question: Compared to Placebo group what was the result of Riociguat group on Improvement in 6 min walk distance at week 16?
context: Cardiac index improved in inoperable patients by a least-squares mean difference of +0.6 L/min/m2 (95% CI 0.4 to 0.7; p<0.0001), while in persistent/recurrent patients the change was +0.2 L/min/m2 (95% CI −0.1 to 0.5; p=0.17)