Table 1.
Baseline characteristics and relevant cardiopulmonary exercise data. Data are presented as %, mean (standard deviation), or median (inter-quartile range [IQR]). Data adapted from Singh and colleagues.4 FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; SaO2, oxygen saturation in arterial blood; DO2, oxygen delivery; VO2, oxygen consumption; EO2, oxygen extraction ratio, CPET, cardiopulmonary exercise testing.
| Post-COVID-19 (n=10) | Controls (n=10) | P-value | |
|---|---|---|---|
| Characteristics | |||
| Age, yr (range) | 48 (28–79) | 48 (40–68) | 0.87 |
| Female/male | 9/1 | 8/2 | 0.53 |
| BMI (kg m−2) | 28 (6) | 24 (6) | 0.11 |
| Haemoglobin (g dl−1) | 13.4 (1.1) | 14.2 (1.4) | 0.16 |
| Interval time from acute infection (months) | 11 (1) | Not applicable | |
| Pulmonary function tests | |||
| FEV1 (% predicted) | 97 (1) | 100 (1) | 0.34 |
| FVC (% predicted) | 96 (1) | 104 (1) | 0.19 |
| FEV1/FVC (% predicted) | 101 (3) | 98 (5) | 0.18 |
| CPET – resting | |||
| SaO2 (%) | 98 (IQR 97–98) | 98 (IQR 97–98) | 0.64 |
| Mixed venous O2 saturation (%) | 73 (3) | 66 (6) | 0.01 |
| Stroke volume index (ml m−2) | 36.3 (10.3) | 40.3 (12.8) | 0.44 |
| Cardiac index (L min−1 m−2) | 3.2 (0.6) | 2.8 (0.5) | 0.13 |
| DO2 (ml kg−1 min−1) | 1.41 (0.24) | 1.24 (0.35) | 0.23 |
| VO2 (ml min−1 kg−1) | 3.69 (0.5) | 4.38 (0.8) | 0.04 |
| Systemic EO2 (ratio) | 0.26 (0.03) | 0.36 (0.01) | 0.01 |
| CPET – peak exercise | |||
| VO2 (ml min−1 kg−1) | 16.7 (4.2) | 33.5 (12.9) | 0.001 |
| Heart rate (% predicted) | 84 (8) | 84 (2) | 0.85 |
| SaO2 (%) | 98 (IQR 98–98) | 97 (IQR 97–98) | 0.01 |
| Mixed venous O2 saturation %) | 50 (10) | 22 (5) | <0.0001 |
| DO2 (ml kg−1 min−1) | 3.6 (1.4) | 4.2 (1.5) | 0.33 |
| Systemic EO2 (ratio) | 0.49 (0.1) | 0.78 (0.1) | <0.0001 |
| Cardiac index (L min−1 m−2) | 7.8 (3.1) | 8.4 (2.3) | 0.59 |
| Stroke volume index (ml m−2) | 54.1 (20.8) | 63.5 (22.2) | 0.34 |