by Phyllis Hanlon, Contributing Writer
WHO Group 4 PH (CTEPH, chronic thromboembolic pulmonary hypertension, a progressive and life-threatening condition, was the subject of a series of articles published in the July 2016 issue of the Annals of the American Thoracic Society. William R. Auger, MD, penned an introduction to the series that examined the articles, which chronicle the discovery, risk factors, understanding, diagnostic methods and treatment of CTEPH from the early 20th century to current day.
Dr. Auger pointed out that CTEPH was first noted during autopsy almost 100 years ago. It wasn’t until the late 1940s that the condition was detectable prior to death, thanks to cardiac catheterization and angiography. Even with these newer diagnostic techniques, clinicians still under-estimated the incidence of CTEPH. There were also misconceptions and misunderstanding about the development of the condition. “It should be clear that having had a blood clot in the lungs is the starting point for the development of CTEPH, though in about 25 to 30 percent of CTEPH patients, a history of having experienced an acute pulmonary embolus is not present,” said Dr. Auger. Clinicians learned more about the development of the disease with the creation of the CTEPH registry, a report that contains a significant amount of data from patients around the world.
Methods used to diagnose CTEPH have also improved over the years, according to Dr. Auger. Initially, clinicians used lung scans and ultrasound to determine whether the patient had any defects, pulmonary hypertension (PH) and/or right heart dysfunction. But these tests were limited in their ability to accurately diagnose, so clinicians began to use cardiac catheterization as a better way to assess heart function and pulmonary artery pressures, he added. And, “catheter-based pulmonary angiography (i.e., a test to see how blood flows through the lung using x-rays and a special dye), the procedure of choice throughout the 1980s and 1990s,” was also limited in its capabilities, said Dr. Auger.
Still in search of effective tools to diagnose CTEPH, scientists out of the University of California San Diego created the pulmonary angioscope, which helped to see lesions in between the vessels that surgeons previously saw as “organized clots,” Dr. Auger noted. Like many tools before it, the pulmonary angioscope was eventually replaced by the more advanced techniques of computed tomography (CT) and magnetic resonance imaging (MRI) of the chest, he said.
Just as diagnostic methods have evolved, so, too, have treatment options. Dr. Auger noted that by 1982 patients with CTEPH still had poor survival rates. Ongoing research facilitated the development of a surgical option that could remove blood clots from the arteries in the lungs (PTE, pulmonary thromboendarterectomy). So in 1961, surgeons performed the first successful PTE; two years later surgeons performed the first bilateral PTE, he reported. In 1970, the first successful PTE took place at UCSD. Additionally, once clinicians had established a clear diagnosis of CTEPH, they were able to evaluate the patient’s risks and/or benefits from surgery, specifically PTE.
Mortality rates for patients with CTEPH have declined over time with the introduction of PTE, but the “true success of this operation comes in the overwhelming potential in most patients of rendering a cure of their PH and right heart failure,” said Dr. Auger. “Most CTEPH patients would have died of their disease if they hadn’t undergone surgery. They have been restored to a normal life/life expectancy, and when you are operating on teenagers, 20, 30, 40+ year olds, that’s pretty cool!”
Dr. Auger added that CTEPH patients who are not good candidates for surgery have other options nowadays. He reported that during the past four years the FDA has approved a PH-targeted drug for CTEPH. “And now balloon pulmonary angioplasty may be available for certain CTEPH patients who are felt to be inoperable or poor surgical candidates,” he said. “These therapies were unavailable just a short time ago, and now these modalities present the opportunity to improve the lives of considerably more CTEPH patients.”
Each PH patient is different. It is essential that you talk to your own doctor about what treatment options are best for you. For more information on finding a doctor or accredited care center, visit https://www.phassociation.org/PHCareCenters/Patients.