Intracardiac Flow Assessment in Cardiac Amyloidosis

Inclusion Criteria:

• Subject is clinically stable without cardio-vascular-related hospitalizations within 6 weeks prior to enrollment as assessed by the investigators.

• Subject is able to provide written informed consent and is willing and able tocomplete study procedures.

• Currently in sinus rhythm by clinical assessment or documented electrocardiographicstudies.

• Subject and disease characteristics noted by medical record review:

• Healthy control volunteers must also meet the following criteria: Karnofskyperformance scale > 80%; ECOG status 0 or 1.

• ATTR cardiac amyloidosis based on meeting all the following criteria: Diagnosisof amyloidosis within five years prior to study screening; Documentation ofabsence of AL, heavy chain disease, multiple myeloma or malignantlymphoproliferative disorders; Transthyretin amyloid deposits in cardiac tissueOR technetium (99mTc) pyrophosphate scintigraphy with grade 2 or 3 cardiacuptake OR Transthyretin amyloid deposits in non-cardiac tissue withechocardiographic evidence of cardiac involvement or an end-diastolic mean wallthickness >12mm OR Transthyretin amyloid deposits in non-cardiac tissue withCMR diagnostic of amyloidosis

• AL with cardiac involvement based on meeting all the following criteria:Diagnosis of amyloidosis within five years prior to study screening;Histopathologic diagnosis of amyloidosis with AL protein identification;Documented clinical signs or symptoms consistent with heart failure; Cardiacinvolvement as defined by: Amyloid deposits in cardiac deposits OREchocardiography with an end-diastolic mean wall thickness > 12 mm in theabsence of other causes OR Elevated NT-proBNP (>332 ng/L) in the absence ofrenal failure or atrial fibrillation OR CMR diagnostic of amyloidosis;

• AL without cardiac involvement based on meeting all the following criteria:Diagnosis of amyloidosis within five years prior to study screening;Histopathologic diagnosis of amyloidosis with AL protein identification; Nodocumented clinical signs and symptoms consistent with heart failure from AL;Absence of cardiac involvement as defined by: Echocardiography with anend-diastolic mean wall thickness < 13 mm if the subject does not have othercauses for increased wall thickness AND NT-proBNP <333 ng/L if the subject doesnot have renal failure or atrial fibrillation AND No CMR diagnostic ofamyloidosis if CMR is available prior to screening.

Exclusion Criteria:

• Unable to consent or unable to complete all study procedures.

• Unable to ambulate for 6 minutes (confirmed at study coordinator visit).

• Unable to maintain in supine position for 30 minutes.

• Unable to maintain breath-holding for 10 seconds (confirmed at study coordinatorvisit).

• Contraindications for safe CMR scanning (e.g., uncontrolled claustrophobia, cochlearimplant, implanted neural stimulator).

• Presence of implantable cardiac pacemaker or defibrillator.

• History of complex congenital heart disease, intracardiac shunt (except for patentforamen ovale), prosthetic valves, prosthesis in the main pulmonary artery orascending thoracic aorta.

• Significant artifact from prior MRI studies.

• Pregnant or breast-feeding women.

• Weight equal to or greater than 155 kg.

• Maximum body side-to-side or anterior-posterior diameter equal to or greater than 70cm.

• Documented non-sinus rhythm within 1 week prior to screening.

• For healthy controls, the following exclusion criteria apply, confirmed per chartreview and/or patient report:

• History of cardiomyopathy or structural heart disease;

• History of valvular disease of greater than mild severity;

• History of coronary artery disease or coronary heart disease;

• History of cardiac or thoracic surgery.

• History of symptomatic, persistent atrial tachyarrhythmia, ventriculartachyarrhythmia, or bradyarrhythmia;

• Left ventricular hypertrophy or abnormally increased myocardial thickness byprior echocardiography, cardiac computed tomography, or CMR;

• Acute kidney injury, OR chronic renal disease with glomerular filtration rate < 45 mL/min/1.73m^2 as per medical record review.

• Uncontrolled hypertension of systolic blood pressure > 150 mmHg or diastolicblood pressure > 90 mmHg as per medical record review;

• Taking three or more anti-hypertensive medications;

• Type 1 diabetes, OR uncontrolled type 2 diabetes mellitus of hemoglobin A1cgreater than 8, as per medical record review;

• Taking three or more diabetic medications;

• History of confirmed stroke or transient ischemic attack, as per medical recordreview;

• Current cigarette smoker;

• History of plasma cell dyscrasia or chronic malignant hematologic diagnosis;

• BMI > 35 kg/m^2.