Balloon Pulmonary Angioplasty Is a Viable Treatment for Non-Operable CTEPH

Patients with chronic thromboembolic pulmonary hypertension (CTEPH) who underwent balloon pulmonary angioplasty (BPA) saw improvement in invasive and noninvasive metrics without a significant increase in morbidity, according to study findings published in Respiratory Medicine.

As many as 40% of patients with CTEPH may be considered inoperable. Investigators sought to detail a recently instituted single-center BPA program in the US for patients with CTEPH who are unwilling or unable to undergo pulmonary thromboendarterectomy (PTE).

The researchers conducted a retrospective, single-center observational cohort study from August 2018 to August 2021 at the Pulmonary Vascular Disease Clinic at the University of Washington Medical Center (UWMC) in Seattle. The study included 30 patients with CTEPH who, after evaluation, were deemed not to be candidates for PTE. Most of these patients (n=25) had segmental disease, 1 with subsegmental disease on the right side. There were 23 patients with segmental disease and 7 patients with subsegmental disease on the left side.

Patients (average [SD] age, 64.4 [14.8] years; 10 women; 26 White) were on anticoagulation therapy (22 with direct oral anticoagulant). Average body mass index was 29.2 [6.5] kg/m² at their first BPA, and 23 patients had been previously diagnosed with pulmonary embolism, with 23 patients treated with riociguat. There were 5 patients who had undergone prior PTE and experienced recurrent or residual disease.

In all, 135 BPA procedures were performed on 417 segments in a cardiac catheterization laboratory with moderate sedation. Heparin boluses were given during the procedure to all but 2 patients (goal activated clotting time ≥200 seconds). There were 23 patients who underwent more than 2 sessions. Patients completed 4.5 sessions on average (range, 2 to 8). Usually, either balloon tamponade or heparin reversal was used to treat the 20 procedural adverse events and 24 episodes of hemoptysis that occurred. Additionally, 10 wire or microcatheter pulmonary artery perforations occurred, as did 6 pulmonary artery balloon rupture events, most not requiring treatment. Post-procedure intubation was required with 4 events.

Among 26 patients who completed the series, investigators noted improvements in pulmonary compliance (-1.0mL/mmHg; 95% CI, -1.5 to -0.5; P =.0002), pulmonary vascular resistance (-1.9 Wood units; 95% CI, -2.9 to -1.0; P =.0002), and mean pulmonary artery pressure (-6mmHg; 95% CI, -9 to -4mmHg; P =.0001). There were 2 deaths during the study period, 1 peri-procedurally. The researchers noted improvement in walk distance and New York Heart Association functional classification (P =.01). There was no significant improvement in B-type natriuretic peptide and no significant change in creatinine or blood urea nitrogen.

Based on follow-up electrocardiograms available for 18 patients, the investigators noted significant improvement in right ventricular (RV) size and function (46.7% pre-procedure moderate-to-severe dilation vs 1% post-procedure; P =.01) and RV systolic function (36.7% pre-procedure moderately-to-severely reduced function vs 0.0% post-procedure; P =.05), as well as a non-statistically significant improvement in mean RV basal diameter (4.8 cm pre-procedure vs 4.0cm post-procedure; P =.06).

Study limitations include the lack of patient diversity and underpowered sample size.

“Overall, BPA is an acceptable less invasive approach to treating inoperable or high-risk CTEPH patients,” concluded the study authors. “This single-center US experience outlines the initial BPA experience at an established CTEPH center. Our results are similar to other larger cohorts published outside the US but may serve to illustrate the approach and expectations of BPA as this intervention rapidly becomes more widely adopted in North America,” the researchers noted.