Abstract 12391: The Extent of Myocardial Fibrosis Assessed With Cardiac Magnetic Resonance Correlates With Cardiac Troponin T Release in Patients With Nonischemic Heart Failure
Background: Persistent and modest elevation of serum cardiac troponin T (cTnT) is frequently observed and represents ongoing subclinical myocardial damage in heart failure (HF) patients. Recently, the presence of myocardial fibrosis assessed with cardiac magnetic resonance (CMR) and increased levels of cTnT predict poor prognosis in several cardiomyopathies. However the association between myocardial fibrosis and myocardial damage detected by cTnT is not fully evaluated. In this study, we investigated the correlation between the extent of myocardial fibrosis and the amount of cTnT release from nonischemic failing myocardium.
Methods and Results: We measured serum cTnT levels in aortic root (Ao) and coronary sinus (CS) using a highly sensitive assay (detection limit >5ng/L) in 68 nonischemic HF patients who underwent CMR. Transcardiac cTnT release was described as the differences between CS and Ao cTnT levels [ΔcTnT (CS-Ao)]. Myocardial fibrosis was quantified by the extent of late gadolinium enhancement (LGE) in CMR. cTnT was detectable in 62 patients (91%) and ΔcTnT (CS-Ao) levels were available [ΔcTnT (CS-Ao) >0 ng/L] in 55 patients (81%). LGE was observed in 38 patients (56%). LGE-positive patients were more frequently observed in available group (n=37: 67%) compared to unavailable group (n=1: 8%; P≤0.001). Among available patients, ΔcTnT (CS-Ao) levels were significant higher in LGE-positive patients [4.3 (2.3-5.5) ng/L] compared to LGE-negative patients [1.6 (1.1-2.7) ng/L; P≤0.001]. The extent of LGE positively correlated with log [ΔcTnT (CS-Ao)] levels (r=0.412, P=0.01). In contrast, transcardiac B-type natriuretic peptide levels did not correlate with the volume of LGE (r=0.286, P=0.10).
Conclusions: The extent of LGE correlates with cTnT release in nonischemic HF patients. These results suggest that increased levels of cTnT could reflect the presence and extent of myocardial fibrosis.
- © 2013 by American Heart Association, Inc.