Table 2 Comparison of echocardiography-directed management (ECDM) and control groups in the cohort of patients with birth weight ≤ 1500 g at baseline

GA (week)

29.39

1.69

32.93

2.58

3.55

2.27 to 4.82

 < 0.0001

BW (kg)

1.10

0.17

1.37

0.11

0.27

0.17 to 0.36

 < 0.0001

HR (bpm)

144.52

21.03

133.27

20.66

 − 11.25

 − 24.51 to 2.01

0.094

LVOT (cm²)

0.32

0.04

0.28

0.04

 − 0.04

 − 0.06 to − 0.01

0.007

LVTI

10.92

2.28

10.06

1.15

 − 0.86

 − 2.13 to 0.40

0.177

LVO (ml/kg/min)

474.09

152.10

277.26

63.96

 − 196.83

 − 279.82 to − 113.84

 < 0.0001

RVOT (cm²)

0.33

0.05

0.28

0.05

 − 0.05

 − 0.08 to − 0.02

0.005

RVTI

10.77

2.44

10.99

1.27

0.22

 − 1.1453 to 1.58

0.751

RVO (ml/kg/min)

479.37

154.13

303.08

74.62

 − 176.29

 − 261.45 to − 91.12

0.0001

FS (%)

34.37

3.75

31.97

3.03

 − 2.41

 − 4.67 to − 0.14

0.038

EF (%)

67.52

5.84

64.00

4.77

 − 3.52

 − 7.05 to 0.02

0.051

TAPSE (cm)

0.64

0.08

0.65

0.08

0.01

 − 0.04 to 0.07

0.664

MAPSE (cm)

0.42

0.06

0.43

0.06

0.01

 − 0.03 to 0.05

0.586