Pulmonary Hypertension

HomePatientsLung Disease Week at the ATS2014Pulmonary Hypertension ▶ General Information About Pulmonary Hypertension
General Information About Pulmonary Hypertension

Pulmonary Hypertension

What is pulmonary hypertension?

Pulmonary hypertension (PH) is a general term that refers to high blood pressure in the lungs. In regular hypertension (commonly referred to as high blood pressure), the arteries throughout the body are constricted; while in PH, only the vessels in the lungs are affected.  Pulmonary hypertension can occur for a number of reasons and there are many types of PH, one of which is pulmonary arterial hypertension.  

Pulmonary arterial hypertension (PAH) is a chronic and currently incurable disease that causes the walls of the arteries in the lungs to tighten and stiffen. This forces the right side of the heart to work harder to push blood through narrowed arteries in the lung. This extra stress can cause the right side of the heart to enlarge and become less flexible, making it more difficult to push blood out of the heart, through the lungs and into the rest of the body.

There are a few major types of PAH:

  • Idiopathic pulmonary arterial hypertension refers to PAH cases where no cause can be determined
  • Associated pulmonary arterial hypertension refers to PAH that is secondary to another disease such as connective tissue diseases, congenital heart disease, HIV or others
  • Heritable PAH (sometimes called familial PAH) is a type of PAH that is inherited or genetic and can run in families

What are the symptoms of PAH?

The frequent symptoms of pulmonary arterial hypertension are often common and non-specific:

  • Breathlessness
  • Fatigue
  • Dizziness
  • Chest pain
  • Fainting
  • Swelling of the arms, legs or abdomen

Because these symptoms are fairly common, PAH can remain undiagnosed or misdiagnosed for months or even years.

Who is at risk?

People of all ages, races and ethnic backgrounds can get pulmonary arterial hypertension (PAH).  Although anyone can be diagnosed with PAH, there are factors that increase a person’s risk for the disease:

  • A family history of PAH may put someone at higher risk for the disease.  Genetic testing is available to find out if someone carries a gene associated with PAH.
  • Other diseases – like connective tissue diseases, lung disease, liver disease, congenital heart disease and others – can also increase the risk for pulmonary arterial hypertension.
  • Certain types of PAH – such as idiopathic and heritable PAH – are more common in women than men. Pregnancy in women with pulmonary hypertension can be very dangerous and women with PAH who become pregnant have a higher risk of mortality.
  • Living at higher altitudes for many years can increase the risk of PAH.
  • Taking certain drugs, such as methamphetamines and diet drugs such as Fen-Phen (fenfluramine/phentermine) can also increase one’s risk for PAH.

How is PAH Diagnosed?

When your physician first suspects PAH, he or she may schedule a preliminary test, such as an echocardiogram and pulmonary function test. If these tests point to PAH, your doctor will schedule a right heart catheterization – the “gold standard” for PAH diagnosis.  
During this test, a catheter is placed into the veins and advanced into the pulmonary arteries to measure the pressures in both the right side of the heart and the lungs, as well as the amount of blood that the heart pumps (cardiac output). This is the only test that directly measures the pressure inside the pulmonary arteries and should be done in all patients at least once before initiating PAH-specific treatment.

How is PAH Treated?

There are now twelve FDA-approved medications for the treatment of PH. These medications can be administered in several ways, directly into the vein (intravenously), beneath the skin (subcutaneously), orally and by inhalation. PAH medications also work in three distinct ways and can be prescribed alone or in combinations.  

  • Prostacyclins make the blood vessels relax. They mimic a substance called prostaglandin that is often under-produced in PAH patients. These treatments include epoprostenol, treprostinil and iloprost.
  • Endothelin receptor antagonists block endothelin, a substance that tells blood vessels to constrict, which PAH patients tend to have in excess. Treatments in this category include bosentan, ambrisentan, and macitentan.
  • PDE-5 Inhibitors help the lungs to produce more of their own vasodilators which tell blood vessels to relax and, in turn, improve blood flow. This category of treatment includes sildenafil and tadalafil. 
  • Soluble guanylate cyclase agonists impact the binding and action of nitric oxide in cells in the lungs, causing the vessels to relax and widen. Treatments in this category include riociguat.

Four Facts About PAH

  1. Women are up to four times more likely than men to be diagnosed with pulmonary arterial hypertension.

  2. The median time between symptom onset and diagnosis is 14 months. This time has not changed in the past 20 years. 

  3. Nearly 75% of PAH patients are in the later phase of the disease by the time they are diagnosed. By this point they are experiencing significant limitations in ordinary physical activity and treatments are less likely to be effective.

  4. Many patients will see three or more different physicians over a three year period before they are properly diagnosed with PAH.