Pulmonary Hypertension

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General Information About Pulmonary Hypertension

Pulmonary Hypertension

What is pulmonary hypertension?

Pulmonary hypertension is the cornerstone of pulmonary vascular disease.  Now understood as a common comorbid condition, pulmonary hypertension complicates a wide variety of diseases including congestive heart failure, autoimmune diseases, sickle cell anemia, chronic obstructive pulmonary disease and venous thromboembolic disease among them.  Pulmonary arterial hypertension (PAH), a subset characterized by high blood pressure in the small arteries of the lung and is a devastating disease with a chronic, progressive course that often leads to right heart failure and death.

What causes pulmonary hypertension?

Pulmonary hypertension is caused by elevation of the blood pressure in the pulmonary circulation.  This results from sustained vasoconstriction and remodeling of the small arteries of the lungs.  Idiopathic pulmonary arterial hypertension, a severe and deadly form of this disease, has no known cause at this time but a complex interplay between multiple biologic mechanisms is thought to result in the changes observed in the lungs.  A hereditary type of pulmonary arterial hypertension has also been discovered in which a majority of cases have mutations in the BMPR2 gene.  The most common cause of secondary pulmonary hypertension is congestive heart failure, yet we know that many other conditions can also lead to this disease.

What are the symptoms of pulmonary hypertension?

The most common symptoms of pulmonary hypertension are fatigue and shortness of breath.  Many patients may also experience chest pain, heart palpitations, fainting, and swelling of the legs.  These symptoms often are most pronounced during exercise, yet as the disease progresses the level of symptoms at rests intensifies.

How is pulmonary hypertension diagnosed?

A high clinical suspicion is necessary and will lead to the proper testing for pulmonary hypertension.  Initially, noninvasive testing such as pulmonary function tests, chest x-rays or CT scans and echocardiograms are often used to identify patients at risk for pulmonary hypertension.  Those patients with a high suspicion for pulmonary hypertension must then undergo right heart catheterization in which direct measurements of the blood pressure in the lungs can be measured.  This test is also necessary to identify patients with highly reactive blood vessels whom may benefit from the use of calcium channel blockers as treatment for this disease.

What are the treatments for pulmonary hypertension?

Over the past 20 years, we have seen a dramatic shift in our understanding of PAH, which has translated into an arsenal of medications that are specifically meant to target the pulmonary circulation.   For patients that have highly reactive blood vessels at right heart catheterization, calcium channel blockers are often prescribed first and symptoms are monitored closely.  Patients that do not respond to vasoreactivity testing or continue to have progression of symptoms while on calcium channel blockers are prescribed one of three different classes of medications.  Endothelin receptor antagonists (bosentan and ambrisentan), phosphodiesterase type 5 inhibitors (sildenafil and tadalafil), or prostacyclin analogs (epoprostenol, treprostinil, and iloprost) have all been approved for use in pulmonary arterial hypertension.  Two new agents have also been approved within the past year; macitentan is a new form of endothelin receptor antagonist and riociguat is a new class of medication approved for use in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension (CTEPH).  These agents represent the medications that are specifically aimed at lowering the blood pressure in the pulmonary circulation, while other medications such as diuretics and anticoagulants are used for symptom relief and complications of pulmonary hypertension.

We continue to strive for the development of these new agents which will continue to advance our knowledge, hopefully leading to a cure for this deadly disease.  Research into newer mechanisms such as calcium channel abnormalities, mitochondrial dysfunction, hormonal imbalances, genetic testing/therapies, as well as the use of stem cells will continue to shape the future for patients with PAH.


Four Facts About Pulmonary Hypertension

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

  2. The mean (average) time between symptom onset and diagnosis is 2.8 years. This time has not changed in the past 20 years. 

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

  4. Most patients are not diagnosed until they are in the late stages of the disease and are experiencing significant limitations of ordinary physical activity.