Table 1 Functional and morphological characteristics of sham, TAC_SED and TAC_EX

Baseline TAC phenotype

 Body weight (g)

28.2 ± 0.1

28.2 ± 0.2 (p = 0.13)

29.2 ± 0.1 (a: p = 0.95; b: p = 0.18)

 Tibia length (mm)

17.2 ± 0.05

17.5 ± 0.03 (p = 0.89)

17.2 ± 0.05 (a: p = 0.10; b: p = 0.12)

 Heart weight (mg)

145.6 ± 1.0

201.4 ± 2.8 (p < 0.001)

213.8 ± 2.8 (a: p < 0.001; b: p = 0.46)

 Heart weight/tibia length (mg/mm)

8.5 ± 0.1

11.6 ± 0.1 (p < 0.001)

12.4 ± 0.2 (a: p < 0.001; b: p = 0.26)

 EDL mass/TL (mg/mm)

0.77 ± 0.12

0.83 ± 0.05 (p = 0.14)

0.81 ± 0.05 (a: p = 0.35; b: p = 0.61)

Functional cardiac parameters

 LCCA velocity 2 weeks post TAC (mm/s)

833.5 ± 15.3

333.0 ± 49.5 (a: p < 0.001; b: p = 0.90)

 RCCA velocity 2 weeks post TAC (mm/s)

1148.7 ± 154.4

1524.1 ± 138.0 (a: p = 0.098; b: p = 0.42)

 LVEF (%)

61 ± 5

46 ± 6 (p < 0.001)

47 ± 7 (a: p < 0.001; b: p = 0.76)

 FS (%)

32 ± 3

22 ± 4 (p < 0.001)

23 ± 4 (a: p < 0.001; b: p = 0.76)

 Diastolic LV volume (µL)

68.7 ± 5.58

103.9 ± 4.9 (p = 0.002)

107.1 ± 9.6 (a: p = 0.03; b: p = 0.77)

 Systolic LV volume (µL)

34.6 ± 4.0

63.4 ± 5.5 (p < 0.001)

69.4 ± 10.9 (a: p = 0.007; b: p = 0.63)

 Diastolic LV wall thickness (mm)

4.3 ± 0.1

4.7 ± 0.9 (p = 0.27)

4.4 ± 0.4 (a: p = 0.097; b: p = 0.69)

 Systolic LV wall thickness (mm)

1.0 ± 0.1

1.1 ± 0.1 (p = 0.64)

1.1 ± 0.1 (a: p = 0.50; b: p = 0.82)

Histological evaluation of cardiac remodeling

 Relative heart area

1

0.98 ± 0.05 (p = 0.72)

1.09 ± 0.03 (a: p = 0.022; b: p = 0.053)

 Relative circumference

1

0.98 ± 0.02 (p = 0.45)

1.07 ± 0.02 (a: p = 0.01; b: p = 0.003)

 Relative LV thickness

1

1.09 ± 0.08 (p = 0.40)

1.09 ± 0.06 (a: p = 0.23; b:p = 0.97)

 Relative RV thickness

1

0.77 ± 0.08 (p = 0.044)

0.70 ± 0.06 (a:p = 0.004; b: p = 0.56)

 Cardiomyocyte CSA (µm²)

50.3 ± 0.8

61.6 ± 1.2 (p < 0.001)

59.6 ± 1.0 (a: p < 0.001; b: p = 0.20)

 Perivascular fibrosis (%)

1.8 ± 0.1

2.0 ± 1.1 (p = 0.75)

2.6 ± 0.2 (a:p = 0.27; b:p = 0.48)

 Interstitial fibrosis (%)

0.2 ± 0.1

0.4 ± 0.1 (p = 0.51)

0.3 ± 0.1 (a: p = 0.01; b: p = 0.86)

 Coronary artery diameter (µm)

27.3 ± 2.0

36.6 ± 2.8 (p = 0.008)

30.8 ± 3.0 (a: p = 0.32; b: p = 0.16)

Muscle function and remodeling

 EDL max. force (N/cm²)

25.8 ± 5.7

28.8 ± 4.7 (p = 0.20)

28.1 ± 6.6 (a: p = 0.30; b: p = 0.9)

 EDL fiber diameter (µm)

40.7 ± 1.7

35.3 ± 1.6 (p = 0.04)

37.1 ± 1.4 (a: p = 0.16, b: p = 0.79)

 EDL slow fiber proportion (%)

2.25 ± 0.41

1.81 ± 0.48 (p = 0.78)

2.63 ± 1.12 (a: p = 0.62; b: p = 0.53)

 EDL fast fiber proportion (%)

92.7 ± 1.1

86.6 ± 07.2 (p = 0.32)

93.1 ± 4.6 (a: p = 0.84; b: p = 021)

 Soleus fiber diameter (µm)

44.3 ± 1.9

45.8 ± 1.5 (p = 0.74)

37.8 ± 1.5 (a: p = 0.01; b: p = 0.002)

 Soleus slow fiber proportion (%)

30.3 ± 3.0

33.6 ± 8.5 (p = 0.73)

29.7 ± 2.6 (a: p = 0.87; b: p = 0.78)