Importance of physical capacity and the effects of exercise in heart transplant recipients

Figure 1 Physical capacity, as assessed by VO_2peak after heart transplantation from published studies, illustrated by years after surgery. Black line at 12 mL/kg per minute, show the threshold to be candidates for HTx, dotted line at 20 mL/min per kilogram, show the start of Weber function class A, representing good physical condition. The measurements are carried out from exercise tests from; Bernandi et al[85], Carter et al[86], Dall et al[35], Ewert et al[87], Givertz et al[88], Gullestad et al[89], Habedank et al[90], Haykowski et al[91], Hermann et al[36], Hognestad et al[92], Karpolat et al[93], Kavanagh et al[94], Kemp et al[95], Kobashigawa et al[96], Nytrøen et al[37], Osada et al[5], Renlund et al[97], Schwaiblmair et al[98], Squires et al[99], Tegtbur et al[100], Wu et al[77]. HTx: Heart transplantation.

Figure 2 Illustration of the increase in peak VO₂ from pre heart transplantation to 36 mo post heart transplantation. The data presented in the figure is from the unpublished Schedule trial.

Figure 3 Illustration of two different exercise modalities. A: Illustration of a session with high-intensity interval training (HIT). HIT is an exercise strategy with alternating short periods of intense endurance exercise with less-intense recovery periods. A usual HIT session may include 4 × 4 min periods with high intensity (85%-95% of maximal capacity), with active recovery periods of 3min between each interval (with 60%-70% of maximal capacity); B: Illustration of a session with moderate intensity continuous training (MICT). MICT is an exercise strategy with moderate intensity (60%-70% of maximal capacity) of endurance exercise in periods for usually 25-30 min, with no recovery periods.

Figure 4 Heart rate during exercise 3 mo post heart transplantation. Patient from our hospital, 3 mo post-HTx: HR curve during warm-up, two high-intensity intervals divided by one recovery period and cool-down. The curve shows a typical pattern of impaired HR responses in the early stage after HTx. HTx: Heart transplantation.

Figure 5 Heart rate during exercise 12 mo post heart transplantation. The same patient 12 mo post-HTx: Heart rate curve during warm-up four high-intensity intervals divided by 3 recovery periods and cool-down. The curve shows a largely normalized HR, with immediate HR adaptions to exercise intensity. HTx: Heart transplantation.

Figure 6 Measurements of VO_2peak at baseline, 1-year and 5-year follow-up. ¹Significant changes between groups; ²Significant changes from baseline to 5-year follow-up within group.