A Study to Evaluate the Efficacy, Safety and Tolerability of PDNO Infusion in Patients With Pulmonary Hypertension After Cardiopulmonary Bypass Surgery

Inclusion Criteria: * Ability to understand and willing to sign an informed consent form (ICF) * Male and female patients, age ≥ 18 years * Planned to undergo elective cardiopulmonary bypass (CPB) for coronary artery bypass grafting (CABG), aortic valve repair (AVR) or mitral valve repair (MVR) with or without CABG * Diagnosed with echocardiographic signs of pulmonary artery systolic pressure (PASP) \>50 mmHg , as estimated by doppler defined echocardiography using a modified Bernoulli equation: PASP ≈ 4 (tricuspid regurgitant jet velocity)\^2 + central venous pressure (CVP) Exclusion Criteria: * History of chronic pulmonary hypertension (PH) (WHO group 1, 3, 4 or 5), not group 2 due to left heart disease * Patients with contraindications for pulmonary artery catheter (PAC) * History of severe chronic obstructive pulmonary disease * Left heart failure with ejection fraction (EF) \<35% * Non-ST elevation myocardial infarction (non-STEMI) or ST elevation myocardial infarction (STEMI) within 1 months prior to informed consent * Stroke (cerebrovascular lesion \[CVL\]), transient ischemic attack (TIA), AV block III within 3 months prior to informed consent or QTcF \>450ms at the time of screening * High inotropic requirement (no more than one inotrope treatment and the vasopressor norepinephrine at time of screening/postoperative evaluation) * (Increased) mediastinal bleeding \>100 mL/hour in mediastinal drainage at postoperative evaluation * Mechanical circulatory assistance (…