycerides (-9.33 versus -36.50 mg/dL; P=0.007) was significantly different between the nonheparin and heparin groups, respectively. There were no significant differences between groups in the other metabolites measured. CONCLUSIONS Heparin administration during cardiac catheterization induced changes in peripheral blood metabolites that were consistent with known lipolytic effects of heparin and define a metabolite signature associated with heparin administration. These findings are important for accurate interpretation of future metabolic profiling studies in populations exposed to heparin.