TABLE 3.
Association between Variables Measured during CPX Testing and Mortality (Univariate Analyses)
| Parameters | Hazard Ratio (95% Confidence Interval) | Wald chi-square* | c-index (Optimism Corrected) |
|---|---|---|---|
|
| |||
| Percent predicted peak VO2, per 5% change | |||
| All | 0.81 (0.78–0.84) | 141 | 0.690 (0.661– 0.719) |
| Men | 0.81 (0.78–0.85) | 100 | 0.678 (0.646–0.712) |
| Women | 0.82 (0.76–0.89) | 30 | 0.690 (0.628–0.753) |
|
| |||
| Exercise duration, min | |||
| All | 0.83 (0.80–0.85) | 142 | 0.689 (0.660–0.718) |
| Men | 0.83 (0.80–0.85) | 117 | 0.700 (0.669–0.731) |
| Women | 0.78 (0.73–0.84) | 41 | 0.710 (0.641–0.779) |
|
| |||
| Relative peak VO2, mL·kg−1·min−1 | |||
| All | 0.85 (0.83–0.87) | 130 | 0.684 (0.655–0.713) |
| Men | 0.83 (0.81–0.86) | 129 | 0.708 (0.676–0.740) |
| Women | 0.84 (0.78–0.90) | 25 | 0.673 (0.605–0.740) |
|
| |||
| Absolute peak VO2, per 100 ml/min−1 | |||
| All | 0.88 (0.86–0.90) | 96 | 0.663 (0.632–0.694) |
| Men | 0.86 (0.84–0.89) | 109 | 0.689 (0.656–0.722) |
| Women | 0.79 (0.73–0.86) | 30 | 0.700 (0.634–0.766) |
|
| |||
| Peak respiratory exchange ratio, per 0.1 units | |||
| All | 0.97 (0.88–1.07) | 1 (p=0.50) | 0.501 (0.469–0.533) |
| Men | 0.96 (0.86–1.07) | 1 (p=0.47) | 0.507 (0.472–0.543) |
| Women | 0.84 (0.68–1.05) | 2 (p=0.12) | 0.527 (0.453–0.601) |
|
| |||
| Ventilatory efficiency (VE – VCO2 slope), per 5 units | |||
| All | 1.29 (1.23–1.34) | 133 | 0.648 (0.616–0.68) |
| Men | 1.27 (1.21–1.33) | 99 | 0.641 (0.605–0.677) |
| Women | 1.34 (1.20–1.49) | 28 | 0.668 (0.592–0.743) |
|
| |||
| Heart rate reserve, per 5 beats/min−1 | |||
| All | 0.87 (0.85–0.90) | 103 | 0.660 (0.630–0.689) |
| Men | 0.88 (0.85–0.90) | 73 | 0.656 (0.623–0.688) |
| Women | 0.87 (0.82–0.92) | 22 | 0.643 (0.567–0.719) |
|
| |||
| VO2 at VAT, mL·kg−1·min−1 | |||
| All | 0.83 (0.78–0.87) | 56 | 0.640 (0.606–0.674) |
| Men | 0.80 (0.76–0.85) | 60 | 0.659 (0.621–0.697) |
| Women | 0.83 (0.72–0.95) | 8 (p=0.005) | 0.627 (0.545–0.710) |
|
| |||
| Peak oxygen pulse, ml/beat−1 | |||
| All | 0.90 (0.88–0.93) | 43 | 0.611 (0.580–0.643) |
| Men | 0.86 (0.83–0.89) | 72 | 0.653 (0.618–0.687) |
| Women | 0.83 (0.75–0.92) | 13 | 0.637 (0.572–0.703) |
|
| |||
| Oxygen uptake efficiency slope (all data), per 100 units | |||
| All | 0.94 (0.90–0.93) | 75 | 0.639 (0.607–0.671) |
| Men | 0.90 (0.89–0.92) | 84 | 0.657 (0.622–0.693) |
| Women | 0.85 (0.80–0.91) | 25 | 0.698 (0.635–0.761) |
*
p values significant at p< 0.0001 except where otherwise indicated.
CPX = cardiopulmonary exercise; other abbreviations as in Table 2.