Table 2.
Mean values of each ergospirometric parameter for the three tertiles of hemodynamic variables
| mPAP tertiles | ||||
|---|---|---|---|---|
| I | II | III | p | |
| ≤38 mmHg | >38 and ≤52 mmHg | >52 mmHg | ||
| VE/VCO2 slope | 41.0 ± 12.0 | 47.4 ± 15.0 | 48.5 ± 15.3* | 0.02 |
| Peak PETCO2 (mmHg) | 28.1 ± 6.1 | 24.8 ± 5.7** | 24.6 ± 6.0* | 0.006 |
| Peak VO2 (ml/min/kg) | 16.3 ± 5.1 | 15.7 ± 5.2 | 14.3 ± 3.5* | 0.007 |
| Peak O2 pulse (ml) | 9.7 ± 3.6 | 9.1 ± 3.6 | 7.4 ± 2.3*, *** | 0.003 |
| VO2/work slope (ml/min/W) | 10.1 ± 2.2 | 9.7 ± 2.1 | 9.6 ± 2.6 | NS |
| PVR tertiles | ||||
|---|---|---|---|---|
| I | II | III | p | |
| ≤5.9 WU | >5.9 and ≤10.1 WU | >10.1 WU | ||
| VE/VCO2 slope | 41.6 ± 13.3 | 46.1 ± 13.3 | 49.9 ± 15.7* | 0.022 |
| Peak PETCO2 (mmHg) | 28.0 ± 6.0 | 24.8 ± 5.7** | 24.3 ± 5.7* | 0.004 |
| Peak VO2 (ml/min/kg) | 16.9 ± 5.2 | 15.7 ± 4.4 | 13.8 ± 4.1* | 0.007 |
| Peak O2 pulse (ml) | 10.0 ± 3.6 | 9.3 ± 3.4 | 7.1 ± 2.2*, *** | 0.000 |
| VO2/work slope (ml/min/W) | 10.3 ± 2.2 | 9.7 ± 2.2 | 9.4 ± 2.5 | NS |
| CI tertiles | ||||
|---|---|---|---|---|
| I | II | III | p | |
| >2.8 L/min/m2 | >2.2 and ≤2.8 L/min/m2 | ≤2.2 L/min/m2 | ||
| VE/VCO2 slope | 45.2 ± 12.8 | 43.7 ± 14.6 | 48.2 ± 15.2 | NS |
| Peak PETCO2 (mmHg) | 26.2 ± 5.7 | 26.6 ± 6.0 | 24.5 ± 6.0 | NS |
| Peak VO2 (ml/min/kg) | 16.0 ± 4.0 | 16.8 ± 4.7 | 14.0 ± 5.0*** | 0.01 |
| Peak O2 pulse (ml) | 8.8 ± 3.1 | 9.0 ± 3.3** | 8.5 ± 3.7* | 0.000 |
| VO2/work slope (ml/min/W) | 9.9 ± 2.4 | 10.2 ± 2.2 | 9.3 ± 2.3 | NS |
| RAP tertiles | ||||
|---|---|---|---|---|
| I | II | III | p | |
| ≤6 mmHg | >6 and ≤8 mmHg | >8 mmHg | ||
| VE/VCO2 slope | 44.3 ± 14.2 | 42.5 ± 11.2 | 48.9 ± 16.3 | NS |
| Peak PETCO2 (mmHg) | 26.1 ± 5.6 | 27.3 ± 5.2 | 25.0 ± 7.1 | NS |
| Peak VO2 (ml/min/kg) | 16.8 ± 5.3 | 16.5 ± 4.2 | 13.5 ± 3.7*, *** | 0.002 |
| Peak O2 pulse (ml) | 9.0 ± 3.5 | 10.2 ± 3.5 | 7.6 ± 2.8*** | 0.024 |
| VO2/work slope (ml/min/W) | 9.8 ± 2.0 | 10.6 ± 2.0 | 9.4 ± 2.9 | NS |
Note: Data are expressed as mean ± SD.
Abbreviations: ANOVA, analysis of variance; CI, cardiac index; mPAP, mean pulmonary arterial pressure; NS, nonsignificant; PAH, pulmonary arterial hypertension; PETCO2, end‐tidal carbon dioxide pressure; pulse O2, oxygen pulse; PVR, pulmonary vascular resistance; RAP, right atrial pressure; VO2, oxygen uptake; VE/VCO2 slope, ventilation to carbon dioxide production slope; VO2/work, oxygen uptake to work slope.
*
p for ANOVA < 0.05 III group versus I group
**
p for ANOVA < 0.05 II group versus I group
***
p for ANOVA < 0.05 III group versus II group.