Heart failure often causes fluid to accumulate in the body, leading to congestion and swelling. However, some people who have had heart failure for a long time seem to have very little congestion or swelling, even when the heart failure is poorly treated. The investigators think that this is because lymphatic vessels are able to grow and remove fluid to prevent congestion. The investigators do not know how lymphatic vessels grow. This study will investigate the blood levels of various proteins to try to figure out how the lymph vessels of people with long-standing heart failure might grow.

Inclusion Criteria:

• Undergoing clinically indicated right heart catheterization.

Exclusion Criteria:

• Unable to provide consent.
• Use of medications which may alter lymphangiogenesis factor expression within 365 days
• Thalidomide, lenalidomide, pomalidomide
• Bevacizumab
• Any cytotoxic chemotherapy agents
• Pregnant
• Any potentially pregnant patient (based on age and gender) undergoes Beta Human chorionic gonadotropin testing as standard of care prior to any right heart catheterization.
• Active cancer within 365 days
• Diagnosis of familial or secondary lymphedema
• Treatment of active bacterial infection within 7 days
• Active inflammatory rheumatologic disease requiring anti-inflammatory therapy administration within 60 days
• Conditions
• Systemic lupus erythematosus
• Rheumatoid arthritis
• Scleroderma
• Inflammatory myositis
• Vasculitis
• Behcet's disease

All Inpatient and Outpatient individuals undergoing clincially-indicated right heart catheterization.