However , riociguat 2 mg significantly increased stroke volume ( +9 mL [ 95 % CI , 0.4-17 ] ; P = .04 ) and decreased systolic BP ( -12 mm Hg [ 95 % CI , -22 to -1 ] ; P = .03 ) and right ventricular end-diastolic area ( -5.6 cm2 [ 95 % CI , -11 to -0.3 ] ; P = .04 ) , without significantly changing heart rate , PAWP , transpulmonary pressure gradient , or pulmonary vascular resistance .