Medical bridging therapy before pulmonary endarterectomy?

ABSTRACT

Introduction: Pulmonary endarterectomy (PEA) is the recommended treatment for patients with operable chronic thromboembolic pulmonary hypertension (CTEPH). Reducing PVR pre-surgery may lower the surgical risk, but efficacy of drug treatment in operable CTEPH has not yet been proven and surgeons are concerned that dissection may be more difficult in pre-treated patients. Methodology: A randomised, double-blind, placebo controlled, multinational prospective study was performed in patients with operable CTEPH and PVR >800 dynes.sec.cm-5 at baseline (NCT03273257). Patients were randomised to Riociguat or placebo for 3 months prior to PEA. Primary endpoint was the change in PVR from baseline to before PEA. Secondary endpoints included perioperative findings and evaluation of the PEA specimen. Planned recruitment was 88 patients over 2 years. Result(s) The study was terminated early because of slow recruitment and the COVID-19 pandemic. At the time of study cessation, 14 patients were randomised (7 in each group) and 11 patients completed PEA surgery. At diagnosis, PVR was 944.0 dynes.sec.cm-5 in the Riociguat group and 1007.5 dynes.sec.cm-5 in the control group. -5 -5 The mean change in PVR prior to PEA was -28.4% for Riociguat and -6.9% for placebo (p=0.14). Completeness of surgical clearance was as expected in all patients. In the Riociguat group ease of dissection plane was rated as easier in 1, normal in 3 and more difficult in 2. In the control group, it was rated as easier in 1 and normal in 4. There were no surgical complications or post-operative deaths and no new safety signals. Conclusion(s) Due to the premature study discontinuation and the limited sample size, we are unable to determine the impact of bridging therapy on PEA outcomes.