Long-term treatment with Adempas (riociguat) can reduce right heart size and improve the heart’s pumping function in patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH), results from a retrospective study suggest.
The study, “Right ventricular size and function under riociguat in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension (the RIVER study),” was published at the journal Respiratory Research.
Both PAH and CTEPH are characterized by progressive remodeling of blood vessels that leads to an increase in pulmonary arterial pressure, pulmonary vascular resistance, and right ventricular overload, ultimately leading to right heart failure and death.
Clinical studies demonstrated that treatment with Adempas (marketed by Bayer) could improve exercise capacity in PAH and CTEPH patients, determined by their ability to walk longer distances in six minutes (6MWD test). However, there is little information on the potential of Adempas to prevent structural changes to the heart and impaired activity.
To explore the long-term effect of Adempas in these populations, researchers reviewed the clinical records of patients enrolled in PAH and CTEPH clinical trials testing the therapy, including PATENT-1 (NCT00810693) and PATENT-2 (NCT00863681), PATENT Plus (NCT01179334), CHEST-1 (NCT00855465) and CHEST-2 (NCT00910429), and Early Access (NCT01784562).
These studies included 112 patients who had undergone at least one echocardiographic assessment to evaluate their heart structure and cardiac function during the treatment period. In total, 71 patients were included in the analysis (45% with PAH, and 55% with CTEPH).
Heart imaging data showed that after three, six, and 12 months of treatment with Adempas, the patients had a significant reduction in the right atrial and right ventricular areas, compared with before treatment. In addition, long-term Adempas treatment was associated with a significant reduction in right ventricle thickness, faster tricuspid valve responsiveness, and a significant increase in the heart’s pumping capacity.
After 12 months, treated patients showed a significant increase in mean 6MWD over initial values, suggesting greater exercise capacity.
“To the best of our knowledge this is the first multicenter study showing a reduction of right heart size and improvement of right heart function during treatment with [Adempas] in patients with PAH or CTEPH,” the researchers wrote.