Wedge pressure may help predict BPA results in CTEPH cases
Elevated pressure did not impact safety or survival, study shows
People with chronic thromboembolic pulmonary hypertension (CTEPH) who have a high pulmonary arterial wedge pressure (PAWP) — a measure of pressure in the heart’s left atrium, which receives blood from the lungs — may see fewer benefits from balloon pulmonary angioplasty (BPA).
These patients had smaller drops in pulmonary arterial pressure after BPA, a procedure used to open narrowed or blocked pulmonary blood vessels, compared with those who had normal PAWP. That’s according to a retrospective study analyzing 170 CTEPH patients treated with BPA.
Even so, elevated PAWP did not affect BPA safety or patients’ overall survival, “suggesting that BPA remains a viable option in this subgroup, albeit with more modest clinical gains,” the researchers wrote.
The study, “Impact of elevated Pulmonary Arterial Wedge Pressure on safety and efficacy of balloon pulmonary angioplasty in the treatment of chronic thromboembolic pulmonary hypertension,” was published in CHEST.
Understanding how CTEPH and heart pressure are connected
CTEPH is a form of pulmonary hypertension (PH), a condition in which blood clots block the pulmonary arteries and cause high pressure in the vessels that carry blood to the lungs.
Prior studies show that having a PAWP higher than 15 mmHg is associated with a poorer prognosis in CTEPH. A higher PAWP often reflects issues on the left side of the heart, which receives blood from the lungs and pumps it out to the rest of the body.
However, it has been unclear how elevated PAWP affects the results of BPA, a minimally invasive procedure that uses a small balloon to widen narrowed vessels.
To address this, researchers in Poland reviewed medical records from 170 people with CTEPH who underwent BPA, comparing those with elevated PAWP (higher than 15 mmHg) and those with normal PAWP (15 mmHg or lower).
Compared with those who had normal PAWP, patients with elevated PAWP were older (70.8 vs. 64.9 years), had a higher body mass index (29.9 vs. 26.2 kg/square meter), and had higher levels of troponin T and creatinine, indicators of heart and kidney stress. They also more commonly had other health conditions such as diabetes, chronic kidney disease, and abnormal heart rhythm.
After BPA, patients with elevated PAWP exhibited a significantly lower reduction in mean pulmonary artery pressure and showed less improvement in pulmonary arterial compliance — how easily the pulmonary blood vessels expand with blood flow.
Levels of NT-proBNP fell in both groups, but the decrease was smaller in patients with elevated PAWP. In addition, unlike patients with normal PAWP, those with elevated PAWP showed no significant improvements in six-minute walk distance, cardiac output, or troponin T levels.
The most common adverse events in both groups were coughing up blood (28.6% to 39.1%) and lung tissue injury that occurred after blood flow was restored (17.4% to 19%).
Medications and long-term outcomes after balloon angioplasty
During follow-up, most people in both groups were prescribed medications for PH, most often sildenafil (sold as Revatio, with generics available) and riociguat (brand name is Adempas, a generic is available).
Over nearly five years of follow-up, 25 people (14.7%) died. While the difference between groups was not statistically significant, people with elevated PAWP had a higher death rate (21.7% vs. 13.6%) and a shorter average survival time (7.9 vs. 10.6 years). A greater reduction in mean pulmonary artery pressure (mPAP) from the start of the study was significantly linked to better survival.
Abnormal heart rhythm and higher body mass index were also significantly associated with a greater likelihood of having elevated PAWP.
According to the researchers, it is “crucial to further investigate parameters that may contribute to suboptimal treatment outcomes to advance and refine treatment strategies, including developing personalized approaches tailored to individual patient profiles and treatment goals.”
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