Heart failure with Preserved Ejection Fraction (HFpEF) is a distinct clinical heart failure syndrome and represents a critical unmet need in cardiovascular medicine. HFpEF patients have a marked increase in morbidity and mortality and a profound clinical disability. However, to date, no management strategies have been demonstrated to decrease morbidity and mortality or decrease the clinical disability suffered by HFpEF patients. Investigators have postulated that one pivotal reason that previous randomized clinical studies have failed to show efficacy in HFpEF trials centers around the incomplete understanding of the pathophysiologic mechanisms underlying the development of HFpEF. Studies in Veteran patients with HFpEFand in relevant animal models of HFpEF have demonstrated that one critical mechanism contributing to HFpEF are changes in the cardiac interstitium and extracellular matrix (ECM) fibrillar collagen homeostasis. Preliminary studies presented in this application demonstrate that a highly novel application of stem cell therapy to a rodent model of HFpEF results in regression of ECM fibrosis and reversal of LV diastolic dysfunction. These preliminary studies form the foundation for the 3 specific aims proposed in this application that targets HFpEF in Veterans.

The primary and secondary objectives of this study are too determine the safety profile of CAP-1002 administered by intracoronary infusion in patients with Heart Failure and a Preserved Ejection Fraction (HFpEF) and to assess exploratory efficacy endpoints to determine whether treatment of HFpEF patients with intracoronary allogeneic CDCs affects clinical functional status (QOL scores), exercise tolerance (6 Minute Walk Test - 6MWT), exercise hemodynamics (supine exercise ergometry during right heart catheterization), myocardial interstitial fibrosis (MRI with native T1 mapping and calculation of extracellular volume \[ECV\] after gadolinium administration), macroscopic fibrosis by delayed gadolinium enhancement (DGE), and diastolic function (catheterization, echocardiography, BNP).

If a patient fulfills the inclusion criteria of clinical HF, preserved EF, increased BNP, and increased LA size and has none of the exclusion criteria (see details below), they will be consented and undergo CT coronary angiography (to define the coronary anatomy) and donor-specific antibodies (DSA) screen. If significant CAD is identified by CT and confirmed by subsequent coronary arteriography and FFR, subjects will be referred to their physician for consideration of a revascularization procedure. If such subjects undergo a revascularization procedure, subjects may be reconsidered and rescreened for the study, minus a repeat CT, after a minimum of 3 months post-revascularization.

All patients will have CAP-1002 or placebo delivered through a coronary catheter inserted in the right and left coronary arteries using standard techniques in the cardiac catheterization laboratory. A right heart catheter will be used to obtain baseline (pre-infusion) hemodynamics. All patients will receive 25 million cells (CAP-1002) or placebo in each of the 3 coronary arteries. Sequential dose administration of 25 million cells each suspended in10 mL of cryopreservation solution (CryoStor® CS10, BioLife Solutions, Inc.) containing 10% dimethyl sulfoxide (DMSO), and 1800 units heparin and 45 mcg nitro will be delivered via a coronary artery catheter. Additionally, four milliliters of an intermediate wash solution containing saline is also administered to each patient. Patients randomized to the placebo group will receive placebo injections consisting of CAP-1002 minus the active CDC constituent. Each 10ml bag of 25 million cells will be infused over 1 ml/min. All procedures will be performed by the cardiac interventionist (Dr Fernandes). The patient will receive local anesthesia +/- gentle conscious sedation if undue anxiety. During and in between infusions, multiple measures of gas exchange, hemodynamics, including blood pressure and heart rate and monitoring for any arrhythmias (ventricular and supra-ventricular). Fluids are permitted for hypotension during the procedure, as are low dose inotropes such as dobutamine and use of inhaled nitric oxide. VPCs or NSVT can be seen with insertion of the PA catheter as it traverses the RV and is easily remedied by catheter withdrawal. Oxygen will be used in those patients already on O2 therapy at baseline and if needed to treat temporary hypoxia should this occur. If significant adverse events occur, the cell infusion will be terminated. Pre-specified infusion related events include the following within 6 hours of CDC infusion: refractory hypotension requiring pressors and inotropes, significant hypoxemia requiring FiO2 \> 0.4 or an increment of \> 0.2 from baseline, new cardiac arrhythmia requiring cardioversion, ventricular tachycardia, ventricular fibrillation, asystole or pulseless electrical activity, acute severe transfusion reaction (immune or infection related).