Reducing Lung CongestIon Symptoms in Advanced Heart Failure

Main Inclusion Criteria: * Both heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF) patients * NYHA Class II, Class III, or ambulatory Class IV HF * Receiving guideline directed medical and device therapy (GDMT) for heart failure * For NYHA Class III and ambulatory Class IV, at least one prior hospitalization for heart failure within the last year or elevated BNP level of at least 300 pg/ml or NT-proBNP level of at least 1,500 pg/ml. BNP/NT-ProBNP levels corrected for BMI * For NYHA Class II, must have both hospitalization and elevated BNP levels as above specifications Main Exclusion Criteria: * Systolic blood pressure \<90 or \>160 mmHg * Presence of Intracardiac thrombus * Pulmonary hypertension with PASP of ≥70 mm/Hg or PVR \> 4 WU * Significant RV dysfunction - TAPSE \<12mm or RVFAC ≤25% * Left Ventricular End-Diastolic Diameter (LVEDD) \>8cm * Moderate to severe aortic or mitral stenosis * Stroke or TIA or DVT within the last 6 months * eGFR \<25 ml/min/1.73 m\^2 * Anatomical anomaly on TEE or ICE that precludes implantation of Shunt across fossa ovalis (FO) of the interatrial septum * Inadequate vascular access for implantation of shunt, e.g. femoral venous access for transseptal catheterization and inferior vena cava (IVC) is not patent * Hemodynamic heart rhythm, or respiratory instability at time of Final Exclusion Criteria