Riociguat Versus Balloon Pulmonary Angioplasty in Non-operable Chronic thromboEmbolic Pulmonary Hypertension

"Chronic thromboembolic pulmonary hypertension (CTEPH) is a severe form of pulmonary hypertension characterized by obstruction of the pulmonary vasculature by residual organized thrombi, leading to increased pulmonary vascular resistance (PVR), progressive pulmonary hypertension, and right failure. In patients deemed operable, pulmonary endarterectomy (PEA) is the gold standard treatment and is the only potentially curative treatment. However, some patients are ineligible for surgery owing to occlusion of distal vessels. The best treatment option for these non-operable CTEPH patients is not yet established.

Currently, riociguat is the only drug approved in Europe and US for the treatment of non-operable CTEPH. However, medical therapy with riociguat does not address obstructive lesions. In this sense, another treatment option, balloon pulmonary angioplasty (BPA), began recently to gain widespread interest after development in several centers. This procedure uses the standard balloon angioplasty technique to dilate selected pulmonary arteries. The main aim is to reopen vessels occluded by webs and bands. Several teams, mainly from Japan, have reported their experiences with BPA for the treatment of non-operable CTEPH and demonstrated impressive decrease in pulmonary vascular resistance and improvement in functional status and exercise capacity with an acceptable procedure-related risk. Although BPA has never been prospectively evaluated, most of the leading CTEPH centers worldwide have currently added BPA to their therapeutic options. However, no randomized controlled trial comparing safety and efficacy of medical therapy with riociguat versus pulmonary balloon angioplasty has been performed so far. Therefore, the respective places of medical treatment and of BPA in the management of inoperable patients with CTEPH need to be further evaluated. An ancillary study will evaluate the efficacy and safety of employment of two sequentially used treatments at 12 months. The studied population is that of the study RACE. The patient follow-up period will be extended by 6 months, its duration of participation will be in total of 13 months. The exams will be the same as those of the V3 of the RACE study.