for people ages 18 years and up (full criteria)
at San Francisco, California and other locations
study started
completion around
Principal Investigator
by Marc A Simon, MD, MS
Headshot of Marc A Simon
Marc A Simon



The main objective of this study is to determine the clinical efficacy of metformin versus placebo and the therapeutic response with regards to functional capacity and hemodynamics in PH-HFpEF.

Official Title

Phase II Trial of Metformin for Pulmonary Hypertension in Heart Failure With Preserved Ejection Fraction


This is a 12-week blinded cross over trial of metformin in PH-HFpEF to improve exercise hemodynamics, functional capacity, and glucose metabolism. This phase II clinical trial will provide detailed phenotyping, physiological and mechanistic data on PH-HFpEF.


Pulmonary Hypertension, Heart Failure, Hypertension, Metformin, Drug: Metformin


You can join if…

Open to people ages 18 years and up

  1. PH-HFpEF Confirmed diagnosis by RHC within the past 6 months:

Mean Pulmonary Arterial Pressure (mPAP) ≥ 25 mm Hg AND Pulmonary artery wedge pressure (PAWP) ≥ 15 mm Hg AND Transpulmonary Gradient (TPG) ≥ 12 mm Hg

OR Exercise measurements

Mean Pulmonary Arterial Pressure (mPAP) ≥ 30 mm Hg AND Pulmonary artery wedge pressure (PAWP) ≥ 20 mm Hg AND PA calculation (change in mPAP/change in cardiac output) = ≥3 mmHg/L/min

  1. Three or more features of metabolic syndrome defined as:

Body Mass Index (BMI) ≥ 30 kg/m² Systolic blood pressure (BP) ≥ 130 mm Hg and/or diastolic BP ≥ 85 mm Hg Elevated waist circumference > 102 cm in men and > 88 cm in women Fasting triglyceride (TG) level over 150 mg/dl High-density lipoprotein <40 mg/dL in men or < 50 mg/dL in women

You CAN'T join if...

  1. Age less than 18 years;
  2. Uncontrolled systemic hypertension based on repeated measurement of sitting systolic blood pressure >170 mm Hg or sitting diastolic blood pressure >95 mm Hg at Screening;
  3. Systemic sitting blood pressure < 110 mmHg systolic or < 60 mm Hg diastolic at Screening;
  4. Hemoglobin A1C > 10;
  5. Currently taking metformin or history of intolerance to metformin or contraindication to taking metformin;
  6. Known type 1 diabetes
  7. Positive urine pregnancy test or breastfeeding
  8. Ejection Fraction < 50%
  9. Dementia;

    11. End-stage malignancy; 12. Major cardiovascular event or procedure within 6 weeks prior to enrollment; 13. Severe valvular disease; 14. Other severe acute or chronic medical, psychiatric or laboratory abnormality that may increase the risk associated with study participation or investigational product administration or may interfere with the interpretation of study results and, in the judgment of the investigator, would make the subject inappropriate for entry into this study or would prevent completion of the study; 15. Current Smoker; 16. Hemoglobin <9 g/dL; 17. Estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m2; 18. Receipt of an investigational product or device, or participation in a drug research study within a period of 15 days 19. <3 months of stable dose of PDE5i


  • UCSF Medical Center accepting new patients
    San Francisco California 94143 United States
  • University of Pittsburgh Medical Center accepting new patients
    Pittsburgh Pennsylvania 15213 United States

Lead Scientist at UCSF

  • Marc A Simon, MD, MS
    Dr. Simon is director of Pulmonary Vascular Disease and the Pulmonary Hypertension Comprehensive Care Center. He has expertise as a cardiologist specializing in pulmonary hypertension, advanced heart failure, and heart transplantation.


accepting new patients
Start Date
Completion Date
University of California, San Francisco
Phase 2 research study
Study Type
Expecting 10 study participants
Last Updated