Entropy as a Measure of Myocardial Tissue Heterogeneity in Patients With Ventricular Arrhythmias

Panagiotis Antiochos; Yin Ge; Rob J van der Geest; Chaitanya Madamanchi; Iqra Qamar; Ayako Seno; Michael Jerosch-Herold; Usha B Tedrow; William G Stevenson; Raymond Y Kwong

doi:10.1016/j.jcmg.2021.12.003

Entropy as a Measure of Myocardial Tissue Heterogeneity in Patients With Ventricular Arrhythmias

JACC Cardiovasc Imaging. 2022 May;15(5):783-792. doi: 10.1016/j.jcmg.2021.12.003. Epub 2022 Feb 16.

Affiliations

¹ Noninvasive Cardiovascular Imaging Program, Cardiovascular Division of Department of Medicine and Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts, USA; Cardiovascular Division, University Hospital of Lausanne (CHUV), Lausanne, Switzerland.
² Noninvasive Cardiovascular Imaging Program, Cardiovascular Division of Department of Medicine and Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts, USA.
³ Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.
⁴ Cardiovascular Division of Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA.
⁵ Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
⁶ Noninvasive Cardiovascular Imaging Program, Cardiovascular Division of Department of Medicine and Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts, USA; Cardiovascular Division of Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA. Electronic address: rykwong@bwh.harvard.edu.

PMID: 35512951
DOI: 10.1016/j.jcmg.2021.12.003

Abstract

Objectives: The authors investigated the incremental prognostic value of entropy, a novel measure of myocardial tissue heterogeneity by cardiac magnetic resonance (CMR) imaging in patients presenting with ventricular arrhythmias (VAs).

Background: CMR can characterize myocardial areas serving as arrhythmogenic substrate.

Methods: Consecutive patients undergoing CMR imaging for VAs were followed for major adverse cardiac events (MACEs) defined by all-cause death, incident VAs requiring therapy, or heart failure hospitalization. Entropy was derived from the probability distribution of pixel signal intensities of the left ventricular (LV) myocardium.

Results: A total of 583 patients (age 54 ± 15 years, female 39%, left ventricular ejection fraction [LVEF] 54 ± 13%) were followed for a median of 4.4 years and experienced 141 MACEs. Entropy showed strong unadjusted association with MACE (HR: 1.88; 95% CI: 1.63-2.17; P < 0.001). In a multivariable model including LVEF, QRS duration, late gadolinium enhancement, and presenting arrhythmia, entropy maintained independent association with MACE (HR: 1.61; 95% CI: 1.32-1.96; P < 0.001). Entropy was further significantly associated with MACE in patients without myocardial scar (HR: 2.43; 95% CI: 1.55-3.82; P < 0.001) and in those presenting with nonsustained VAs (HR: 2.16; 95% CI: 1.43-3.25; P < 0.001). Addition of LV entropy to the baseline multivariable model significantly improved model performance (C-statistic improvement: 0.725 to 0.754; P = 0.003) and risk reclassification.

Conclusions: In patients with VAs, CMR-assessed LV entropy was independently associated with MACE and provided incremental prognostic value, on top of LVEF and late gadolinium enhancement. LV entropy assessment may help risk stratification in patients with absence of myocardial scar or with nonsustained VAs.

Keywords: cardiovascular magnetic resonance; entropy; myocardial tissue heterogeneity; prognosis; ventricular arrhythmia.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Aged
Arrhythmias, Cardiac
Cicatrix / complications
Contrast Media
Entropy
Female
Gadolinium*
Humans
Magnetic Resonance Imaging, Cine
Middle Aged
Myocardium
Predictive Value of Tests
Prognosis
Stroke Volume
Ventricular Function, Left*

Substances

Contrast Media
Gadolinium