Fast Induced Remodeling in Heart Failure With Preserved Ejection Fraction

Inclusion Criteria:

• Diagnosis of Heart Failure, Left Ventricular Ejection Fraction (LVEF) ≥ 55% (thisand other measurements must be made within the last year).

• New York Heart Association (NYHA) Functional Class I-III

• Stable on guideline-directed medical therapy (GDMT) heart failure medications asdetermined by the investigator, for at least 1 month, with the exception of loopdiuretic therapy. GDMT should be in accordance with current American HeartAssociation (AHA)/American College of Cardiology (ACC)/Heart Failure Society ofAmerica (HFSA) Guidelines and include consideration of Sodium/glucosecotransporter-2 inhibitors (SGLT2i) therapy.

• V End Diastolic Volume indexed to body surface area (BSA) ≤ 80 mL/m^2.

• Concentric remodeling or concentric hypertrophy defined as at least one of thefollowing criteria:

• Left ventricular (LV) posterior or lateral wall thickness > 11mm

• Relative wall thickness (RWT) > 0.42

• Male and LV mass indexed to BSA ≥115 g/m2

• Male and LV mass indexed to height ≥ 49.2 g/m2.7

• Female and LV mass indexed to BSA ≥ 95 g/m2

• Female and LV mass indexed to height ≥ 46.7 g/m2.7

Exclusion Criteria:

• Unable or unwilling to undergo contrast MRI.

• Class I indication for permanent pacing, except for symptomatic chronotropicincompetence

• Current permanent or persistent Atrial fibrillation (A-fib)

• Structural heart disease requiring intervention

• Aortic valve replacement procedure less than 12 months prior to enrollment

• Known pericardial constriction, genetic hypertrophic cardiomyopathy, or infiltrativecardiomyopathy

• Severe aortic or mitral valve disease, defined as severe regurgitation or a valvearea < 1cm^2

• Exertional angina

• Severe pulmonary disease including severe Chronic obstructive pulmonary disease (COPD) (i.e., requiring home oxygen, chronic nebulizer therapy, or chronic oralsteroid therapy or hospitalized for pulmonary decompensation within 12 months)

• Estimated glomerular filtration rate (eGFR) < 25 ml/min/1.73m^2 as calculated by theModification in Diet in Renal Disease (MDRD) formula

• Uncontrolled blood pressure, defined as systolic pressure outside the range of 100to 160 mmHg despite anti-hypertensive medication.