| Baseline | Change from baseline | Sildenafil–placebo change differences | p-value | |||
| Sildenafil | Placebo | Sildenafil | Placebo | |||
| Primary outcome | ||||||
| Cycle endurance time s | 268 (205–331) | 221 (182–318) | 149 (26–518) | 169 (0–768) | -7 (-540–244) | 0.768 |
| Secondary outcomes | ||||||
| Maximal exercise tolerance W | 45 (35–59) | 40 (34–46) | 4 (-1–8) | 2 (0–5) | 1 (-2–5) | 0.600 |
| Oxygen consumption at peak exercise mL·min−1 | 862 (654–950) | 743 (649–844) | 92 (30–163) | 22 (-52–64) | 58 (0–128) | 0.074 |
| 6-min walk distance m | 397 (370–437) | 390 (360–426) | 23 (-12–40) | 21 (-12–40) | 0 (-33–29) | 0.935 |
| SGRQ total score | 51.5 (48.1–61.3) | 59.6 (45.0–63.6) | -1.6 (-7.1–8.0) | -0.7 (-6.7–2.0) | 1.3 (-3.5–6.9) | 0.526 |
| SF-36 aggregate physical score | 33.0 (30.5–39.4) | 31.3 (24.2–35.9) | -0.9 (-6.5–3.0) | 0.6 (-7.4–8.5) | -1.7 (-7.2–2.3) | 0.377 |
| SF-36 aggregate mental score | 50.9 (36.4–55.1) | 51.1 (44.3–59.6) | 0.6 (-7.5–3.0) | -3.1 (-13.7–3.5) | 1.6 (-3.7–8.5) | 0.637 |
Data are presented as median (95% CI), unless otherwise stated. n=29 and n=31 for sildenafil and placebo, respectively. Results are based on the imputed data using the 10th percentile to impute, except for St George’s Respiratory Questionnaire (SGRQ), where the 90th percentile was used instead. SF-36: Medical Outcomes Study 36-item Short Form Health Survey.