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

Study Purpose

This is an open-label, multicenter study evaluating the dose, effect, safety and tolerability of intravenous PDNO infusion given to patients undergoing cardiopulmonary bypass (CPB) surgery with post-operative acute pulmonary hypertension (aPH).

Recruitment Criteria

Accepts Healthy Volunteers

Healthy volunteers are participants who do not have a disease or condition, or related conditions or symptoms

Study Type

An interventional clinical study is where participants are assigned to receive one or more interventions (or no intervention) so that researchers can evaluate the effects of the interventions on biomedical or health-related outcomes.

An observational clinical study is where participants identified as belonging to study groups are assessed for biomedical or health outcomes.

Searching Both is inclusive of interventional and observational studies.

Eligible Ages 18 Years and Over
Gender All
More Inclusion & Exclusion Criteria

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 (intra aortic balloon pump [IABP] or right/left-ventricular assist device [R/L VAD]) - Echocardiographic evidence of significant tricuspid insufficiency.
  • - Body Mass Index (BMI) >40 kg/m^2.
  • - Estimated glomerular filtration rate (eGFR) < 30 mL/min preoperative value.
  • - Methemoglobin >3% - Indication of liver disease, defined by serum levels of either alanine aminotransferase (ALT), aspartate aminotransferase (AST) or alkaline phosphatase (ALP) above 3 x upper limit of normal (ULN) (preoperative value) - Preoperative haemoglobin <10 g/dL, postoperative: Hb < 9 g/dL.
  • - Thrombocytopenia (platelet count <100,000/mm^3), preoperative value.
  • - Prothrombin time International ratio (INR) > 1.3, preoperative value.
  • - Pregnant or lactating women, or with a positive pregnancy test at screening (for fertile women only) - Ongoing daily treatment the last 3 days with non-steroidal anti-inflammatory drugs (NSAIDs, excluding low dose, i.e. 75 mg, acetylsalicylic acid), new oral anticoagulants (NOACs), warfarin, heparin, clopidogrel (last 5 days).
Low molecular weight heparin (LMWH) is not an exclusion criterion. Any use of PDE5 inhibitors (sildenafil, tadalafil, vardenafil and avanafil) within 48 hours prior to the administration of PDNO.
  • - Known active malignancy within the past 3 years except for localized prostate cancer, cervical carcinoma in situ, breast cancer in situ, or nonmelanoma skin cancer that has been definitively treated.
  • - History of allergy/hypersensitivity to PD or ongoing allergy/hypersensitivity or history of hypersensitivity to drugs with a similar chemical structure or class to PDNO.
  • - History of any other clinically significant disease or disorder.
- Participation in any interventional clinical study or has been treated with any investigational research products within 30 days or 5 half-lives, whichever is longer, prior to the initiation of screening

Trial Details

Trial ID:

This trial id was obtained from ClinicalTrials.gov, a service of the U.S. National Institutes of Health, providing information on publicly and privately supported clinical studies of human participants with locations in all 50 States and in 196 countries.


Phase 1: Studies that emphasize safety and how the drug is metabolized and excreted in humans.

Phase 2: Studies that gather preliminary data on effectiveness (whether the drug works in people who have a certain disease or condition) and additional safety data.

Phase 3: Studies that gather more information about safety and effectiveness by studying different populations and different dosages and by using the drug in combination with other drugs.

Phase 4: Studies occurring after FDA has approved a drug for marketing, efficacy, or optimal use.

Phase 2
Lead Sponsor

The sponsor is the organization or person who oversees the clinical study and is responsible for analyzing the study data.

Attgeno AB
Principal Investigator

The person who is responsible for the scientific and technical direction of the entire clinical study.

Cecilia Kemi, PhD
Principal Investigator Affiliation Attgeno AB
Agency Class

Category of organization(s) involved as sponsor (and collaborator) supporting the trial.

Industry, Other
Overall Status Recruiting
Countries Sweden

The disease, disorder, syndrome, illness, or injury that is being studied.

Pulmonary Hypertension
Arms & Interventions


Experimental: Treatment with PDNO (placebo during baseline and washout observation periods before & after PDNO)

PDNO will be administered as an incremental intravenous infusion of respectively 15 minutes with the planned dosage: 3, 10, 30, 45 and 60 nmol/kg/min. If no effect on MPAP/PVR is seen at 60 nmol/kg/min in the first patients treated, further dose escalation up to 120 nmol/kg/min is possible, if recommended by the Internal Safety Review Committe (iSRC) following careful review of collected safety data. The iSRC will in any case review all collected data after 4, 8 and 12 patients (if applicable also after 16 and 20 patients). PDNO is administered together with a carrier buffer (NaHCO3-) flow into a central venous catheter. Placebo (NaCl, commercially available dilution solution for parenteral use, 9 mg/mL) will be administered during the baseline and washout observation periods before and after start of IMP infusion.


Drug: - PDNO

PDNO consists of propylene glycol (1,2-propanediol, PD) chemically combined with NO (to be donated). The drug substance is formulated as an inherent mixture of 4 structure analogues. The mixture consists of an equilibrium of the 2 regioisomers 1-(nitrosooxy) propan-2-ol and 2-(nitrosooxy) propan-1-ol. In addition, each regioisomer is a racemic mixture.

Drug: - Sodium chloride (placebo)

Placebo (NaCl, commercially available dilution solution for parenteral use, 9 mg/mL)

Contact a Trial Team

If you are interested in learning more about this trial, find the trial site nearest to your location and contact the site coordinator via email or phone. We also strongly recommend that you consult with your healthcare provider about the trials that may interest you and refer to our terms of service below.

International Sites

Gothenburg, Sweden




Sahlgrenska University Hospital, Anaesthesiology and Intensive Care

Gothenburg, , SE-413 45

Site Contact

Sven-Erik Ricksten, MD


+46 (0) 70 788 67 66

Örebro, Sweden




Örebro University Hospital, Vascular and Thoracic Department (Kärl-Thoraxkliniken)

Örebro, , SE-701 85

Site Contact

Jenny Seilitz, MD


+46 (0) 70 788 67 66

For more information, please contact PHA at Research@PHAssociation.org and refer to the terms of service below.

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