The purpose of the study is to evaluate the safety and how well the V-Wave Interatrial Shunt works. The study will also look at information obtained from the tests performed to see if subjects have improvement in symptoms of heart failure. Participation in this study will last approximately 1 year to up to 7 years depending on randomization group. 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, echocardiogram, and 6 minute hall walks. There will be a minimum of 10 or up to 15 planned research clinic visits. Subjects will have 1 overnight hospital stay for the study related RHC and research procedure. Each participant will receive a phone call between all study visits.

Subjects will have a 50:50 chance of receiving the Shunt during the randomization procedure (like the flip of a coin). Neither the subject, nor the blinded study doctor or blinded study coordinator will know which group subjects are in. Participants will be randomized to either the treatment group (and receive the Shunt) or the control group (and not receive the shunt). Neither the subject nor the study doctor will decide what group subjects are assigned.