Table 2 Prior treatment data on the two patient groups

Age(years)

65.1 ± 7.5

66.0 ± 7.1

0.355

Male gender(n, %)

73 (42.44)

49 (56.32)

0.095

Body mass index(kg/m²)

23.52 ± 2.72

23.88 ± 2.52

0.314

Time interval the first surgery(years)

11.0(6.0, 14.0)

12.0(7.0, 13.0)

0.903

Heart rate(beats/minute)

83.3 ± 13.9

84.4 ± 17.8

0.623

Cardiac function grade

NYHA I(n, %)

0 (0.00)

0 (0.00)

N/A

NYHA II(n, %)

25(14.53)

11(12.64)

0.918

NYHA III(n, %)

133 (77.33)

68 (78.16)

0.995

NYHA IV(n, %)

14 (8.14)

8 (9.20)

0.985

Hypertension(n, %)

68 (39.53)

40 (45.98)

0.496

SBP(mmHg)

127.28 ± 19.75

125.11 ± 15.60

0.470

DBP(mmHg)

78.80 ± 15.97

79.28 ± 14.60

0.127

Atrial fibrillation(n, %)

34 (19.77)

11 (12.64)

0.521

Diabetes mellitus(n, %)

36 (20.93)

14 (16.09)

0.680

Coronary heart disease(n, %)

11 (6.40)

6 (6.80)

0.972

LVEF(%)

37.92 ± 4.68

36.90 ± 5.91

0.162

LEVDD(mm)

54.13 ± 6.90

54.87 ± 6.80

0.415

LVESD(mm)

42.67 ± 7.82

43.86 ± 7.45

0.242

Left atrial size(mm)

44.00 ± 7.74

42.69 ± 7.10

0.186

Cardiac output(L/min)

5.0(3.5, 6.0)

5.0(4.1, 5.5)

0.415

Artificial valve disorder(n, %)

0 (0.00)

0 (0.00)

N/A

Mild mitral insufficiency(n, %)

5 (2.91)

2 (2.30)

0.904

Moderate mitral insufficiency(n, %)

0 (0.00)

0 (0.00)

N/A

Severe mitral insufficiency(n, %)

0 (0.00)

0 (0.00)

N/A

Mild tricuspid insufficiency(n, %)

7 (4.07)

3 (3.45)

0.923

moderate tricuspid insufficiency(n, %)

2 (1.16)

1 (1.15)

0.545

Severe tricuspid insufficiency(n, %)

0 (0.00)

0 (0.00)

N/A

Hemoglobin(g/L)

122.93 ± 17.25

122.84 ± 14.90

0.967

Hematocrit(%)

39.46 ± 6.33

38.87 ± 4.08

0.396

NT-ProBNP(pg/ml)

1399.0(775.0, 2814.0)

1028.0(769.0, 2307.0)

0.249

serum creatinine(umol/L)

75.80 ± 28.32

78.70 ± 32.39

0.459

Alanine aminotransferase(IU/L)

28.31 ± 24.73

30.29 ± 27.87

0.382

Aspartate aminotransferase(IU/L)

33.55 ± 23.57

33.70 ± 23.96

0.960

Blood glucose(mmol/L)

5.47 ± 1.66

5.36 ± 1.43

0.573

Potassium ion(mmol/L)

4.05 ± 0.50

3.95 ± 0.50

0.157

Sodium ion(mmol/L)

140.51 ± 3.33

141.03 ± 2.29

0.140

Length of stay(d)

9.9 ± 5.1

11.1 ± 5.8

0.075