Bridging therapy prior to balloon pulmonary angioplasty (BPA) in chronic thromboembolic pulmonary hypertension (CTEPH) is associated with improved haemodynamics, with differences between treatment strategies, researchers report.
The real-world observational study found greater improvement in patients receiving phosphodiesterase-5 inhibitor (PDE5i) and endothelin receptor antagonist (ERA) dual therapy than in those receiving monotherapy with PDE5i or riociguat, without differences in overall complication rates.
In addition, although haemodynamic severity at first BPA was associated with rates of lung injury, there were no differences in periprocedural complication rates between bridging strategies.
“These findings suggest that haemodynamic severity at the time of BPA may be more closely associated with procedural complications than the bridging therapy used,” the investigators noted. “Prospective studies are needed to clarify optimal bridging approaches to BPA.”
Full results of the study, which used data from the national UK CURATE registry, are published in Openheart [link here].
The study analysed 158 patients, with the primary outcome defined as the change in haemodynamic and functional parameters between diagnosis with CTEPH and first BPA after bridging PH medical therapy.
The bridging groups included PDE5i monotherapy (n=42), PDE5i and ERA dual therapy (n=67) and riociguat monotherapy (n=49). There was no significant difference in the time from diagnostic right heart catheterisation (RHC) to first BPA, with median durations of 324, 352 and 362 days for PDE5i monotherapy, PDE5i and ERA dual therapy and riociguat monotherapy groups, respectively.
Patients managed with PDE5i and ERA dual therapy had higher baseline mean pulmonary artery pressure (mPAP, p=0.019), right atrial pressure (RAP, p=0.038) and pulmonary vascular resistance (PVR, p=0.004) and lower cardiac output (CO, p=0.017) and cardiac index (CI, p=0.029) compared with either PDE5i or riociguat monotherapy.
Dual therapy was associated with a greater percentage increase in CI (40% vs 13% vs 16%, p<0.001) and CO (34% vs 8% vs 14%, p<0.001) and a greater percentage decrease in PVR (−39% vs −30% vs −25%, p=0.008) and N-terminal pro-B-type natriuretic peptide (−67% vs −21% vs −32%, p=0.004) compared with PDE5i monotherapy and riociguat monotherapy.
Moreover, these differences remained following adjustment for baseline haemodynamic severity.
All three bridging approaches were associated with decreased mPAP and PVR and increased CO and CI from diagnostic RHC to immediately before the first BPA.
Other procedural complications, including pulmonary artery perforation, dissection, haemoptysis and access site complications, were not associated with haemodynamic severity at first BPA.
The researchers noted that riociguat monotherapy was associated with improvement in haemodynamic data, but not to a significantly greater extent than PDE5i monotherapy.
Patients receiving dual therapy experienced greater improvements in haemodynamic parameters than either monotherapy group, which suggests “an additive effect of ERAs”, they said.
They also acknowledged a number of limitations on the study, including that patients were not randomised against matched comparison groups and the fact that those with poorer baseline haemodynamic data “preferentially received PDE5i and ERA dual therapy, with greater potential for improvement”.