PEA surgery may be more effective than BPA for CTEPH: Study
It could have more profound impact on pulmonary circulation, heart function
Pulmonary endarterectomy (PEA), a surgery to remove blood clots in individuals with chronic thromboembolic pulmonary hypertension (CTEPH), may be more effective in improving pulmonary circulation and heart function than balloon pulmonary angioplasty (BPA), according to a recent study.
After treatment, a higher proportion of patients in the BPA group remained with residual symptoms. BPA is a minimally invasive procedure that involves inflating a small balloon in a blood vessel to widen it.
“The reason for limited outcomes after BPA in contrast to PEA is not easily identified because of the differences in lesion types, treatment method, and [underlying disease mechanisms] of residual symptoms after BPA or PEA,” the researchers wrote.
The study, “Difference in efficacy between pulmonary endarterectomy and balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension,” was published in BMC Pulmonary Medicine.
Study compares efficacy of surgery, BPA in CTEPH
CTEPH is a type of pulmonary hypertension, a disease marked by high blood pressure in the pulmonary arteries, the blood vessels that supply the lungs. CTEPH is caused by the formation of blood clots that obstruct blood flow.
PEA and BPA are two treatment approaches for CTEPH. While PEA has been the standard strategy, BPA has emerged as an alternative for patients not eligible for surgery. They treat blood vessels in the lungs differently — PEA removes lesions, but BPA does not.
In this study, researchers in Japan compared the efficacy of the two approaches in people with CTEPH. PEA was performed in 55 patients, while 77 inoperable participants underwent BPA between November 2001 and May 2019.
Participants in the BPA group were older (mean of 69.2 vs. 58.4 years) and were more commonly women (79% vs. 60%) than those in the PEA group. They also had less severe abnormalities in blood flow, including lower mean pulmonary arterial pressure (mPAP: 34 mmHg vs. 43 mmHg) and lower pulmonary vascular resistance, or the resistance to blood flow.
They also had higher pulmonary artery compliance, or a higher elasticity of these blood vessels, and higher cardiac index, which indicates a higher volume of blood the heart pumps per minute relative to the body’s size.
Participants in both groups showed improvements, including in mPAP and pulmonary vascular resistance. However, only patients who underwent PEA showed better cardiac index and reduced resistance-compliance (RC) time, which is calculated from the product of pulmonary vascular resistance and pulmonary artery compliance.
PEA surgery significantly associated with reduction in RC time
When analyzing patients with proximal and distal lesions after PEA separately, cardiac index only significantly improved in people with proximal disease, while RC time was lower in both groups of patients. In the BPA group, a significant reduction in RC time was also seen in those with proximal lesions.
Proximal lesions are in larger, more central arteries, while distal lesions affect smaller arteries located deeper in the lungs.
“Because most operable patients have proximal CTEPH, these patients who undergo BPA may not achieve the same cardiac output outcomes as those who undergo surgery,” the researchers wrote. “A thorough discussion of the appropriate invasive therapy among a CTEPH team is critical for optimal treatment.”
Further analysis revealed that only PEA was significantly associated with a reduction in RC time.
“This suggests that improvement of RC time might be highly correlated with treatment method in CTEPH patients,” the researchers wrote.
The study also demonstrated that a higher proportion of participants in the PEA group were symptom-free three months after the procedure than those treated with BPA (50% vs. 21.1%). Also, more patients who underwent BPA remained with residual symptoms.
“The technical approach of removing [intravascular] organized thrombi [blood clots] and thickened intima [an inner layer of blood vessels] by PEA could have a more profound impact on the pulmonary circulation and cardiac function improvements compared with BPA,” the scientists concluded.
Finally, only patients who underwent BPA experienced a significant increase in exercise ability, determined by the distance walked in the six-minute walking test (361 vs. 310 meters). Both groups experienced an improvement in their New York Heart Association functional classification, which categorizes heart failure based on the severity of symptoms and the ability to perform physical activity.
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