Table 2.
Effect of exercise in the two study populations < 40 years of age
| The HITTS study (n = 16) | The TEX study (n = 12) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| HIT group (n = 6) Mean ± SD or median (IR) |
MICT group (n = 10) Mean ± SD or median (IR) |
Mean difference between groups [95%CI] | t-test p-value | HIT group (n = 8) Mean ± SD |
Control group (n = 4) Mean ± SD |
Mean difference between groups [95%CI] | t-test p-value | |||||
| Baseline | Follow-up | Baseline | Follow-up | Baseline | Follow-up | Baseline | Follow-up | |||||
| VO2peak (ml/kg/min) | 22.3 ± 5.6 | 30.0 ± 8.9 | 24.0 ± 6.0 | 27.0 ± 7.7 | 4.7 [0.6, 8.8] | 0.028 | 27.0 ± 4.7 | 32.5 ± 4.5 | 33.0 ± 8.0 | 31.5 ± 5.1 | 7.0 [2.6, 11.3] | 0.005 |
| %VO2exp | 51.3 ± 12.9 | 69.9 ± 20.4 | 59.7 ± 13.6 | 67.5 ± 16.5 | 11 [1, 20] | 0.030 | 66.3 ± 9.6 | 81.2 ± 13.3 | 82.5 ± 17.6 | 79.4 ± 10.3, | 18.0 [5.9, 30.0] | 0.008 |
| O2 pulse | 13.0 ± 3.0 | 15.4 ± 3.3 | 12.0 ± 2.6 | 11.7 ± 2.9 | 2.7 [− 0.1, 5.6] | 0.060 | 15.1 ± 3.7 | 16.3 ± 2.8 | 16.7 ± 5.3 | 16.6 ± 4.3 | 1.4 [− 0.5, 3.2] | 0.132 |
| HR rest echo | 91 ± 8 | 91 ± 10 | 83 ± 7 | 91 ± 8 | 8 [0, 17] | 0.053 | 85 ± 16 | 80 ± 12 | 75 ± 12 | 84 ± 17 | − 14 [− 22, − 6] | 0.003 |
| HR peak | 127 (29) | 161 (43) | 136 (39) | 166 (30) | 0.064† | 156 ± 15 | 165 ± 17 | 163 ± 16 | 165 ± 18 | 7 [− 8, 15] | 0.073 | |
| %HR max | 68 ± 6 | 81 ± 8 | 69 ± 11 | 84 ± 11 | 1 [− 7, 9] | 0.731 | 81 ± 7 | 86 ± 8 | 85 ± 11 | 87 ± 10 | 4 [− 1, 8] | 0.085 |
| Chronotropic response index | 0.38 ± 0.12 | 0.63 ± 0.20 | 0.47 ± 0.17 | 0.70 ± 0.24 | 0.02 [− 0.15, 0.19] | 0.770 | 0.67 ± 0.11 | 0.77 ± 0.12 | 0.77 ± 0.14 | 0.77 ± 0.16 | 0.09 [0.01, 0.17] | 0.031 |
| HR recovery 2 min (bpm) | −2 ± 3 | −14 ± 12 | −3 ± 2 | − 23 ± 10 | −9 [− 21, 3] | 0.141 | − 22 ± 5 | −30 ± 6 | − 39 ± 5 | − 38 ± 10 | − 8 [− 17, 0] | 0.069 |
| Quadriceps muscular exercise capacity (J) | 2944 (3017) | 3284 (2961) | 1649 (1774) | 2524 (2824) | 0.162† | 2813 ± 2042 | 3572 ± 1598, | 3605 ± 1675 | 3697 ± 1138 | 667 [− 382, 1716] | 0.187 | |
| Quadriceps maximum strength (Nm) | 216 (124) | 288 (136) | 172 (143) | 201 (175) | 0.006† | 240 ± 117 | 264 ± 111 | 279 ± 90 | 262 ± 83 | 41 [5, 77] | 0.031 | |
| BMI | 23.5 ± 4.4 | 24.6 ± 4.9 | 23.2 ± 4.4 | 24.1 ± 4.9 | 0.2 [− 1.9, 2.2] | 0.858 | 27.4 ± 5.1 | 25.8 ± 4.6 | 25.7 ± 3.5 | 25.4 ± 2.3 | − 1.2 [− 4.4, 1.9] | 0.410 |
† Mann Whitney U-test
SD Standard deviation, IR Interquartile range, HITTS High-intensity Interval Training in heart Transplant recipients in Scandinavia, TEX Transplant EXercise, HIT High-intensity interval training, MICT Moderate intensity continuous training; %VO2exp, percentage of expected VO2 peak level according to age; HR Heart rate; %HR max, percentage of maximum HR according to age; J Joule, Nm Newton meter