Abstract 13293: Acyl-coa Binding Protein is Marker of Myocardial Ischemia
Background: We recently applied a liquid chromatography tandem mass spectrometry (LC-MS/MS) based proteomics platform to plasma samples from individuals undergoing a “planned” myocardial infarction (PMI; alcohol ablation for hypertrophic cardiomyopathy) and identified acyl-CoA binding protein (ACBP) as a potential circulating biomarker of myocardial injury. ACBP is a 10 kDa intracellular protein that is highly expressed in cells with a high turn-over of fatty acids such as cardiomyocytes. We sought to determine the site of ACBP release and whether ischemia alone is sufficient to trigger an increment in plasma levels in humans.
Methods: Coronary sinus (CS) and peripheral venous samples were obtained simultaneously from PMI patients; peripheral venous samples were obtained from derivation/validation cohorts of subjects undergoing cardiac stress testing. Plasma ACBP levels were measured by immunoassay.
Results: In PMI patients (n=11), pre-injury levels of ACBP were comparable in the CS and peripheral samples. As early as 10 min after PMI, ACBP levels were 27% higher in the CS than in the periphery (P = 0.01), and remained 30% higher at 60 minutes (P = 0.02). Next, we studied 105 patients undergoing cardiac stress testing, 52 of whom demonstrated inducible ischemia (cases) and 53 of whom did not (controls). Baseline ACBP levels were comparable in cases and controls. Changes in median ACBP levels after the exercise stress challenge were significantly greater in the ischemic patients (cases) than in the controls (22% increase in cases; 1% decrease in controls; P = 0.0001), findings which were validated in a second cohort of 101 patients subjects (P = 0.002). These findings remained significant in a multivariable model adjusting for age, male sex, diabetes, BMI, smoking, creatinine, hypercholesterolemia, and total minutes of exercise. By contrast, the effects of exercise on established biomarkers (cTnI, NT-proBNP and FABP) did not differ betwen cases and controls.
Conclusions: We provide initial verification that ACBP is rapidly released from the injured heart and increases in response not only to infarction but also ischemia. These findings motivate additional clinical studies of this novel biomarker in heterogeneous patient cohorts.
Author Disclosures: X. Shi: None. G. Lewis: None. M. Keyes: None. L. Farrell: None. S. Carr: None. H. Keshishian: None. M. O’Donoghue: None. M. Sabatine: None. R. Gerszten: None.
This research has received full or partial funding support from the American Heart Association.
- © 2014 by American Heart Association, Inc.