Experts seek origin of pulmonary hypertension to design treatment
After she was diagnosed with pulmonary hypertension during a 2008 pregnancy, Julia Feitner feared she would have to make a choice between her baby's life and her own.
The disease, which impedes passage of blood from the heart to the lungs, is especially hard on pregnant women, whose hearts need to pump extra blood to nourish their babies. Feitner, now 36, learned she had the disease after telling her obstetrician that walking up a flight of stairs exhausted her.
Her due date was six weeks away. Central Pennsylvania doctors told her that medicine that might save her might end her pregnancy, she said. Her mother, a Pittsburgh-area nurse, recommended Feitner contact pulmonary hypertension specialists at UPMC. Feitner was on life support at Magee-Womens Hospital 14 hours later, and eight hours after that she gave birth to a boy in an emergency cesarean section. She spent the next two and a half weeks in intensive care units before returning home.
Pulmonary hypertension also can be fatal in people who are not pregnant. Current medications only slow its progress. Feitner takes four medications and has a subcutaneous IV in her at all times. She hopes new research at UPMC will yield better treatments.
“I will get worse, it's just a matter of when, and suffocating is really not the way you want to die,” she said.
Dr. Stephen Chan, director of UPMC's Center for Pulmonary Vascular Biology and Medicine, is leading a team using new strategies to target the origins of the disease in search for a cure.
“We're really trying to address the burning question: Is there a pathway we can target to do a much better job preventing or curing this disease?” he said.
Feitner has a rare form of the disease, known as pulmonary arterial hypertension, which is estimated to affect 10 to 52 people per million. Doctors are learning that forms of the disease may be more common than once thought, likely affecting tens of millions of people around the world, including many with chronic obstructive pulmonary disease, cardiac disease and HIV. Like Feitner, many patients don't know they have the disease for years before symptoms become obvious.
Pulmonary hypertension killed 17 percent to 56 percent of pregnant women in a group of medical studies over the last three decades, depending on disease type, the years in which they were pregnant and other factors, according to a review of the studies.
Like high blood pressure elsewhere in the body, pulmonary hypertension stiffens arteries in the lungs, making it difficult for the heart to pump blood through them, Chan said. Metabolism in the arteries changes, causing arterial cells to proliferate and clog the vessels, further impeding blood flow. When the strain on the heart becomes too great, it can stop pumping, killing the patient.
In end-stage pulmonary hypertension, many of the muscles in and around the lung arteries contract, a phenomenon that researchers suspect could be related to the changes in metabolism that help the disease progress, Chan said. Most medications seem to relax those contracted muscles, making breathing easier but not stopping the disease, he said.
Researchers in Chan's lab are learning that the arterial stiffness, once thought to be an end result of pulmonary hypertension, is actually one of the first things that happens to those who have the disease.
In a paper published Monday in the Journal of Clinical Investigation, he outlines how two compounds, known as verteporfin and CH-839, show promise in impeding the chain of events that leads from initial stiffness in the arteries to changes in metabolism to heart failure. Doctors have used the compounds to treat cancer and macular degeneration, an eye disease.
“People before us knew what these molecules do; they didn't know they could be utilized to help with a disease they had not been familiar with,” Chan said.
The connection to cancer is important because, as he said, “the uncontrolled growth of a tumor is very similar to the uncontrolled growth of a diseased blood vessel in hypertension.”
Cancer has been studied longer and more thoroughly than pulmonary hypertension, he said, creating opportunities to test already-developed drugs on the rarer disease.
“Pulmonary hypertension is the hallmark worst possible heart abnormality that a person can have,” said Dr. Daniel Edelstone, chief of OB-GYN at UPMC Mercy.
Edelstone delivered Feitner's baby, with help from a large medical team. He said it was one of the most difficult procedures of his 45-year career. He delivered medicine through a respirator to relax the arteries in her lungs and began monitoring blood pressure in different parts of her body. She was so sick that Edelstone decided not to transfer her to an operating room, instead sterilizing the intensive care unit and performing the procedure in the smaller space.
He had to keep the pressure low enough to keep her alive while making sure that it was high enough to continue circulating oxygenated blood to the baby, keeping him alive. The team let her bleed more than during a normal birth to keep blood from filling her lungs.
Afterward, doctors had to carefully administer medications to slowly return her body to normal: many pregnancy-related deaths from pulmonary hypertension occur after the birth.
The risks of pregnancy are so high for women with pulmonary hypertension that very few attempt it, Edelstone said, but some women don't learn they have the disease until they become pregnant.
“There's no question that modern intensive care, critical care approaches to this problem greatly improve the outcome, but it's still an extraordinarily dangerous problem,” he said.
Feitner didn't learn she had the disease until her second pregnancy. She said she wants to see her two sons, now 8 and 11, graduate from high school and be married. She moved to Economy, near Cranberry, in 2009 to be closer to UPMC doctors. She said she has visited intensive-care units more than 20 times for treatment.
One medication she takes is Gleevec, a drug designed to treat leukemia. She takes the drug off-label, and credits it with keeping her alive.
Feitner raises money, including organizing a 5K run each spring, and advocates in Washington, D.C., for pulmonary hypertension research. She said she is excited that UPMC researchers are testing new uses of drugs that have already been developed, because they could more quickly lead to new treatments.
Chan seems optimistic.
“We hope we can do this without the delay of decades that it typically takes for new molecular inhibitors to be developed,” he said.
Wes Venteicher is a Tribune-Review staff writer. Reach him at 412-380-5676 or firstname.lastname@example.org.