The purpose of the study is to evaluate the safety and how well the medication sotatercept works versus placebo in treating Heart Failure with a Preserved Ejection Fraction. The study will also look at information obtained from the tests performed as part of the study to see if subjects have improvement in symptoms of heart failure. Participation in this study will last approximately 26 months. During the study period subjects will be asked to attend regular study visits with the research coordinator. These visits will include such activities as blood tests, questionnaires, physical evaluation by a study doctor, a right heart catheterization with exercise, echocardiogram, and 6 minute hall walks. There will be 35 visits as part of participation in this clinical trial.

Participants will be randomized to either the treatment group (and receive the medication) or the control group (and not receive the medication). Subjects will have a 66:33 chance of receiving the study medication during their participation in the trial. The treatment assignment is determined by randomization, where a computer selects at random which treatment group you will be in (like drawing straws). Neither the subject, nor the blinded personnel will know which group subjects are in. Neither the subject nor the study doctor will decide what group subjects are assigned.

REHAB-HFpEF is a multicenter, randomized, attention-controlled, single-blind trial to examine the hypothesis that, a novel, tailored, progressive, multi-domain physical rehabilitation intervention administered to older patients with acute decompensated heart failure (ADHF) with preserved ejection fraction (HFpEF) beginning early during hospitalization and continuing for 12 weeks in a structured outpatient setting, and continuing as a maintenance program will reduce the rate of combined all-cause rehospitalization and death at 6 months (the primary outcome), and reduce major mobility disability (MMD) prevalence at 6 months (the secondary outcome). This trial, REHAB-HFpEF, builds upon preliminary studies, including the phase 2 REHAB-HF trial, which suggests this intervention may yield significant benefits for this population which are largely older, frail, and with few evidence-based treatment options.

The study will recruit a total of 880 consenting patients >=60 years old hospitalized with ADHF with HFpEF. Following informed consent and baseline testing, the participants will be randomized in a 1:1 fashion to receive a novel, progressive, multi-domain rehabilitation and exercise training intervention or attention control. The intervention will include strength, balance, endurance, and mobility training and the specific training exercises will be tailored based on participant performance in each of these domains. The intervention will begin as soon as possible after randomization during the hospitalization and will continue 3 times per week in an outpatient setting for 12 weeks. Those randomized to the attention control will be contacted bi-weekly by study staff to maintain contact, collect information regarding health status, clinical events, and physical activity/exercise, and ensure retention; they do not receive any specific exercise recommendations. Both arms will receive all services ordered by their primary physician (usual care) and undergo measures of physical function, cognitive function, and quality of life (QOL).

Subjects meet inclusion for this study based on obesity (a high body mass index (BMI), which means too much weight for an individual's height), and they have Heart Failure with Preserved Ejection Fraction (HFpEF). This is a condition where the lower left chamber (left ventricle) of the heart is not able to fill properly with blood during the filling phase and the amount of blood pumped out to the body is below normal.
This study will help to find the best dose of HU6 for treating HFpEF, will help to see its impact on weight reduction, and will help to see its effect on subjects' ability to exercise and on how well they feel.
The study is a placebo-controlled double-blind study that will last approximately 28 weeks. There will be 8 clinic visits (approx. 6-8 hours), and 7 phone visits (approx. 20 minutes). The study drug will be capsules taken orally in the morning before eating.
Possible risks are loose bowel movements/diarrhea which was most prominent within the first 2-3 three weeks of dosing and seemed to improve with time and flushing, especially when alcohol is consumed.

The purpose of the study is to evaluate the safety and how well the medication levosimenden works versus placebo in treating Pulmonary Hypertension and Heart Failure with a Preserved Ejection Fraction measured by a 6 minute walk. This is a condition where the lower left chamber (left ventricle) of the heart is not able to fill properly with blood during the filling phase and the amount of blood pumped out to the body is below normal. The study will also look at information obtained from the tests performed as part of the study to see if subjects have improvement in symptoms of heart failure. Levosimendan is a drug that has been FDA-approved for intravenous (IV) delivery to your body. This study aims to determine if the tablet form of the drug is as effective as the IV route. Tablets are much more attainable for patients to manage their heart failure from home, rather than going to an infusion clinic for treatments. Participation in this study will last approximately 12 weeks with the option to continue to the stage 2 phase of the study. If the stage 2 phase is selected as well, participation will last approximately 26 months or a little over 2 years. These visits will include such activities as blood tests, questionnaires, physical evaluation by a study doctor, echocardiogram, and 6 minute hall walks.

Participants will be randomized to either the treatment group (and receive the medication) or the control group (receive an inactive medication). Subjects will have a 50:50 chance of receiving the study medication during their participation in the trial. The treatment assignment is determined by randomization, where a computer selects at random which treatment group you will be in (like drawing straws). Neither the subject, nor the blinded personnel will know which group subjects are in. Neither the subject nor the study doctor will decide what group subjects are assigned.