Brief Summary

The investigators propose to study the relationship between right ventricle (RV) steatosis and RV function, exercise capacity, and outcomes in humans with pulmonary arterial hypertension (PAH) and to identify potential drivers of lipid accumulation.

Conditions

• Idiopathic Pulmonary Arterial Hypertension
• Heritable Pulmonary Arterial Hypertension
• Pulmonary Arterial Hypertension Associated With Connective Tissue Disease

Intervention / Treatment

• Other: No Intervention

Primary Outcome Measures

• Change in Right Ventricular (RV) Ejection Fraction (Baseline to 36 months)
  Change in RV ejection fraction will be measured by cardiac MRI.
• Change in Right Ventricular (RV) Lipid Content (Baseline to 36 months)
  Change in RV lipid content will be measured by cardiac proton magnetic resonance spectroscopy (MRS). Lipid content is expressed as a percent of the voxel occupied by lipid.
• Identification of metabolic markers (dihyroxybutyrate, acetylputriscene, hydroxystearate and glucuronate) in the peripheral circulation and coronary sinus. (Baseline to 36 months)
  Metabolite markers will be measured by ultrahigh performance liquid chromatography and mass spectrometry.
• Ratio of BMPR2 isoform B/A. (Baseline to 36 months)
  BMPR2 isoforms A and B and wild type gene expression will be measured by real-time polymerase chain reaction (PCR) and validated by measuring protein content using Western blot test.
• Change in skeletal muscle lipid content. (Baseline to 36 months)
  Change in skeletal muscle lipid content will be measured by skeletal muscle proton MRS. Lipid content is expressed as percent triglyceride (%TG)

Countries

United States

Locations and Investigators

• Vanderbilt University Medical Center, Nashville, United States (Recruiting)

Study Officials

• Evan Brittain, MD, MSCI (Principal Investigator) — Vanderbilt University Medical Center