Riociguat/Balloon Pulmonary Angioplasty Improves Inoperable CTEPH Survival

The combination of riociguat and balloon pulmonary angioplasty (BPA) for the treatment of inoperable chronic thromboembolic pulmonary hypertension (CTEPH) is associated with excellent 5-year survival rates, according to the results of a prospective, observational cohort study published in The Journal of Heart and Lung Transplantation.

The researchers sought to evaluate the effects of the soluble guanylate cyclase stimulator riociguat plus BPA on the prognosis of patients with inoperable CTEPH.

A total of 138 technically inoperable patients who were treated with riociguat plus BPA at a single CTEPH referral center from March 2014 to August 2019 were included in the present analysis. The researchers also compared the long-term survival rates for this patient cohort and a cohort of 237 inoperable patients who had been recruited from 2007 to 2009 in the first international CTEPH registry (ie, the historical cohort).

CTEPH was confirmed in symptomatic participants following 3 months of effective anticoagulation if they presented in at least World Health Organization (WHO) functional class II with a mean pulmonary arterial pressure of at least 25 mm Hg at rest and pulmonary vascular lesions on computed tomography and/or selective biplanar pulmonary artery angiography.

In the more recent cohort, a total of 745 interventions were performed with an average (SD) of 5 (2) sessions and 11 (3) treated pulmonary segments per patient. The median time from CTEPH diagnosis to the first intervention was 208 days (range, 126 to 396 days).  Overall, 112 of the 138 participants from the riociguat-plus-BPA arm underwent reassessment at 6 months after their last intervention; 97.3% of them were still receiving treatment with riociguat.

In comparing survival rates between the recent vs historical cohorts at various timepoints following diagnosis of inoperable CTEPH, the investigators found that 1-year survival was 100.0% vs 84.6%, respectively; 2-year survival was 96.7% vs 76.6%, respectively; 3-year survival was 68.5% vs 92.9%, respectively; and 5-year survival was 90.0% vs 58.5%, respectively.  

Additionally, when 83 well-matched pairs from the 2 patient cohorts were compared, survival was markedly better in the group treated with riociguat plus BPA than in the historical cohort (hazard ratio, 0.145; 95% CI, 0.05-0.421).

Limitations of the current study include: lack of a control group; nonparallel cohorts, with modern cohort data derived from patients from a single center, and historical cohort data derived from an international registry; temporal bias; and uncertainty regarding how many patients from the historical cohort would have been candidates for BPA.

The study authors noted that “In our experience, BPA is an option for the majority of inoperable CTEPH patients: in the last 3 years, 31.5% of all patients evaluated at our center were considered to be inoperable, and 79.7% of these inoperable patients were candidates for BPA.” The researchers concluded that inoperable CTEPH no longer “implies a poor prognosis” because “The multimodal treatment strategy employing both riociguat and BPA is associated with an excellent 5-year survival rate in inoperable CTEPH patients.”

Disclosure: Some of the study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.