The purpose of the study is to see if the administration of sildenafil (Viagra) in patients
with portopulmonary hypertension could be a safe and effective treatment.
Portopulmonary hypertension (PTPH) is a special type of pulmonary hypertension. Pulmonary
hypertension is high blood pressure in the pulmonary arteries that carry unoxygenated blood
from the right ventricle of the heart to the lungs. Pulmonary hypertension results from
constriction, or tightening, of the blood vessels that supply blood to the lungs.
Consequently, it becomes difficult for blood to pass through the lungs, making it harder for
the heart to pump blood forward. This stress on the heart leads to enlargement of the heart
and eventually fluid can build up in the liver and tissues, such as in the legs. Affected
patients can sometimes notice increasing shortness of breath and dizziness.
There is a growing body of evidence suggesting a potential therapeutic role for this
sildenafil in patients with primary pulmonary hypertension. Studies are ongoing regarding
this area.
Our hypothesis is that chronic oral sildenafil will successfully reduce pulmonary artery
pressures by at least 25% (reduction in mean pulmonary artery pressure) and could be an
effective treatment for PTPH, especially in candidates for liver transplantation
Primary Hypothesis To measure the effects of a single dose of sildenafil on pulmonary
arterial pressure in patients with PTPH
Secondary Hypothesis To measure the effects of chronic (3 month) treatment with sildenafil on
pulmonary arterial pressure, safety, and tolerability in patients with PTPH