Abstract 13079: Reduced Apoj-Glyc Serum Levels Identify Patients With Cardiac Ischemic Events Among Those Attending the Emergency Department With Chest Pain

Abstract

Introduction: Glycosylated apolipoprotein J (ApoJ-Glyc) has been suggested to be a marker for the early detection of myocardial ischemia. Ischemia induces an intracellular accumulation of non-glycosylated ApoJ that mirrors a reduction in ApoJ-Glyc serum concentration in acute ischemic syndromes. Objective: The EDICA clinical trial - multi-centre, international, diagnostic study (NCT04119882)- was carried out to assess the performance of ApoJ-Glyc as a biomarker for the early detection of myocardial ischemia in patients attending the A&E department with chest pain suggestive of acute coronary syndrome (ACS). Methods: EDICA assessed 404 patients. Blood samples were obtained on admission, for assessment of high sensitivity-troponin (hs-Tn) and ApoJ-Glyc. ApoJ-Glyc serum levels were analyzed with a novel ELISA, targeting a specific glycosylated variant of ApoJ (ApoJ-GlycA6). Results: Based on clinical diagnostic tests, 291 patients were given a final diagnosis of “non-ischemic” event and 113 patients were considered to have had an ischemic event (33 STEMI, 48 NSTEMI, 27 Unstable Angina and 5 “unclassifiable” ACS). ApoJ-GlycA6 levels were significantly lower on admission in ischemic patients, compared with non-ischemic patients (66 [46-90] vs. 73 [56-95] μg/ml, respectively; P=0.04). Ischemic patients who underwent PCI and had a pre-PCI TIMI 0-2 flow showed significantly lower ApoJ-GlycA6 levels at admission compared with non-ischemic patients (64 [37-81] vs. 73 [56-95] μg/ml; P=0.01). Of interest, 51% of ischemic patients, had “inconclusive” or negative hs-Tn at admission. Among these, ApoJ-GlycA6 identified the ischemic event in 48% (<66 μg/ml). Conclusions: ApoJ-Glyc concentration decreased in patients with documented myocardial ischemia, compared with patients with a final diagnosis of “non-ischaemic” event. Patients with reduced TIMI flow indicative of poorer myocardial perfusion were among those with the lowest ApoJ-Glyc concentration. ApoJ-Glyc was low in ischemic patients irrespective of hs-Tn concentration. The results confirm the potential role of ApoJ-Glyc as a biomarker for the early detection of cardiac ischemia that could provide complementary information to that afforded by current biomarkers and diagnostic tests.