Balloon Pulmonary Angioplasty May Safely Treat Inoperable CTEPH

Balloon pulmonary angioplasty (BPA) is a safe and effective, minimally invasive treatment for people with inoperable chronic thromboembolic pulmonary hypertension (CTEPH), according to a study from the U.K.

The study describes the treatment of the first group of CTEPH patients to be treated with BPA.

“Balloon pulmonary angioplasty for inoperable chronic thromboembolic pulmonary hypertension: the UK experience,” was published in the journal openheart.

CTEPH is a rare form of pulmonary hypertension, characterized by high blood pressure in the arteries that supply blood to the lungs. The disease is caused by blood clots that obstruct these pulmonary arteries.

Pulmonary endarterectomy (PEA) is an established treatment to remove blood clots, and the recommended treatment approach for CTEPH patients. But PEA is a major surgical procedure, with an intraoperative mortality rate of around 2.2%, and a major complication rate of nearly 50%.

An estimated 40% of CTEPH patients are also ineligible for the PEA procedure, and 20% of patients undergoing PEA may still be left with only partial lung function. Inoperable CTEPH patients tend to have less favorable prognoses, and higher symptom burden.

BPA involves placing balloon catheters into pulmonary vessels, then inflating them to unblock the vessel and restore healthy blood flow.

Analyses of past BPA use suggest that the procedure is equivalent to PEA, but no randomized, controlled trial data have been published to date.

Researchers with the Royal Papworth Hospital evaluated the efficacy and outcomes of BPA in 30 inoperable CTEPH patients (22 males; mean age of 63.5) treated between October 2015 and April 2018. The national BPA service in the U.K. opened in October 2015.

Patients underwent an average of three BPA treatment cycles at one-month intervals.

Results showed that each BPA course improved all hemodynamic measures, in particular the mean pulmonary arterial pressure (mPAP; mean reduction of 44.7 to 34.4 mm Hg at three months post-procedure) and pulmonary vascular resistance (PVR; mean reduction of 663 to 436 dyn.s.cm^-5). Both mPAP and PVR are measures of how hard the heart must work to pump blood through pulmonary vessels.

A modest improvement in cardiac output (the amount of blood the heart pumps in one minute) was also observed after BPA. Such improvement resulted in better exercise capacity and symptom scores, as measured by the Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR).

Patients also showed clear evidence of reduced right heart strain, and beneficial changes in the size and workings of the right ventricle.

Importantly, researchers found that BPA’s meaningful improvements in clinical measurements translated into symptomatic and quality-of-life benefits for the patients.

No deaths or life-threatening complications were reported, and no one required intensive care or emergency intubation.

Complications that did occur were deemed mild to moderate (10.5% of the cases). These consisted of access site bruising, acute lung injuries, and lung reperfusion edema (fluid retention often seen in lung transplants).

Based on the results, researchers concluded that BPA “is safe and effective in treating inoperable CTEPH with clinically meaningful improvements in haemodynamics, exercise capacity, ventilatory efficiency, and RV [right ventricle] dimensions that translate into symptomatic benefit and improved QoL [quality of life] for patients,” they wrote.

These results also led them to speculate that BPA may be more effective than medications in treating CTEPH patients. However, the researchers noted that a first clinical trial testing BPA versus riociguat (marketed as Adempas, by Bayer) has not  published its results (the RACE trial, NCT02634203). More studies are needed.

“Further work is also required to explore the nuances of the optimal BPA strategy,” the team added.