Volume 38, Issue 5, May 2025, Pages 431-442Author links open overlay panel, , , , , , , , , , Highlights•

Quantitative cardiac elastography with external vibration maps myocardial stiffness.

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Quantitative cardiac elastography detects wTTR by elevated stiffness.

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Quantitative cardiac elastography is sensitive to wTTR treatment with tafamidis through reduced stiffness.

Objectives

Heart failure is an increasing global health problem. Approximately 50% of patients with heart failure have heart failure with preserved ejection fraction (HFpEF) and concomitant diastolic dysfunction (DD), in part caused by increased myocardial stiffness not detectable by standard echocardiography. While elastography can map tissue stiffness, cardiac applications are currently limited, especially in patients with a higher body mass index. Therefore, we developed cardiac time-harmonic elastography (THE) to detect abnormal diastolic myocardial stiffness associated with DD.

Material and Methods

Cardiac THE was developed using standard medical ultrasound and continuous external vibration for regionally resolved mapping of diastolic shear wave speed as a proxy for myocardial stiffness. The method was prospectively applied to 54 healthy controls (26 women), 10 patients with moderate left ventricular hypertrophy (mLVH; 5 women), and 45 patients with wild-type transthyretin amyloidosis (wTTR; 4 women), 20 of whom were treated with tafamidis. Ten healthy participants were reinvestigated after 2 to 6 months to analyze test-retest reproducibility by intraclass correlation coefficients.

Results

Myocardial shear wave speed was measured with good reproducibility (intraclass correlation coefficient = 0.82) and showed higher values in wTTR (3.0 ± 0.7 m/sec) than in mLVH (2.1 ± 0.6 m/sec) and healthy controls (1.8 ± 0.3 m/sec, all P < .05). Area under the curve values were 0.991 and 0.737 for discriminating wTTR and mLVH from healthy controls, respectively. Shear wave speed was reduced in patients after tafamidis treatment (2.6 ± 0.6 m/sec, P = .04), suggesting the potential value of THE for therapy monitoring. Shear wave speed was quantified in the septum, posterior wall, and an automatically masked region (here stated for the septal region).

Conclusions

Cardiac THE detects abnormal myocardial stiffness in patients with DD with high penetration depth, independent of body mass index and region selection. Based on standard ultrasound components, cardiac THE is cost-effective and has the potential to become a point-of-care method for stiffness-sensitive echocardiography.

Central IllustrationCardiac THE acquisition setup and processing pipeline. A vibration bed was used to continuously excite multifrequency time-harmonic shear waves in the heart, which are encoded by a clinical ultrasound scanner. A time series of the induced vibrational displacement was acquired from which diastolic SWS, as a proxy for diastolic myocardial stiffness, could be retrieved using a wavenumber-based multifrequency inversion algorithm (k-MDEV).Download: Download high-res image (322KB)Download: Download full-size image

Central Illustration. Cardiac THE acquisition setup and processing pipeline. A vibration bed was used to continuously excite multifrequency time-harmonic shear waves in the heart, which are encoded by a clinical ultrasound scanner. A time series of the induced vibrational displacement was acquired from which diastolic SWS, as a proxy for diastolic myocardial stiffness, could be retrieved using a wavenumber-based multifrequency inversion algorithm (k-MDEV).

Keywords

THE ultrasound elastography

Myocardial stiffness

Diastolic dysfunction

HFpEF

Amyloidosis

AbbreviationsARFI

Acoustic radiation force impulses

GLS

Global longitudinal strain

HFpEF

Heart failure with preserved ejection fraction

LAVI

Left atrial volume index

LVH

Left ventricular hypertrophy

mLVH

Moderate left ventricular hypertrophy

MRE

Magnetic resonance elastography

THE

Time-harmonic elastography

wTTR

Wild-type transthyretin amyloidosis

2024 by the American Society of Echocardiography. Published by Elsevier Inc.