This study is enrolling subjects with tricuspid regurgitation, which is what occurs when the tricuspid heart valve on the right side of the heart does not close properly and blood leaks backwards. Over time this can lead to symptoms like shortness of breath and fluid build up in the legs, abdomen, and lungs. This study involves a new investigational device called the TricValve® Transcatheter Bicaval Valve system to treat the leaky valve. Investigational means it is not approved for commercial use by the Food and Drug Administration. (FDA) This study will last about 5 years and include about 11 visits. Study related procedures include physical exams, right heart catheterization (an invasive procedure to check pressures inside the heart), echocardiograms (ultrasound test of the heart), CT scan, blood work, questionnaires, hall walk test and procedure to place the device. Risks include those related to the device and procedure such as infection, failure of the device, worsening of your symptoms or other cardiac complications. There are also risks associated with study testing such as radiation risks, blood draw risks, loss of confidentiality and unknown risks. There is potential benefit to you and to others in the future from what is learned from this study.

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 2:1 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. Participants from the placebo group in CADENCE who enter HARMONIZE at Visit 9a will be randomized 1:1 to one of the active treatment groups. Participants from an active treatment group in CADENCE entering HARMONIZE after Visit 9a will be allocated to continue in the same treatment group (ie, sotatercept dose level) as in CADENCE.