Soluble Lectin-Like Oxidized Low-Density Lipoprotein Receptor-1 as an Early Biomarker for ST Elevation Myocardial Infarction - Time-Dependent Comparison With Other Biomarkers

Background: The diagnostic sensitivity of myocardial necrosis markers, such as creatine kinase-MB (CK-MB), cardiac troponins, myoglobin and heart-type fatty acid-binding protein (H-FABP) for the earliest stage of ST-elevation myocardial infarction (STEMI), remains insufficient. We compared a new biomarker of plague vulnerability (soluble lectin-like oxidized low-density lipoprotein receptor-1, sLOX-1) with other biomarkers at the earliest stage of STEMI. Methods and Results: Plasma sLOX-1 levels were measured in 125 STEMI, 44 non-STEMI (NSTEMI) and 125 non-acute myocardial infarction (non-AMI) patients and were significantly (P<0.0001) higher in the STEMI and NSTEMI than in the non-AMI patients (median, 25th and 75th percentiles: 241.0, 132.3 and 472.2 vs. 147.3, 92.9 and 262.4 vs. 64.3, 54.4 and 84.3 pg/ml, respectively). At the optimal cut-off value of 91.0 pg/ml, sLOX-1 discriminated STEMI from non-AMI with 89.6% sensitivity and 82.4% specificity. Time-dependent changes in sLOX-1, H-FABP, myoglobin, troponin T and CK-MB were analyzed in 27 STEMI patients. Elevated plasma sLOX-1 levels persisted for 24h after admission, whereas other markers were not elevated at the time of admission and peaked at >= 2 h thereafter. The diagnostic sensitivity of sLOX-1, H-FABP, myoglobin, troponin T and CK-MB for STEMI upon admission (89min after onset) was 93%, 78%, 70%, 56% and 33%, respectively. Conclusions: Plasma sLOX-1 diagnosed the early stages of STEMI more accurately than H-FABP, myoglobin, troponin T and CK-MB. (Circ J 2011; 75: 1433-1439)