Individual data points of PA stiffness measurements before and after 6-months of therapy with bosentan in PAH subjects (n = 14).

Bosentan therapy was associated with no significant changes in PA stiffness indices: compliance (1.51±0.15×10^–2 mm^2/mmHg at baseline vs 1.56±0.15×10^–2 mm^2/mmHg at 6 months, p = 0.86), distensibility (0.31±0.04%/mmHg at baseline vs 0.30±0.03%/mmHg at 6 months, p = 0.92), elastic modulus (763±80 mmHg at baseline vs 756±81 mmHg at 6 months, p = 0.94), and stiffness index β (15.7±1.7 at baseline vs 18.1±1.3 at 6 months, p = 0.198). Data expressed as mean±SEM.