Table 1 Baseline characteristics.

Age, y

66 (29-84)

66 (36-88)

NS

1.007 (0.989–1.024)

0.450

 Male

151 (60.4)

162 (52.3)

NS

1.393 (0.994–1.953)

0.054

 Female

99 (39.6)

148 (47.7)

Performance status

 ECOG 0-2

238 (95.2)

301 (97.1)

NS

Reference category

 ECOG > 2

12 (4.8)

9 (2.9)

1.686 (0.699–4.069)

0.245

 Cardiac involvement

149 (59.6)

164 (52.9)

NS

1.313 (0.938–1.840)

0.113

Mayo stage (European modification)

I

39 (12.6)

74 (23.9)

0.01

0.589 (0.383–0.906)

0.016

II

102 (40.8)

116 (37.4)

NS

1.153 (0.819–1.622)

0.415

IIIa

81 (32.4)

99 (31.9)

NS

1.022 (0.715–1.459)

0.907

IIIb

28 (11.2)

21 (6.8)

NS

1.736 (0.960–3.138)

0.068

Revised Mayo stage

 I

31 (12.4)

82 (26.5)

<0.005

0.394 (0.250–0.619)

<0.005

 II

76 (30.4)

94 (30.3)

NS

1.004 (0.699–1.442)

0.984

 III

76 (30.4)

84 (27.1)

NS

1.175 (0.813–1.698)

0.390

 IV

67 (26.8)

50 (16.1)

<0.005

1.904 (1.261–2.875)

0.002

 NT-proBNP, ng/L

1353 (12–37290)

474 (4–93602)

<0.005

1.884 (1.512–2.348)

<0.005

 High-sensitivity cardiac troponin T, ng/L

47 (3–742)

38 (1–689)

0.012

1.554 (1.096–2.202)

0.013

 Renal involvement

172 (68.8)

225 (72.6)

NS

0.833 (0.578–1.201)

0.328

 Serum creatinine, µmol/L

96 (40–1124)

96 (27–610)

NS

1.000 (0.998–1.002)

0.992

 Proteinuria, g/24 h

2.8 (0–29.8)

3.8 (0.1–36)

NS

0.988 (0.954–1.023)

0.484

 Liver involvement

24 (9.6)

47 (15.2)

0.049

0.594 (0.352–1.002)

0.051

 Alkaline Phosphatase, U/L

82 (41–1035)

88 (16–1178)

NS

0.999 (0.997–1.000)

0.060

 GI Involvement

11 (4.4)

8 (2.6)

NS

1.737 (0.688–4.388)

0.243

 Autonomic nervous system involvement

19 (7.6)

16 (5.2)

NS

1.511 (0.760–3.004)

0.239

 Peripheral nervous system involvement

19 (7.6)

17 (5.5)

NS

1.418 (0.721–2.789)

0.312

 Soft tissue involvement

46 (18.4)

40 (12.9)

NS

1.522 (0.960–2.414)

0.074

Heavy chain isotype

 IgA

42 (16.8)

45 (14.5)

NS

1.189 (0.752–1.880)

0.459

 IgD

1 (0.4)

1 (0.3)

NS

1.241 (0.077–19.940)

0.879

 IgG

87 (34.8)

106 (34.2)

NS

1.027 (0.724–1.458)

0.881

 IgM

4 (1.6)

8 (2.6)

NS

0.614 (0.183–2.063)

0.430

 LC

57 (22.8)

67 (21.6)

NS

1.071 (0.718–1.599)

0.737

 None

59 (23.6)

83 (26.8)

NS

0.845 (0.575–1.242)

0.391

Serum monoclonal protein, g/L

9 (IF-45)

6.5 (IF-38)

0.023

2.110 (1.104–4.032)

0.024

2.636 (1.033–6.732)

0.012

Light chain isotype

 Kappa

56 (22.4)

60 (19.4)

NS

Reference category

 Lambda

194 (77.6)

250 (80.6)

0.831 (0.552–1.252)

0.377

 dFLC, mg/L

205 (1–13007)

128.8 (1–5316)

<0.005

1.938 (1.458–2.578)

<0.005

 dFLC > 180 mg/l

138 (55.2)

121 (39)

<0.005

1.925 (1.373–2.698)

<0.005

 dFLC > 500 mg/l

66 (26.4)

49 (15.8)

0.002

1.911 (1.262–2.893)

0.002

 dFLC > 1000 mg/l

31 (12.4)

16 (5.2)

0.002

2.601 (1.388–4.875)

0.003

 FLC ratio ≥ 100

33 (13.2)

20 (6.5)

0.006

2.205 (1.231–3.949)

0.008

 Bone marrow plasma cells at diagnosis (morphology)

n = 174 10 (1–90)

n = 226 10 (1–95)

NS

1.644 (0.985–2.745)

0.057

 Bone marrow plasma cells >10%

116 (66.7)

130 (57.5)

NS

1.477 (0.979–2.228)

0.063

 Bone marrow plasma cells > 20%

59 (33.9)

53 (23.5)

0.02

1.675 (1.079–2.599)

0.021

 Number of cycles of chemotherapy (1st line)

6 (2-9)

6 (2-11)

NS

 ≥VGPR after 1^st line

153 (61.2)

270 (87.1)

<0.005

0.234 (0.154–0.355)

<0.005

 dFLC < 10 mg/l after 1st line

59 (23.6)

214 (69)

<0.005

0.139 (0.095–0.202)

<0.005

0.122 (0.063–0.235)

<0.005

 iFLC < 20 mg/l after 1st line

40 (16)

153 (49.4)

<0.005

0.195 (0.130–0.293)

<0.005