Myocardial Entropy and Risk Predictors in Hypertrophic Cardiomyopathy: An Analysis From the NHLBI HCM Registry
Panagiotis Antiochos1,2, Yin Ge1, Michael Jerosch-Herold1
1Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA (P.A., Y.G., M.J.-H., L.-P.D., C.Y.H., R.Y.K.).
Insights
Left ventricular (LV) entropy, a novel measure in hypertrophic cardiomyopathy (HCM), correlates with adverse outcomes and predicts ventricular tachycardia. This imaging biomarker offers valuable clinical insights for HCM patient risk stratification.
Area of Science:
- Cardiology
- Biomedical Imaging
- Biomarkers
Background:
- Hypertrophic cardiomyopathy (HCM) is a complex genetic heart disease.
- Assessing risk predictors in HCM is crucial for patient management.
- Novel imaging biomarkers are needed to improve risk stratification.
Purpose of the Study:
- To investigate the associations of left ventricular (LV) entropy with risk predictors in patients with HCM.
- To determine if LV entropy can predict adverse outcomes in HCM.
- To evaluate the clinical utility of LV entropy in HCM patient care.
Main Methods:
- LV entropy was calculated from cardiovascular magnetic resonance imaging (CMR) using pixel signal intensities of the LV myocardium.
- Entropy values were correlated with demographic, genetic, imaging, and serum biomarkers.
- Associations with European Society of Cardiology (ESC) risk score and Holter recordings were analyzed.
Main Results:
- LV entropy showed significant associations with sarcomere mutations, ventricular tachycardia, atrial fibrillation, elevated cardiac troponin T (cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP).
- LV entropy correlated with increased LV wall thickness, LGE presence/extent, extracellular volume, atrial size/function, and myocardial strain.
- LV entropy was the strongest predictor of ventricular tachycardia on Holter, independent of LGE presence.
Conclusions:
- LV entropy is associated with clinical, imaging, and biological predictors of adverse outcomes in HCM.
- LV entropy provides valuable prognostic information, independent of LGE.
- LV entropy is a powerful predictor of ventricular tachycardia in HCM patients.
Background:
Entropy, a novel measure of myocardial tissue heterogeneity by cardiovascular magnetic resonance imaging, may have clinical value in patients with hypertrophic cardiomyopathy (HCM). We aimed to investigate the associations of entropy with risk predictors in HCM, using the National Heart, Lung, and Blood Institute HCM Registry.
Methods:
Entropy values were calculated using the probability distribution of pixel signal intensities of the left ventricular (LV) myocardium on the late gadolinium enhancement (LGE) short-axis stack images. Entropy values were correlated with demographic, genetic, imaging, and serum biomarkers as well as ambulatory Holter recordings and the European Society of Cardiology risk score of sudden cardiac death at 5 years.
Results:
Among 1736 patients with HCM, LV entropy demonstrated significant associations with sarcomere mutations, history of ventricular tachycardia, atrial fibrillation, and elevation of cTnT (cardiac troponin T) and NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels (P<0.001). Furthermore, LV entropy demonstrated an association with increased maximal LV wall thickness, LGE presence and extent, higher extracellular volume, left atrial area and function, myocardial strain (P<0.001), and was positively correlated with higher values of the European Society of Cardiology risk score (P<0.001). In the subgroup of patients without LGE (n=858), entropy values remained significantly associated with a history of ventricular tachycardia, increased maximal wall thickness, decreased myocardial strain, and the European Society of Cardiology risk score (P<0.05 for all). In both the whole cohort and in patients without LGE, LV entropy was the strongest predictor of ventricular tachycardia on Holter (odds ratio [95% CI] 1.59 [1.33-1.90]; 1.87 [1.28-2.74] respectively, P<0.001 for both).
Conclusions:
In patients with HCM, LV entropy demonstrated associations with clinical, imaging, and biological predictors of adverse outcomes independent of LGE presence and was the strongest predictor of ventricular tachycardia on Holter.
Registration:
URL: https://www.clinicaltrials.gov; Unique identifier: NCT01915615.
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