Table 2.
CPX Results for a Number of Principal Variables Divided Into Disease Categories; COPD and HFrEF
| COPD (n = 25) |
HFrEF (n = 40) |
Healthy Adults (n = 134) |
|
|---|---|---|---|
| Peak VO2, ml/min∗† | 1,356 ± 73 | 1,299 ± 56 | 1,937 ± 31 |
| Peak VO2, ml/min/kg∗† | 16.7 ± 0.9 | 16.5 ± 0.7 | 24.4 ± 0.4 |
| Peak VO2, % predicted∗† | 69.9 ± 3.4 | 70.6 ± 2.6 | 101.0 ± 1.4 |
| AT, ml/min∗† | 983 ± 60 | 941 ± 39 | 1,157 ± 22 |
| AT, % of predicted peak VO2∗† | 52.4 ± 2.9 | 51.2 ± 1.8 | 60.3 ± 1.0 |
| OUES‡ | 2.11 ± 0.09 | 1.50 ± 0.07 | 2.27 ± 0.04 |
| OUES/kg†§ | 27.0 ± 1.2 | 19.1 ± 0.9 | 28.6 ± 0.5 |
| OUES, % predicted†§ | 105.6 ± 4.1 | 72.6 ± 3.1 | 102.5 ± 1.7 |
| OUEP§ | 30.5 ± 1.0 | 33.5 ± 0.8 | Not recorded |
| O2 pulse, ml/beat‡ | 10.7 ± 0.5 | 12.1 ± 0.4 | 13.8 ± 0.2 |
| O2 pulse, % predicted∗† | 77.9 ± 3.2 | 82.6 ± 2.5 | 100.0 ± 1.3 |
| VE/VCO2 slope 1∗† | 33.6 ± 1.1 | 36.0 ± 0.8 | 26.5 ± 0.5 |
| VE/VCO2 slope 2 | 34.1 ± 1.9 | 38.6 ± 1.5 | Not recorded |
| VE/VCO2 ratio nadir | 35.2 ± 1.2 | 33.9 ± 0.9 | Not recorded |
| VE/VCO2 ratio at AT∗† | 38.7 ± 1.2 | 35.7 ± 0.8 | 29.0 ± 0.4 |
| RER at peak§ | 0.99 ± 0.02 | 1.11 ± 0.02 | Not recorded |
| PETCO2 at AT, mm Hg∗† | 34.8 ± 1.0 | 35.1 ± 0.7 | 38.7 ± 0.4 |
| HR at peak, beats/min‡ | 126 ± 4 | 115 ± 3 | 141 ± 2 |
| DP, mm Hg beats/min§ | 23,566 ± 1205 | 17,630 ± 907 | 28,871 ± 493 |
| Circ power, mm Hg l/min∗† | 259.3 ± 20.7 | 196.6 ± 15.6 | 398.9 ± 8.5 |
| Peak O2 saturations, %§ | 94 ± 1 | 98 ± 1 | Not recorded |
| BR at AT, %§ | 49.8 ± 2.8 | 69.5 ± 1.8 | Not recorded |
| BR, %∗§ | 9.3 ± 3.0 | 42.6 ± 2.3 | 46.8 ± 1.2 |
| VO2/WR slope†§ | 9.8 ± 0.3 | 8.7 ± 0.2 | 9.7 ± 0.1 |
| HR/VO2 slope∗ | 0.043 ± 0.003 | 0.045 ± 0.002 | 0.042 ± 0.001 |
| Peak work rate, W‡ | 85 ± 6 | 93 ± 5 | 145 ± 3 |
| Duration, mins:s | 10:32 ± 0:19 | 11:05 ± 0:15 | N/A |
Values are mean ± SE. The values represent adjusted means based on the analysis of variance model including age, gender, and weight.
AT = anaerobic threshold; BR = breathing reserve; CPX = cardiopulmonary exercise testing; DP = double product; HR = heart rate; OUES = oxygen uptake efficiency slope; PETCO2 = end-tidal CO2; RER = respiratory exchange ratio; VE = minute ventilation; VO2 = oxygen uptake; VO2/WR slope = oxygen-uptake to work-rate relationship; other abbreviations as in Table 1.
Significant difference between COPD and healthy adults.
Significant difference between HFrEF and healthy adults.
Significant differences between all groups.
Significant difference between COPD and HFrEF.