J Clin Med Res

Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc

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Original Article

Volume 18, Number 9, September 2026, pages 661-670

Prognostic Significance of Serum Sodium in Patients With Acute Pulmonary Embolism

↓ Figure 1. Study flow diagram of patient selection and follow-up. ICD-10: International Classification of Diseases, 10th Revision; CTPA: computed tomography pulmonary angiography.

↓ Figure 2. Effect of PESI score on hazard ratio of death within 1 year. PESI: Pulmonary Embolism Severity Index.

↓ **Table 1.** Patient Characteristics
Characteristics	Non-survivors (1 year) (n=41)	Survivors (1 year) (n=64)	P value
^aThe institutional reference range for serum sodium was 135–145 mmol/L. APE: acute pulmonary embolism; BMI: body mass index; BW: body weight; COPD: chronic obstructive pulmonary disease; DBP: diastolic blood pressure; IQR: interquartile range; LOS: length of stay; MAP: mean arterial pressure; PESI: Pulmonary Embolism Severity Index; SBP: systolic blood pressure; VTE: venous thromboembolism.
Male, n (%)	17 (41.5%)	20 (31.3%)	0.303
Age (year), mean ± SD	66.9 ± 12.8	61.6 ± 20.6	0.143
BMI (kg/m²), mean ± SD	23.1 ± 5.1	25.8 ± 6.0	0.020
BW (kg), mean ± SD	58.9 ± 14.8	67.8 ± 20.7	0.020
Active cancer, n (%)	25 (61.0%)	10 (15.6%)	< 0.001
Comorbidity, n (%)
Diabetes	10 (24.4%)	19 (29.7%)	0.657
Heart failure	5 (12.2%)	9 (14.1%)	1.000
Hyperlipidemia	25 (61.0%)	33 (51.6%)	0.422
Cerebrovascular disease	6 (14.6%)	6 (9.4%)	0.532
Coronary artery disease	2 (4.9%)	4 (6.3%)	1.000
Previous VTE	2 (4.9%)	3 (4.7%)	1.000
COPD	9 (21.9%)	1 (1.6%)	0.001
Recent surgery/trauma status, n (%)
Trauma	1 (2.4%)	6 (9.4%)	0.162
Recent surgery	3 (7.3%)	10 (15.6%)	0.242
Hemodynamic data, mean ± SD
Heart rate	109.1 ± 20.5	99.9 ± 20.3	0.026
SBP	108.9 ± 25.9	130.8 ± 21.6	< 0.001
DBP	70.2 ± 15.5	79.3 ± 14.6	0.003
MAP	83.11 ± 17.8	96.5 ± 15.0	< 0.001
PESI score, mean ± SD	157.3 ± 56.0	91.0 ± 32.7	< 0.001
PESI classification, n (%)
Class I	0	10 (15.6%)	< 0.001
Class II	3 (7.3%)	14 (21.9%)
Class III	6 (14.6%)	24 (37.5%)
Class IV	5 (12.2%)	11 (17.2%)
Class V	27 (65.9%)	5 (7.8%)
Serum sodium at APE diagnosis^a, mean ± SD	130.6 ± 5.9	136.4 ± 4.4	< 0.001
Hyponatremia (Na < 135), n (%)	32 (78.1%)	23 (35.9%)	< 0.001
Serum troponin, median (IQR) (n = 27,50)	66.6 (36.2–89.5)	41.2 (12.0–81.9)	0.946
Severity of APE, n (%)
Low	1 (2.4%)	7 (10.9%)	< 0.001
Intermediate-low	10 (24.4%)	23 (35.9%)
Intermediate-high	14 (34.2%)	32 (50.0%)
High	16 (39.0%)	2 (3.2%)
LOS (day), median (IQR)	12.0 (6–21)	12.0 (8–19)	0.659
Follow-up time (day, median) (IQR)	25.0 (10–63)	785.5 (475–1,363)	< 0.001

↓ Table 1. Patient Characteristics

Characteristics

Non-survivors (1 year) (n=41)

Survivors (1 year) (n=64)

P value

^aThe institutional reference range for serum sodium was 135–145 mmol/L. APE: acute pulmonary embolism; BMI: body mass index; BW: body weight; COPD: chronic obstructive pulmonary disease; DBP: diastolic blood pressure; IQR: interquartile range; LOS: length of stay; MAP: mean arterial pressure; PESI: Pulmonary Embolism Severity Index; SBP: systolic blood pressure; VTE: venous thromboembolism.

Male, n (%)

17 (41.5%)

20 (31.3%)

0.303

Age (year), mean ± SD

66.9 ± 12.8

61.6 ± 20.6

0.143

BMI (kg/m²), mean ± SD

23.1 ± 5.1

25.8 ± 6.0

0.020

BW (kg), mean ± SD

58.9 ± 14.8

67.8 ± 20.7

0.020

Active cancer, n (%)

25 (61.0%)

10 (15.6%)

< 0.001

Comorbidity, n (%)

Diabetes

10 (24.4%)

19 (29.7%)

0.657

Heart failure

5 (12.2%)

9 (14.1%)

1.000

Hyperlipidemia

25 (61.0%)

33 (51.6%)

0.422

Cerebrovascular disease

6 (14.6%)

6 (9.4%)

0.532

Coronary artery disease

2 (4.9%)

4 (6.3%)

1.000

Previous VTE

2 (4.9%)

3 (4.7%)

1.000

COPD

9 (21.9%)

1 (1.6%)

0.001

Recent surgery/trauma status, n (%)

Trauma

1 (2.4%)

6 (9.4%)

0.162

Recent surgery

3 (7.3%)

10 (15.6%)

0.242

Hemodynamic data, mean ± SD

Heart rate

109.1 ± 20.5

99.9 ± 20.3

0.026

SBP

108.9 ± 25.9

130.8 ± 21.6

< 0.001

DBP

70.2 ± 15.5

79.3 ± 14.6

0.003

MAP

83.11 ± 17.8

96.5 ± 15.0

< 0.001

PESI score, mean ± SD

157.3 ± 56.0

91.0 ± 32.7

< 0.001

PESI classification, n (%)

Class I

10 (15.6%)

< 0.001

Class II

3 (7.3%)

14 (21.9%)

Class III

6 (14.6%)

24 (37.5%)

Class IV

5 (12.2%)

11 (17.2%)

Class V

27 (65.9%)

5 (7.8%)

Serum sodium at APE diagnosis^a, mean ± SD

130.6 ± 5.9

136.4 ± 4.4

< 0.001

Hyponatremia (Na < 135), n (%)

32 (78.1%)

23 (35.9%)

< 0.001

Serum troponin, median (IQR) (n = 27,50)

66.6 (36.2–89.5)

41.2 (12.0–81.9)

0.946

Severity of APE, n (%)

Low

1 (2.4%)

7 (10.9%)

< 0.001

Intermediate-low

10 (24.4%)

23 (35.9%)

Intermediate-high

14 (34.2%)

32 (50.0%)

High

16 (39.0%)

2 (3.2%)

LOS (day), median (IQR)

12.0 (6–21)

12.0 (8–19)

0.659

Follow-up time (day, median) (IQR)

25.0 (10–63)

785.5 (475–1,363)

< 0.001

↓ **Table 2.** Univariable Hazard Ratio (uHR) for 1-Year Mortality in Acute Pulmonary Embolism
Prognostic factors	uHR	95% CI	P value
^aNon-estimable due to zero n in reference category. APE: acute pulmonary embolism; BMI: body mass index; BW: body weight; COPD: chronic obstructive pulmonary disease; DBP: diastolic blood pressure; MAP: mean arterial pressure; PESI: Pulmonary Embolism Severity Index; SBP: systolic blood pressure; VTE: venous thromboembolism; CI: confidence interval; uHR: univariable hazard ratio.
Male	1.39	0.75, 2.60	0.294
Age (year)	1.01	0.99, 1.03	0.216
BMI (kg/m²)	0.93	0.87, 0.98	0.017
BW (kg)	0.98	0.96, 0.99	0.024
Active cancer	4.38	2.32, 8.27	< 0.001
Comorbidity
Heart failure	0.87	0.34, 2.21	0.762
Diabetes	0.82	0.40, 1.68	0.597
Cerebrovascular disease	1.45	0.61, 3.44	0.404
Coronary artery disease	0.90	0.22, 3.72	0.881
Previous VTE	1.08	0.26, 4.48	0.913
COPD	3.80	1.78, 8.11	0.001
Hemodynamic data
Heart rate	1.02	1.00, 1.03	0.021
SBP	0.96	0.95, 0.97	< 0.001
DBP	0.96	0.94, 0.98	0.001
MAP	0.96	0.94, 0.97	< 0.001
PESI score	1.01	1.01, 1.02	< 0.001
PESI classification^a	Non-estimable
Serum sodium at APE diagnosis (mmol/L)	0.86	0.81, 0.91	< 0.001
Hyponatremia (Na < 135 mmol/L)	4.20	2.00, 8.81	< 0.001
Serum troponin	1.0	0.99, 1.0	0.969
Severity of APE
Low	Reference	—	—
Intermediate-low	2.50	0.32, 19.53	0.383
Intermediate-high	2.54	0.33, 19.37	0.367
High	13.53	1.79, 102.48	0.012

↓ Table 2. Univariable Hazard Ratio (uHR) for 1-Year Mortality in Acute Pulmonary Embolism

Prognostic factors

uHR

95% CI

P value

^aNon-estimable due to zero n in reference category. APE: acute pulmonary embolism; BMI: body mass index; BW: body weight; COPD: chronic obstructive pulmonary disease; DBP: diastolic blood pressure; MAP: mean arterial pressure; PESI: Pulmonary Embolism Severity Index; SBP: systolic blood pressure; VTE: venous thromboembolism; CI: confidence interval; uHR: univariable hazard ratio.

Male

1.39

0.75, 2.60

0.294

Age (year)

1.01

0.99, 1.03

0.216

BMI (kg/m²)

0.93

0.87, 0.98

0.017

BW (kg)

0.98

0.96, 0.99

0.024

Active cancer

4.38

2.32, 8.27

< 0.001

Comorbidity

Heart failure

0.87

0.34, 2.21

0.762

Diabetes

0.82

0.40, 1.68

0.597

Cerebrovascular disease

1.45

0.61, 3.44

0.404

Coronary artery disease

0.90

0.22, 3.72

0.881

Previous VTE

1.08

0.26, 4.48

0.913

COPD

3.80

1.78, 8.11

0.001

Hemodynamic data

Heart rate

1.02

1.00, 1.03

0.021

SBP

0.96

0.95, 0.97

< 0.001

DBP

0.96

0.94, 0.98

0.001

MAP

0.96

0.94, 0.97

< 0.001

PESI score

1.01

1.01, 1.02

< 0.001

PESI classification^a

Non-estimable

Serum sodium at APE diagnosis (mmol/L)

0.86

0.81, 0.91

< 0.001

Hyponatremia (Na < 135 mmol/L)

4.20

2.00, 8.81

< 0.001

Serum troponin

1.0

0.99, 1.0

0.969

Severity of APE

Low

Reference

—

Intermediate-low

2.50

0.32, 19.53

0.383

Intermediate-high

2.54

0.33, 19.37

0.367

High

13.53

1.79, 102.48

0.012

↓ **Table 3.** Multivariable Hazard Ratios (mHRs) for 1-Year Mortality in Acute Pulmonary Embolism
Prognostic factors	mHR	95% CI	P value
The Cox proportional hazards regression model was adjusted for age, body weight, active cancer, chronic obstructive pulmonary disease, heart rate, systolic blood pressure, diastolic blood pressure, Pulmonary Embolism Severity Index score, and serum sodium at APE diagnosis. PESI classification was excluded because it was directly derived from the PESI score. BMI was excluded because of its strong correlation with body weight. APE: acute pulmonary embolism; BW: body weight; COPD: chronic obstructive pulmonary disease; PESI: Pulmonary Embolism Severity Index; CI: confidence interval; mHR: multivariable hazard ratio.
Age (per year)	0.98	0.95, 1.01	0.203
BW (per kg)	0.99	0.97, 1.01	0.172
Active cancer	1.73	0.75, 3.95	0.196
COPD	0.75	0.29, 1.98	0.565
Heart rate	0.99	0.98, 1.01	0.596
Systolic blood pressure (per mm Hg)	0.99	0.97, 1.02	0.840
Diastolic blood pressure (per mm Hg)	0.99	0.95, 1.02	0.404
PESI score (per 1-point increase)	1.01	1.00, 1.02	0.015
Serum sodium at APE diagnosis (per mmol/L)	0.92	0.86, 0.99	0.043

↓ Table 3. Multivariable Hazard Ratios (mHRs) for 1-Year Mortality in Acute Pulmonary Embolism

Prognostic factors

mHR

95% CI

P value

The Cox proportional hazards regression model was adjusted for age, body weight, active cancer, chronic obstructive pulmonary disease, heart rate, systolic blood pressure, diastolic blood pressure, Pulmonary Embolism Severity Index score, and serum sodium at APE diagnosis. PESI classification was excluded because it was directly derived from the PESI score. BMI was excluded because of its strong correlation with body weight. APE: acute pulmonary embolism; BW: body weight; COPD: chronic obstructive pulmonary disease; PESI: Pulmonary Embolism Severity Index; CI: confidence interval; mHR: multivariable hazard ratio.

Age (per year)

0.98

0.95, 1.01

0.203

BW (per kg)

0.99

0.97, 1.01

0.172

Active cancer

1.73

0.75, 3.95

0.196

COPD

0.75

0.29, 1.98

0.565

Heart rate

0.99

0.98, 1.01

0.596

Systolic blood pressure (per mm Hg)

0.99

0.97, 1.02

0.840

Diastolic blood pressure (per mm Hg)

0.99

0.95, 1.02

0.404

PESI score (per 1-point increase)

1.01

1.00, 1.02

0.015

Serum sodium at APE diagnosis (per mmol/L)

0.92

0.86, 0.99

0.043