Abstract 10535: Usefulness of Serum Cardiac Troponin T and I to Predict Cardiac Molecular Changes and Dysfunction in Patients with Hypertrophic Cardiomyopathy
Introduction: Serum cardiac troponin T (cTnT) could be a reliable indicator of myocardial remodeling, a proposed prognostic marker in hypertrophic cardiomyopathy (HCM). Meanwhile, cardiac troponin I (cTnI) has also been reported as a prognostic indicator in patients with chronic heart failure. However, the relationship between cardiac function, cTnT and cTnI has remained unclear in patients with HCM.
Hypothesis: We assessed the hypothesis that serum cTnT and cTnI could be related to ongoing myocardial damage in patients with HCM.
Methods: We checked serum cTnT and cTnI in 73 consecutive HCM patients in stable condition. All patients underwent cardiac catheterization and we calculated the maximum first derivative of left ventricular pressure (LV dP/dtmax) as an index of contractility and the LV pressure half-time (T1/2) as an index of isovolumic relaxation. In addition, to examine transcardiac utilization of troponin T and I, we measured serum cTnT and cTnI in the aortic root (Ao) and coronary sinus (CS). Endomyocardial biopsy specimens were obtained for gene expression assays.
Results: We divided the patients into two groups [group A: cTnT <0.008ng/ml, (n = 35), group B: cTnT group ≥0.008ng/ml, (n = 38)], on the basis of median value of cTnT in the peripheral vein. Brain natriutretic peptide, serum cTnI, left ventricular mass index, and T1/2 were significantly higher; LV ejection fraction was significantly lower in the group B than those in the group A. Moreover, mRNA level of cTnT was significantly correlated with mRNA levels of sarco-endplasmic reticulum Ca2+- ATPase and cytochrome c oxidase subunit 5B (r = 0.486, r = 0.404, respectively). Meanwhile, there was a significantly positive correlation between the transgradient of serum cTnIs calculated by the difference of CS and Ao and mRNA levels of Troponin I (r = 0.515, P = 0.009).
Conclusions: In conclusions, these findings indicate that elevated peripheral blood cTnT might be associated with cardiac dysfunction, resulting from the impairment of Ca2+-handling protein and mitochondrial function. Meanwhile, transcardiac gradient of cTnI levels may reflect ongoing myocardial damage in stable patients with HCM.
- © 2011 by American Heart Association, Inc.