Abstract 16830: Early Cardiac Biomarker Changes Following Myocardial Injury

Abstract

Introduction: Levels of cardiac troponin I (cTnI), now used routinely to identify myocardial infarction, typically rise slowly following an acute myocardial injury (AMI), and early detection remains challenging, as does early identification of large AMI events that may benefit most from early invasive management. Methods and Results: Plasma samples were obtained preceding and at frequent intervals following septal myocardial ablation (PTSMA) in HCM patients (n = 20) to identify putative early cardiac biomarkers (CBs). Immunoassays for CBs of interest were developed and validated. Three CBs with markedly different time-dependent profiles following AMI were identified (Figure 1): cTnI rose slowly and peaked late (16-24h); fatty acid binding protein 3 (FABP3) rose and peaked much earlier (4-6h); while myosin light chain 3 (MYL3) peaked and declined very rapidly (<2h). Quantification of time-dependent changes in the levels of CBs, d[CB]/dt and d2[CB]/dt2, revealed dynamic early signals with the potential to time the onset and course of injury (Figure 2). Conclusions: These data demonstrate significantly different time courses for increased plasma levels of CBs following an AMI event. While cTnI is the most cardiac specific, MYL3 and FABP3 levels, as well as changes in levels of all 3 CBs, provide additional early information that may allow for improved ability to diagnose AMI at earlier time points, as well as to identify time elapsed since the AMI event. Such analyses of novel CBs and their rapid changes may enhance early identification of AMI and help distinguish larger AMIs that could benefit most from early intervention.