New Approaches to a Lethal Lung Disease

he condition may not be one the average person has even heard of, but primary pulmonary hypertension can be a diagnosis worse than cancer, lung specialist Sean Gaine makes clear.

To illustrate what the brutal lung disease does to the human body, he compares the vascular network in the lung to a six-lane highway. Scarring and stiffening of the blood vessels close down lanes, one by one, in the flow of blood from the heart through the pulmonary artery to the lungs. Finally, a string of bottlenecks block the bloodflow back into the heart and a fatal crash occurs. The right ventricle has to work so hard to pump against increasing pulmonary pressure that it swells, weakens, then fails.

From the time of diagnosis, most people with pulmonary hypertension will live about two and a half years without treatment. But, for those who make their way to a trained lung specialist at a handful of medical centers, the outlook is improving, thanks to advances in care and a powerful new drug, prostacyclin.

At the Pulmonary Hypertension Center here, Gaine’s first step with new patients is to assess the extent of their blood vessel and heart damage by doing a right heart catheterization. The procedure allows him to measure the person’s heart and lung pressures. Then, with nitric oxide and an intravenous dose of the vasodilator prostacyclin (which relaxes blood vessels and eases blood flow through them) he finds out if the vessels in the patient’s lungs have the ability to dilate.

Those who respond well at this point—about 20 percent—tend also to respond well to calcium channel blockers to lower pressure in their lungs. They’re the lucky ones—they have a 90 percent likelihood of surviving five years.

Most people with primary pulmonary hypertension, however, need to use a portable infusion pump and a chest catheter to provide a constant supply of prostacyclin to keep the disease at bay. The drug was originally designed to keep patients alive until they could receive a lung transplant, but physicians have found that it can improve people to the point where they decide to forego surgery.

“In a sense, we’re withdrawing these people from the jaws of death,” Gaine says. “In general, they’ll never be able to overexert themselves again. But many go from being bed-bound with right heart failure to getting back on their feet and doing some of the things they want to do. They’ve finally got hope for a future.”

—- Gary Logan