Complex sentence: The study revealed potentially unfavorable safety signals with sildenafil plus riociguat, and no evidence of a positive benefit/risk ratio, therefore the concomitant use of riociguat with phosphodiesterase-5 inhibitors is contraindicated.
Split into simpler sentences: The study revealed potentially unfavorable safety signals with sildenafil plus riociguat and no evidence of a positive benefit/risk ratio. Therefore the concomitant use of riociguat with phosphodiesterase-5 inhibitors is contraindicated.