Abstract 16034: Modeling the Early Inflammatory Response to Myocardial Infarction in Man: Release Kinetics of Inflammatory Biomarkers in Patients Undergoing Transcoronary Ablation of Septal Hypertrophy
Background: Inflammatory biomarkers in patients with acute myocardial infarction (AMI) have been linked to risk stratification in terms of long-term morbidity and mortality. However, the release kinetics of inflammatory biomarkers in the setting of human AMI has been difficult to establish.
Methods: We analyzed the release kinetics of C-reactive protein measured by the 3rd generation and high-sensitivity assays, interleukin 6 (IL-6) and interleukin 18 (IL-18) in consecutive patients (n=21) undergoing TASH for hypertrophic obstructive cardiomyopathy, a procedure that mimics the conditions present during AMI. Blood samples were collected prior to TASH (baseline , BL) and 15, 30, 45, 60, 75, 90, and 105 minutes and 2, 4, 8, and 24 h after TASH. CRP, hs-CRP and IL-6 were quantified in serum, and IL-18 was quantified in plasma using immunoassays. Peripheral blood leukocyte subset kinetics was analyzed in 10 patients using single-platform flow cytometry assays.
Results: CRP concentrations measured by the hs-assay were significantly increased at 8 h (2.68 mg/L [IQR 1.23-11.80] vs. 2.17 mg/L [IQR 1.15-5.06] at BL; P=0.002). In comparison, CRP concentrations measured by the 3rd generation assay increased significantly at 24 h (1.0 mg/L [IQR 0.7-1.75] vs. 0.2 mg/L [IQR 0.1-1.05] at BL; P<0.001). IL-6 concentrations were significantly increased at 45 min (2.59 pmol/L [IQR 1.69-5.0] vs. 1.5 pmol/L [IQR 1.5-2.21] at BL; P=0.002) with a continuous rise during further time points. IL-18 concentrations showed a significant rise at 15 min (365 pg/mL [IQR 321-408] vs. 318 pg/mL [IQR 296-378] at BL; P<0.05) followed by a rapid normalization of its plasma levels. Elevated counts of polymorphonuclear neutrophils were detectable already at 15 min, with significant increase starting at 2 h (6496 cells/μl vs. 4566 cells/μl at BL; P=0.004). Among monocytic cells, CD14highCD16neg (‘classical’) monocytes started to increase at 8 h, with the development of significant monocytosis at 24 h (P=0.015 vs. BL).
Conclusions: IL-6 and neutrophil granulocytes showed a continuous rise at all pre-specified time points after induction of myocardial infarction. Our results provide valuable additional evidence for the diagnostic value of inflammatory biomarkers in the early setting of AMI.
- © 2013 by American Heart Association, Inc.