Understanding the science behind chronic thromboembolic pulmonary hypertension (CTEPH) has come a long way since, originally, a diagnosis was made postmortem. Although it is commonly underdiagnosed and undertreated, CTEPH can be cured via pulmonary endarterectomy (PEA), a technique that dates back almost to the first diagnosis of CTEPH.
“At the outset, CTEPH was considered to be a rare autopsy curiosity,” reported Dr. Nick H. Kim and Dr. Eckhard Mayer, two researchers who work in the field of pulmonary hypertension, in reference to the pioneering research conducted at University of California, San Diego. “However, it has become apparent that CTEPH is not only more common than had been appreciated, but is also potentially subject to surgical cure.”
Dr. Kim and Dr. Mayer are also interested in treatments for CTEPH that do not require surgery, as nearly 40% of CTEPH patients are deemed inoperable. They compiled a report of recent developments in the field of CTEPH research and treatments and published “Chronic Thromboembolic Pulmonary Hypertension: The Evolving Treatment Landscape” in the journal European Respiratory Review.
Some of the more common therapeutic approaches to CTEPH use off-label pulmonary arterial hypertension medications such as endothelin receptor antagonists, phosphodiesterase type 5 inhibitors, and prostacyclin analogues. Since there is limited evidence that these therapies actually work in the context of CTEPH, other more directed treatments approaches are being pursued.
Riociguat is the first medication-based therapy that may directly help CTEPH. It is a soluble guanylate cyclase stimulator that restores the function of a pathway defective in CTEPH. It was shown to be effective in patients with CTEPH enrolled in the CHEST-1 trial, a study sponsored by Bayer to evaluate efficacy and safety of the company’s experimental BAY63-2521 therapy in Patients With CTEPH. Safety and efficacy data were supported by long-term follow studies, as well.
For patients who may not benefit from riociguat, another option includes balloon pulmonary angioplasty. This technique uses a balloon inflated in the vessels to open blocked blood flow. While it has shown some efficacy in patients with CTEPH, there is a serious risk of death that accompanies treatment, indicating a need to seriously consider the benefits and risks of undergoing this procedure.
According to Dr. Kim and Dr. Mayer, riociguat and balloon pulmonary angioplasty represent “a major leap in the evolution of CTEPH treatment for the first time since PEA and lung transplantation were introduced.” Scientists are embarking on an exciting new era of research in CTEPH, which may lead to better diagnostic tools and more comprehensive treatments strategies.