Cardiomyopathy
Usefulness of High-Sensitivity Cardiac Troponin T and Brain Natriuretic Peptide as Biomarkers of Myocardial Fibrosis in Patients With Hypertrophic Cardiomyopathy

https://doi.org/10.1016/j.amjcard.2013.04.060Get rights and content

Myocardial fibrosis assessed by late gadolinium enhancement cardiac magnetic resonance imaging is associated with cardiovascular events in patients with hypertrophic cardiomyopathy (HC), but few data are available regarding the utility of biomarkers for detecting late gadolinium enhancement. The aim of this study was to examine serum levels of myoglobin, cardiac myosin light chain I, high-sensitivity cardiac troponin T (hs-cTnT), and creatine kinase-MB isoenzyme and plasma levels of brain natriuretic peptide (BNP) in relation to late gadolinium enhancement in 53 patients with HC. Levels of hs-cTnT and BNP were higher in 23 patients with late gadolinium enhancement than in 30 patients without it (p <0.01 for both). An hs-cTnT level ≥0.007 ng/ml or a BNP level ≥70 pg/ml had good diagnostic value for detecting late gadolinium enhancement, with sensitivity of 96% or specificity of 90% with the combination of these 2 biomarkers. The extent of late gadolinium enhancement was correlated with BNP level (p <0.01) but not with hs-cTnT level in 23 patients with HC with late gadolinium enhancement. The increase in the extent of late gadolinium enhancement was related to hs-cTnT level in 8 patients during 22 months of follow-up (p = 0.02). In conclusion, the combination of hs-cTnT and BNP is useful in detecting myocardial fibrosis in patients with HC. The findings of this study indicate that hs-cTnT is a direct marker of ongoing myocardial fibrosis and that BNP is a marker of left ventricular overload partially associated with myocardial fibrosis.

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Methods

The present study consisted of consecutive patients with HC who were referred to our institute for gadolinium-enhanced myocardial resonance imaging from March 2010 to March 2013. The diagnosis of HC was based on the conventional echocardiographic demonstration of left ventricular end-diastolic thickness ≥15 mm and left ventricular end-diastolic diameter ≤55 mm in the absence of any cardiac or systemic disorder that could cause hypertrophy, such as severe hypertension or aortic stenosis.

Results

Late gadolinium enhancement was detected in 23 of 53 patients (43%). The location of late gadolinium enhancement was the anterior ventricular septum–free wall junction in 12 patients (23%), the ventricular septum in 11 (21%), the apical area in 9 (17%), the posterior ventricular septum–free wall junction in 4 (8%), the anterior wall in 4 (8%), the posterior wall in 2 (4%), and the lateral wall in 1 (2%). Late gadolinium enhancement was associated with younger age, a lower left ventricular

Discussion

The present study showed that higher levels of serum hs-cTnT and plasma BNP were associated with late gadolinium enhancement on magnetic resonance imaging in patients with HC. Furthermore, a level of hs-cTnT ≥0.007 ng/ml or BNP ≥70 pg/ml had good diagnostic value for the detection of late gadolinium enhancement, with sensitivity of 96% or specificity of 90% with the combination of the 2 biomarkers. These findings indicate that the combined measurement of hs-cTnT and BNP could be a favorable

Disclosures

The authors have no conflicts of interest to disclose.

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