If you’ve recently received a PAH diagnosis, you may be wondering about your prognosis. Fortunately, treatments for PAH have vastly improved in recent years, extending the life expectancy of those with the condition by several years. If you have PAH, your prognosis depends on several factors, including the type of PAH you’re diagnosed with, your overall health, your race or ethnic background, and the type of treatment you receive.
PAH is a rare disease that’s often difficult to diagnose. This is because many people don’t show early signs of PAH, and it’s typically not seen during a routine physical exam. PAH is caused by narrowing of the blood vessels in your lungs, which increases blood pressure and pulmonary vascular resistance. This puts strain on the right side of the heart as it continues to pump blood. Over time, increased blood pressure in the lungs can cause damage, more noticeable symptoms, and in some cases, right-sided heart failure.
Pulmonary hypertension (PH) and PAH are broken down into four different classes defined by the World Health Organization (WHO). These classes are divided into groups depending on how much your physical and daily activities are limited by PAH. Class 1 is the mildest form and class 4 is the most severe. The classes are as follows:
There are four types of PAH that are diagnosed based on the origin of the cause. Each is associated with different outcomes, but they can be treated to improve life expectancy.
Idiopathic pulmonary arterial hypertension (IPAH) is diagnosed when there’s no known cause for the disease. Your doctor won’t be able to connect it to other common causes. People with IPAH tend to have a poor prognosis when left untreated. The average survival rate in untreated individuals is two to three years after it’s first diagnosed.
Functional class is another measure used to predict life expectancy — those with class 4 PAH are in the high-risk category and tend to have an average survival of less than six months if left untreated. Another predictor is how well the right ventricle (lower right chamber of your heart) is working.
Recent advancements in treatment have extended the life expectancy of many people with PAH to seven years or more. Getting diagnosed and treated early can help you live longer with a better quality of life.
Familial PAH (FPAH), or heritable PAH, is passed down from parents to their children. This form tends to run in families that carry the BMPR2 gene. To develop FPAH, you only need one copy of this gene from either parent — however, only around 20 percent of people who have the gene develop PAH. Although women are twice as likely to develop FPAH than men, men tend to have worse outcomes.
Drug-induced PAH is caused by certain medications that cause damage to your lung’s blood vessels. Many of these medications are used as appetite suppressants or amphetamines. Illicit substance use can also cause drug-induced PAH. Studies show that the outlook for drug-induced PAH is similar to that for IPAH.
There are several other health conditions associated with developing PAH. For example, people with connective tissue diseases such as scleroderma, lupus, or mixed connective tissue disease are at an increased risk of developing PAH. A study found that those age 70 and under with scleroderma-associated PAH (also called systemic sclerosis) have a three-year survival rate of nearly 82 percent.
Other conditions that may cause PAH include:
Some studies have looked into how race, ethnicity, and socioeconomic status (SES) play a role in the prognosis of PAH. These have found that African American and Asian populations have a poorer outlook when other health problems aren’t included.
African Americans tend to have associative PAH more often, especially with connective tissue diseases and liver problems. Other studies from the Journal of the National Medical Association show that African American women specifically have a poorer prognosis when compared to other gender or racial groups.
Doctors and researchers are looking to address diagnosis and treatment gaps in these groups to improve disease outcomes and prognosis.
Life expectancy with PAH may also depend on other risk factors, medical conditions, and complications. As time passes, PAH can cause other conditions to develop that complicate PAH treatment and affect outcomes. Accordingly, these conditions are called complications. Right heart failure is a common complication of PAH that can happen when buildup of pulmonary arterial pressure makes the right ventricle of the heart work harder to move blood to the lungs.
Blood from the body returns to the right side of the heart. When right heart failure occurs, fluid can build up in the venous system and overwhelm the heart’s ability to pump enough blood.
Over the years, PAH treatments have improved significantly. As a result, the life expectancy of those with the disease has also improved. Many treatments are given as combination therapy to help relax blood vessels, treat high blood pressure, and even reverse damage from PAH.
Calcium channel blockers help lower blood pressure by blocking calcium from entering the cells in the arteries and heart. This prevents them from contracting, allowing them to relax and let more blood flow through. Although these are useful medications, only around 5 percent of people with PAH respond well to them in the long term. There aren’t many studies available that show if calcium channel blockers improve survival.
Prostaglandins are a class of medications that mimic the effects of the hormone prostacyclin (prostanoids) in the body, which helps relax blood vessels. Known as vasodilators, these medications help reduce blood pressure and may be effective in some people for treating PAH. Like calcium channel blockers, only a certain group of people respond well to them.
Observational studies suggest that these medications may improve survival rates and disease outcomes in people with severe PAH. Examples of medications that work on the prostacyclin pathway include:
Endothelin receptor antagonists work by limiting the amount of endothelin in the blood, which prevents your blood vessels from constricting (narrowing). Research shows that these medications may slow PAH progression and even reverse damage. Per a study in the European Respiratory Journal, these medications have been shown to improve one- and two-year survival rates to 87 percent to 90 percent in people with idiopathic PAH.
The U.S. Food and Drug Administration (FDA) has approved three endothelin receptor antagonists for treating PAH:
Phosphodiesterase-5 (PDE-5) inhibitors work by blocking the PDE-5 enzyme, to help regulate blood flow and dilate (widen) the arteries in the lungs. These medications have been shown to improve survival rates and disease outcomes in those with PAH.
The FDA has approved two PDE-5 inhibitors for PAH, including sildenafil (Revatio) and tadalafil (Adcirca).
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