Abstract
Rationale: Excessive exercise ventilation in patients with CTEPH is thought to be mainly attributable to increased physiological dead space ventilation due to proximal obstructive thrombotic lesions. Accordingly, pulmonary endarterectomy has been shown to improve ventilatory responses during exercise. The impact of drug therapy on such alterations is still to be determined.
Objective: To evaluate the effect of riociguat on the excessive exercise ventilation in patients with inoperable CTEPH
Methods: 6 patients with inoperable CTEPH performed a symptom-limited ramp-incremental cardiopulmonary exercise testing (CPET) on a cycle ergometer before and 8-12 months after treatment with riociguat.
Results: Long term treatment with riociguat significantly improved six minute walk distance (382 ± 63 to 431 ± 75m, p< 0.05). CPET demonstrated an improvement in ventilatory response to carbon dioxide output during exercise (ΔVE/ΔVCO2) from 65 ± 18 to 46 ± 7 (p< 0.05) and Peak PETCO2 (20 ± 4 to 26 ± 4mmHg, p <0.05), despite a non-significant difference in Peak O2 (861±169mL to 927± 141mL, p>0.05).
Conclusions: Riociguat improves excessive exercise ventilation in patients with inoperable distal CTEPH.
- © 2013 ERS
