Abstract 12590: Usefullness of Early Release Peak of Cardiac Biomarkers for Detection of Myocardial Infarction Related to Coronary Revascularization Procedures. A Cardiac Magnetic Resonance Study

Background: The elevation of troponin (TnI) and creatine kinase-MB (CKMB) after coronary revascularization procedures is frequent, but may not be reliable at identifying a definitive procedure-related myocardial injury. Cardiac magnetic resonance (CMR) is the gold standard in the identification of small areas of myocardial necrosis by late gadolinium enhancement (LGE). The presence of a biomarker early release peak might indicate a nonlethal transient cellular myocardial damage and help to discriminate the patients without procedure-related myocardial lesion. Thus, our objective was to evaluate the amount and pattern of release of biomarkers after coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) compared with the area of new LGE on CMR. Methods: Patients with indication for coronary revascularization were included. Measurements of high-sensitivity TnI and CK-MB were obtained before and after the procedures, every 6 hours until 48 hours after PCI, and up to 72 hours after CABG. We evaluated the area under the curve (AUC) and peak release of biomarkers and stratified before and 24 hours after the procedure. CMR was performed before and after procedures with quantification of necrosis by LGE. Results: From 150 patients who completed the study, 60 (40%) underwent CABG with cardiopulmonary bypass (CPB), 44 (29.3%) without CPB, and 46 (30.7%) underwent PCI. 130 (86.7%) exhibited release of cardiac biomarkers consistent with myocardial injury, however only 32 (21.3%) had new LGE on CMR. The AUC and peak release of TnI showed a moderate correlation with the mass of new myocardial LGE on CMR (AUC: r = 0.46, P < 0.0001; TnI peak: r = 0.45, P < 0.0001), as well as the AUC and peak release of CKMB (AUC: r = 0.33, P < 0.0001; CK-MB peak: r = 0.35, P <0.0001). Patients without new LGE on CMR had more frequently an early peak release of cardiac biomarkers when compared with those with new LGE: 63 (88.7%) vs. 8 (11.3%), P = 0.004. Conclusion: The elevation of cardiac biomarkers after coronary revascularization procedures had a low diagnostic power for the detection of new myocardial areas of infarction identified by LGE on CMR. The early release of biomarkers may be useful to rule out the diagnosis of peri-procedural myocardial infarction.