Cardiomyocyte injury induced by hemodynamic cardiac stress

Objective: We explored whether hemodynamic cardiac stress leads to a differential release of cardiomyocyte injury biomarkers, used in the diagnosis of acute myocardial infarction (AMI). Methods: In an observational international multicenter study, we enrolled 831 unselected patients presenting with symptoms suggestive of AMI to the emergency department. The final diagnosis was adjudicated by two independent cardiologists. Hemodynamic cardiac stress was quantified by levels of B-type natriuretic peptide (BNP). Spearman's rho correlation was used to analyze the correlations between BNP and high-sensitivity cardiac troponin T (hs-cTnT), Siemens cTnI-Ultra (cTnI-ultra), CK-MB and Myoglobin. Patients were categorized according to the extent of hemodynamic cardiac stress as quantified by BNP tertiles. Results: Among all patients, the positive pair-wise correlation with BNP was strongest with hs-cTnT and cTnI-ultra (r = 0.58 and 0.50, respectively), moderate for Myoglobin (r = 0.43), and weakest with CK-MB (r = 0.25; p < 0.001 for each). Similar pattern of correlations was also observed among AMI patients. Among patients diagnosed with non-cardiac cause of chest pain (n = 385, 46%) and cardiac but non-coronary (n = 109, 13%), BNP had significant positive correlations with hs-cTnT, cTnI-ultra and Myoglobin (p < 0.05), but not with CK-MB (p = NS). A similar pattern of stronger correlation between BNP and hs-cTnT, cTnI-ultra and Myoglobin as compared to that with CK-MB was also observed within the higher BNP tertile range. There was no correlation between BNP and other biomarkers within the 1st BNP tertile group. Conclusion: Hemodynamic cardiac stress, as quantified by BNP, as a likely cause of cardiomyocyte injury, is more closely reflected by concentrations of hs-cTnT, cTnI-ultra and Myoglobin than CK-MB.