US Benchmarking Clinical Study

This is a multicenter, prospective, consecutive cross-sectional study with three parallel arms and non-competitive enrollment. The study is designed to advance the clinical understanding of myocardial and hepatic stiffness by using a novel ultrasound elastography device, the eMyosound LYRA. The prospective design is essential because this elastographic assessment is not yet part of standard care, and the investigational device is being made available specifically for this research. Consecutive recruitment will be used to minimize selection bias by inviting all eligible patients to participate. The cross-sectional design means that no longitudinal follow-up visits are required, making the study feasible for a single-visit assessment.

The primary objective is to determine the shear wave velocity (SWV) in the left ventricle, right ventricle, and liver of three distinct patient populations as specified in the Groups and Interventions section of this form.

The study also aims to establish the device's proportion of patients in whom SWV can be estimated, to characterize the distribution of various myocardial and hepatic SWV measurements, and to compare these distributions between the three study arms. We will also investigate the statistical associations between SWV and a range of clinical, ECG, laboratory, and echocardiographic variables to better understand how these parameters correlate with myocardial stiffness. A key part of our methodology involves a test-retest procedure with two independent observers to establish the within-observer repeatability and between-observer reliability of the SWV measurements.

Study Conduct and Procedures The study will enroll a total of 150 analyzable participants (50 per arm) from three medical centers. The total enrollment may reach up to 180 to account for potential dropouts or non-contributing data. The study is confined to a single visit for each participant, with a total estimated duration of 2.5 hours.

At the single visit, after informed consent is signed, patients will undergo a series of assessments. A standard medical history and physical examination will be performed. Patients will also receive a 12-lead ECG, blood work (including NT-proBNP and hsTnT), and a standard echocardiogram with a wide range of measurements.

Following these standard cardiology assessments, the investigational elastographic assessment will be performed with the eMyosound LYRA device, a Class II medical device for real-time sonographic imaging, shear wave measurement, and electrocardiographic recording. The assessment includes two types of shear wave measurements using the device's M3-5 LYRA probe:

Myocardial Shear Wave Velocity (SWV): Measurements will be taken in specific myocardial regions of interest (ROIs), including the right ventricular anterior free wall (RVAW), left ventricular anteroseptal wall (LVAW), and interventricular septum (IVS). These measurements are acquired in both parasternal long-axis (PLAX) and parasternal short-axis (PSAX) views, and the IVS is also measured in the apical 4-chamber (A4C) view.

Hepatic Shear Wave Velocity (SWV): The operator will measure SWV in two distinct ROIs of the liver's right lobe.

The types of measurements include Acoustic Radiation Force Induced Shear Waves (ARF-SWV), which are performed during diastasis, and Natural Shear Waves (N-SWV), which are produced by cardiac movements. For the test-retest procedure, each of the two observers will attempt to acquire 20 repeated valid measurements for each target ROI.

Risk and Safety Management The study is designed to minimize risks, which are similar to those of other echocardiographic devices. Risk management is handled by respecting the device's indications and contraindications and providing detailed training and technical support to investigators. The potential benefit to participants is a free, thorough cardiological assessment. A Data and Safety Monitoring Board (DSMB) will provide independent oversight, review all adverse events, and make recommendations to the sponsor.

Statistical Analysis The study is primarily descriptive and exploratory. The target sample size is 150 analyzable patients. The final analysis will be performed once all participants have completed the study. Two interim analyses are planned: a qualitative analysis after the first 15 patients to check for safety issues and a quantitative analysis after the first 75 patients to check data quality.

Inclusion criteria

Inclusion criteria

Common to all three Study Arms:

• Male or female age ≥ 60 years
• Signed informed consent and able to comply with protocol

Inclusion criteria

Common to the Heart Failure with non-reduced left ventricular ejection fraction (LVEF) with or without transthyretin amyloid cardiomyopathy (ATTR-CM) Arms:

• Patients meeting the Universal Definition of Heart Failure & HeartShare study criteria.
• LVEF >40% on the last available imaging study
• Left ventricular hypertrophy (LVH) defined as left ventricular mass index (mass/BSA) in female > 95 g/m², in male > 115 g/m² according to American Society of Echocardiography/European Association of Cariology (ASE/EAC) guidelines42 OR as interventricular septum (IVS) thickness ≥12 mm

Inclusion criterion specific to HF with non-reduced LVEF without ATTR-CM Arm:

• Negative (grade 0) Pyrophosphate (PYP) scintigraphy within 24 months prior to the enrolment in the study OR Simple Score <643 OR negative endomyocardial biopsy

Inclusion criterion specific to HF with non-reduced LVEF with ATTR-CM Arm:

• ATTR-CM objectively confirmed and classified at any time prior to the enrollment in the study, with monoclonal protein AL amyloidosis ruled out, according to American Heart Association (AHA) 2020 criteria

Inclusion criteria

in Control Subjects:

• No diagnosis of HF or cardiomyopathy according to the universal definition of Heart Failure
• No diagnosis of Transthyretin amyloid cardiomyopathy (ATTR-CM) or Amyloid light-chain (AL) amyloidosis

Exclusion criteria

Exclusion criteria

common to the three arms:

• Pregnant OR pre-menopausal woman
• Vulnerable patients
• Acute Coronary Syndrome within 30 days
• Heart rate greater than 130 beats/minute at the time of the measurements
• Atrial fibrillation or flutter at the time of SWV measurement (history of AF is authorized provided they patient is in sinus rhythm at the time of the measurements)
• Any clinically significant cardiac arrhythmia at the time of SWV measurement
• Poor echogenicity preventing accurate ultrasound measurements
• Patients with segmental wall motion abnormalities thought to be due to myocardial infarction.
• Severe mitral or aortic valve disease (regurgitation or stenosis) excluded if the cause is other than ATTR (e.g., prolapse, endocarditis, prosthetic valve.)
• Severe tricuspid valve disease (regurgitation or stenosis) excluded if the causes are other than ATTR.
• Distance from skin to IVS ≥ 8 cm
• Any prosthetic mechanical valve
• Patients with mechanical cardiac assist devices other than pacemakers or defibrillators
• Heart, lung, liver or kidney transplant history or expected in the next year
• Severe renal impairment with eGFR < 15 mL/min/1.73m² or end-stage renal disease or patient on dialysis.
• Presence of any competing life-threatening risk over the next 12 months
• Complicated uncontrolled diabetes mellitus HbA1c ≥9% with target organ damage.
• Uncontrolled and persistent high-blood pressure with diastolic pressure > 100 mmHg or systolic pressure > 160 mmHg at the time of the measurement.
• Acute decompensated state such as volume overload, etc. in the opinion of the study investigator
• Skin abnormalities, infections, or open wounds at the site of the SVW measurement
• Liver disease, at least moderate

Exclusion criteria

in both the HF with non-reduced LVEF with or without ATTR-CM Arms:

• Known inherited cardiomyopathy, infiltrative cardiomyopathy (other than ATTR-CM for the study arm for ATTR-CM), cardiomyopathy from muscular dystrophies, cardiomyopathy with reversible causes (e.g., stress cardiomyopathy), hypertrophic cardiomyopathy or known pericardial constriction
• History of treatment for ATTR-CM with Transthyretin (TTR) depleters

Exclusion criteria

Specific to Control Subjects:

• Any diagnosis of cardiomyopathy or HF, whatever the cause46
• LVH based on LV mass index female >95 g/m², in male ≥115 g/m² OR IVS thickness ≥12 mm unless thought to be due to athlete's heart