New data show need for improved monitoring for pulmonary hypertension following pulmonary embolism

Results from a retrospective cohort study presented at the American Thoracic Society (ATS) 2015 International Conference in Denver found that the incidence of pulmonary hypertension (PH) among patients who experienced pulmonary embolism (PE) was twice as high as expected based on previous studies, and that many patients do not receive necessary follow-up tests.^1,2,3

"These data indicate that, despite the risk of pulmonary hypertension among pulmonary embolism patients, the use of tests necessary to identify PH - and that determine the specific type of PH - is lacking," said Dario Mirski, M.D., vice president and head, U.S. Medical Affairs, Bayer HealthCare Pharmaceuticals.

The study, which investigated the incidence of PH diagnoses following acute PE in the U.S., concluded that the two-year cumulative incidence of PH is 7.6 percent. The study also evaluated routine disease monitoring practice in PE patients and found nearly half (45 percent) did not undergo imaging tests that could identify PH within 24 months of their PE diagnosis - even though 87 percent of these patients showed signs and symptoms suggestive of the disease.⁴

"The need for improved monitoring of these patients is especially important, as the various types of PH are more prevalent than previously thought," said Richard Channick, M.D., director of Massachusetts General Hospital's Pulmonary Hypertension and Thromboendarterectomy Program.

One such diagnostic test is the lung ventilation/perfusion, or VQ scan, an imaging test that measures air and blood flow in the lungs.⁵ The VQ scan is recommended as the preferred screening diagnostic for a rare, life-threatening form of PH, called chronic thromboembolic pulmonary hypertension (CTEPH).⁶ CTEPH has symptoms similar to those of other more common conditions, such as asthma and chronic obstructive pulmonary disease, as well as other types of PH. However, unlike other types of PH, CTEPH is potentially curable with pulmonary endarterectomy surgery⁷. In part because of the nonspecific symptoms, CTEPH is underdiagnosed and often misdiagnosed as another disease.⁸

"These findings are important because the progression of PH can be slowed with effective treatment," said Victor Tapson, M.D., director of the Venous Thromboembolism and Pulmonary Vascular Disease Research Program at Cedars-Sinai Medical Center in Los Angeles. "Consistent use of accurate PH imaging diagnostics is critical to effective treatment."

About Pulmonary Hypertension

PH is a severe, progressive, life-changing and life-threatening disorder of the heart and lungs in which the blood pressure in the pulmonary arteries is above normal, and which can lead to heart failure and death.^{9, 10, 11}The most common symptoms of PH include shortness of breath, fatigue, dizziness and fainting, all of which are worsened by exertion.^12,13 As the symptoms of PH are non-specific, diagnosis can be delayed by as much as two years.^{14, 15}

About Chronic Thromboembolic Pulmonary Hypertension (CTEPH)

CTEPH is a progressive and life-threatening disease and a type of PH, in which it is believed that thromboembolic occlusion (organized blood clots) of pulmonary vessels gradually lead to an increased blood pressure in the pulmonary arteries, resulting in an overload of the right heart. CTEPH is a rare disease and is comparable in terms of population size to PAH, though there are fewer diagnoses made so far. CTEPH may evolve after prior episodes of acute pulmonary embolism, but the pathogenesis is not yet completely understood. The standard and potentially curative treatment for CTEPH is pulmonary endarterectomy (PEA), a surgical procedure in which the blood vessels of the lungs are cleared of clot and scar material. However, a considerable number of patients with CTEPH (20%-40%) are not operable and in up to 35% of patients, the disease persists or reoccurs after PEA.