Your Scleroderma Questions, Answered is a monthly Q&A column featuring responses from the SRF’s Chief Medical Officer, Dr. Gregory Gordon, who shares guidance grounded in decades of clinical expertise.
In this edition, he answers questions about the development and treatment of pulmonary arterial hypertension (PAH).
Question: Why does scleroderma cause PAH?
Answer: Scleroderma injures the small arteries throughout the body by damaging the lining of these vessels. Over time, the vessel walls thicken and scar, and the passages get narrower. When this damage occurs in the fingers and toes, it causes Raynaud’s Phenomenon, where fingers turn white or blue in the cold. When it occurs in the lungs, it causes pulmonary arterial hypertension (PAH).
As the small arteries in the lungs narrow, the right side of the heart has to pump harder to push blood through them. At first there may be no symptoms. But over time, as PAH progresses, it can cause shortness of breath with activity, tiredness or swelling in the ankles. These are signs that the heart muscle is struggling to pump enough blood through the narrowed arteries. In addition, scleroderma itself can directly harm the heart muscle, which makes it harder for the heart to keep up with the extra workload.
Studies show that between 5% and 12% of people with scleroderma develop PAH. It is more common in people with certain antibodies found on blood tests. Early detection and treatment are important, which is why doctors recommend regular screening, using heart ultrasound (echocardiogram), breathing tests and blood work.
Question: Are there any therapies that can prevent the development of PAH in scleroderma?
Answer: Currently, there are no treatments that prevent pulmonary arterial hypertension (PAH) in people with scleroderma. But it is still important to find and treat it early, which is why regular screening is recommended.
The goal of PAH treatment is to lower the pressure in the small arteries of the lungs. Doing so can ease the strain on the heart, improve breathing and slow disease progression. There are a number of classes of medications that can help with this process, such as endothelin blockers (e.g. bosentan), prostacyclin medications (e.g. iloprost), phosphodiesterase-5 inhibitors (e.gsildenafil and tadalafil), and soluble guanylate cyclase stimulators (e.g. riociguat).
These medications work in different ways, but they share the goal of relaxing and widening the small arteries of the lungs and thus decreasing the amount of work the heart must perform to push blood through them. Doctors often start two medicines at once, because combining them works better than one alone. Other treatments can also help, such as oxygen, diuretics (water pills) for swelling, and supervised exercise programs.