Participants are screened against non-invasive eligibility criteria and scheduled for a hemodynamic evaluation. Following right heart catheterization at rest and during supine bicycle exercise, patients will undergo a brief intracardiac echocardiography (ICE) or transesophageal echocardiography (TEE) exam for septal suitability.~Eligible patients continue with, fluoroscopically and echo guided transseptal puncture and IASD System II implant procedure. If a previously unknown protocol exclusion is discovered during the index procedure, and device is not implanted, participant is followed for 30 days, and then exits the study.~Participants return for follow-up exams 30 days after the implant procedure and annually for 5 years after the implant procedure. In-person visits will take place for the first 2 years. Telephone follow-up and medical chart review will be conducted for years 3-5.
Multicenter, Prospective, Open Label, Single Arm, Clinical Trial.~The primary objective of this clinical trial is to further evaluate the safety and clinical efficacy of the IASD System II in symptomatic heart failure patients with an left ventricular ejection fraction (LVEF) ≥ 40%, and elevated left sided filling pressures despite standard Guideline Directed Medical Therapy (GDMT); and to compare the safety and efficacy results to those from the treatment arm of the REDUCE LAP-HF Randomized Trial II (Corvia protocol 1601).