Myeloid-related protein 8/14 and high-sensitivity cardiac troponin I to differentiate type 2 myocardial infarction

Myocardial infarction (MI) not only defines acute MI with obstructed coronary arteries (T1MI) but also myocardial necrosis caused by myocardial oxygen supply/demand mismatch as type 2 MI (T2MI); only T1MI patients benefit from an early invasive management. Myeloid-related protein(MRP)-8/14 is a biomarker described in various inflammatory diseases and in MI patients. Here we evaluate the potential of MRP-8/14 and high-sensitivity troponin I (hs-cTnI) to differentiate T2MI from T1MI. Patients with final diagnosis NSTEMI (n = 254; 33.1% female) enrolled in a prospective biomarker registry between 08/2011 and 10/2016 were analysed. Median baseline MRP-8/14 levels were higher in T2MI (n = 55; 3.37(1.88–6.48)μg/mL) than in T1MI (n = 199; 2.4 [1.4–3.79]μg/mL) (p = .013) patients, in contrast to hs-cTnI (T2MI:52[11.65–321.4]ng/L vs. T1MI:436.5 [61.25–1973.8]ng/L; p < .001). To detect the strength of this association odds ratios(OR) were calculated with MRP-8/14 yielding 2.13(1.16–3.92; p = .015) to predict T2MI and 0.47(0.26–0.87; p = .015) for T1MI. As expected, hs-cTnI yielded an OR of to predict T2MI 0.34(0.17–0.65; p = .001) and 2.98(1.53–5.81; p = .001) for T1MI. Both markers show comparable and independent results if adjust to hs-cTnI/MRP-8/14, TIMI risk score and CRP. T2MI is associated with higher MRP-8/14 and lower hs-cTnI concentrations than T1MI. Our data suggest that MRP-8/14 as a marker of inflammation might provide usable discriminatory information complementing hs-cTnI in a diagnostic procedure evaluating the type of MI directly upon hospital admission.