3.1. Baseline Characteristics of the Patients
206 patients were included in this study. Each patient received a surgical operation. Clinical features of survivors and the dead patients were summarized in Table 1. In our study, the indicators including D-dimer, FIB, WBC, NEU, PLT and CRP in the death group were significantly different from those in the survival group. Furthermore, there were no significant differences regarding gender, hypertension, dyslipidemia, diabetes, smoking, alcohol abuse, hemoglobin, ALT, AST, EF, and Cr between the two groups. Additionally, no significant difference in surgical time, CPB time, cross-clamp time and HCA time was observed between the two groups.
Table 1
Baseline characteristics between the death group and the survival group.
Variable
|
Non-survivor (n = 28)
|
Survivor(n = 178)
|
P Value
|
Age (years)
|
52.3 ± 12.38
|
51.84 ± 10.88
|
0.842
|
Female/Male
|
5/23
|
32/146
|
0.770
|
Hypertension, n (%)
|
11 (39.3)
|
87 (48.9)
|
0.123
|
History of smoking, n (%)
|
10 (35.7)
|
65 (36.5)
|
0.590
|
Alcohol consumption,
n (%)
|
6 (21.4)
|
35 (19.7)
|
0.671
|
Diabetes mellitus, n (%)
|
1 (3.6)
|
5 (2.8)
|
0.911
|
ALT (U/L)
|
32.31 ± 27.11
|
30.76 ± 20.23
|
0.130
|
AST (U/L)
|
39.58 ± 25.42
|
38.97 ± 21.35
|
0.074
|
BUN (mmol/L)
|
7.4 ± 2.96
|
6.78 ± 2.52
|
0.242
|
Cr (umol/L)
|
69 ~ 139
|
55 ~ 95
|
0.081
|
Mb (ng/mL)
|
67 ~ 950
|
45 ~ 152.25
|
0.071
|
EF (%)
|
51.25 ± 3.47
|
51.82 ± 2.75
|
0.788
|
D-Dimer (mg/L)
|
23.04 ± 17.69
|
12.66 ± 11.38
|
0.040
|
INR
|
1.23 ± 0.54
|
1.15 ± 0.21
|
0.444
|
FDP (mg/L)
|
69.08 ± 26.74
|
42.84 ± 26.59
|
0.069
|
FIB (g/L)
|
2.12 ± 1.51
|
2.93 ± 1.72
|
0.041
|
Cys-C ( mg/L)
|
1.14 ± 0.66
|
0.91 ± 0.35
|
0.085
|
Hb (g/L)
|
130.12 ± 30.24
|
133.91 ± 14.65
|
0.508
|
White blood cell (×109/L)
|
13.96 ± 4.76
|
11.53 ± 4.32
|
0.046
|
Neutrophil (×109/L)
|
11.93 ± 3.70
|
9.98 ± 4.17
|
0.024
|
Platelet (×109/L)
|
136.25 ± 64.31
|
174.31 ± 61.75
|
0.003
|
CRP (mg/L)
|
34.64 ± 23.96
|
29.18 ± 24.31
|
0.041
|
Data are mean ± SD, or median (interquartile range), n (%). |
ALT, alamine aminotransferase; AST, aspartate transaminase; BUN, blood urea nitrogen; Cr, creatinine; Mb, myoglobin; EF, ejection fraction; INR, international normalized ratio; FDP, fibrinogen degradation product; FIB, fibrinogen; Hb, hemoglobin; Cys-C, Cystatin C; CRP, C reactive protein. |
3.2 ROC Analysis
The predictive value of D-dimer, FIB, PLT, CRP, WBC and NEU for in-hospital deaths was evaluated by using the receiver operating characteristic (ROC) method, as shown in Table 2. The area under the ROC curve (AUC) of D-Dimer was 0.647 [95% (0.573, 0.716)], and the sensitivity and specificity was 63.0% and 65.2%, respectively (P = 0.0128). The AUC of FIB was 0.634 [95% (0.562, 0.705)], and the sensitivity and specificity was 59.3% and 69.6%, respectively (P = 0.0221).The AUC of PLT was 0.684 [95% (0.611, 0.750)], and the sensitivity and specificity was 48.2% and 84.2%, respectively (P = 0.0028).The AUC of CRP was 0.542 [95% (0.468, 0.616)], and the sensitivity and specificity was 70.4% and 41.1%, respectively (P = 0.4560).The AUC of WBC was 0.641[95% (0.567, 0.710)], and the sensitivity and specificity was 55.6% and 72.8%, respectively (P = 0.0109). The AUC of NEU was 0.653 [95% (0.580, 0.721)], and the sensitivity and specificity was 55.6% and 75.3%, respectively (P = 0.0128).
Table 2
Diagnostic value of D-dimer, FIB, PLT, CRP, WBC and NEU for in-hospital mortality.
Variable
|
AUC
|
Cut-off value
|
SE
|
95% CI
|
Sensitivity
|
Specificity
|
P value
|
D-dimer
|
0.647
|
> 10.3
|
0.0590
|
0.573–0.716
|
0.630
|
0.652
|
0.0128
|
FIB
|
0.636
|
≤ 2.12
|
0.0593
|
0.562–0.705
|
0.593
|
0.696
|
0.0221
|
PLT
|
0.684
|
≤ 122
|
0.0615
|
0.611–0.750
|
0.482
|
0.842
|
0.0028
|
CRP
|
0.542
|
> 11
|
0.0569
|
0.468–0.616
|
0.704
|
0.411
|
0.4560
|
WBC
|
0.641
|
> 13.17
|
0.0554
|
0.567–0.710
|
0.556
|
0.728
|
0.0109
|
NEU
|
0.653
|
> 11.94
|
0.0532
|
0.580–0.721
|
0.556
|
0.753
|
0.0041
|
FIB, fibrinogen; PLT: platelet; CRP, C reactive protein; WBC, white blood cells; NEU, neutrophil. |
It can be seen from the ROC analysis results that PLT had the highest specificity, while CRP was provided with the highest sensitivity. Therefore, as shown in Table 3, Fig. 1 and Fig. 2, using ROC method, we further evaluated the predictive value for in-hospital deaths by combining PLT or CRP with other indicators in pairs, respectively. As can be seen from the results in Table 4, FIB + PLT combination is provided with the highest predictive value for in-hospital deaths due to its greatest value of AUC among all the kinds of these combinations. The AUC of FIB + PLT combination was 0.722 [95% (0.651, 0.785)], and the sensitivity and specificity was 59.26% and 80.38%, respectively (P = 0.0001). The AUC of D-dimer + CRP combination was 0.686 [95% (0.614, 0.752)], and the sensitivity and specificity was 51.85% and 78.48%, respectively (P = 0.0008). The AUC of D-dimer + PLT combination was 0.656 [95% (0.582, 0.724)], and the sensitivity and specificity was 62.82% and 65.82%, respectively (P = 0.0086).
Table 3
Diagnostic value of combination of the single index (D-dimer, FIB, WBC, NEU) and PLT or CRP
for in-hospital mortality.
Variable
|
AUC
|
SE
|
95% CI
|
Sensitivity
|
Specificity
|
P value
|
D-dimer + PLT
|
0.656
|
0.0592
|
0.582 to 0.724
|
62.96
|
65.82
|
0.0086
|
FIB + PLT
|
0.722
|
0.0565
|
0.651 to 0.785
|
59.26
|
80.38
|
0.0001
|
WBC + PLT
|
0.584
|
0.0612
|
0.509 to 0.656
|
85.19
|
32.91
|
0.1716
|
NEU + PLT
|
0.571
|
0.0612
|
0.496 to 0.644
|
85.19
|
32.28
|
0.2449
|
D-dimer + CRP
|
0.686
|
0.0556
|
0.614 to 0.752
|
51.85
|
78.48
|
0.0008
|
FIB + CRP
|
0.613
|
0.0625
|
0.539 to 0.684
|
55.56
|
74.68
|
0.0699
|
PLT + CRP
|
0.680
|
0.0622
|
0.608 to 0.747
|
51.85
|
80.38
|
0.0037
|
WBC + CRP
|
0.631
|
0.0533
|
0.557 to 0.701
|
96.30
|
32.28
|
0.0139
|
NEU + CRP
|
0.647
|
0.0517
|
0.573 to 0.715
|
59.26
|
70.89
|
0.0046
|
PLT, platelet; FIB, fibrinogen; WBC, white blood cells; NEU, neutrophil; CRP, C reactive protein. |
Table 4
Predictors of in-hospital mortality in patients with type A AAD by logistic regression.
Variable
|
Univariable
|
Multivariable
|
|
OR
|
95% CI
|
P value
|
OR
|
95% CI
|
P value
|
Age
|
1.106
|
0.752–1.625
|
0.610
|
|
|
|
Sex
|
0.895
|
0.315–2.546
|
0.835
|
|
|
|
BMI
|
1.180
|
0.95–1.466
|
0.135
|
|
|
|
WBC
|
1.742
|
1.095–2.772
|
0.019
|
1.645
|
1.017–2.659
|
0.042
|
Hb
|
1.013
|
0.601–1.708
|
0.961
|
|
|
|
CRP
|
1.069
|
0.837–1.364
|
0.593
|
|
|
|
D-dimer
|
1.530
|
1.123–2.085
|
0.007
|
1.471
|
1.075–2.014
|
0.016
|
FIB
|
0.615
|
0.388–0.975
|
0.039
|
|
|
|
PLT
|
0.988
|
0.978–0.997
|
0.013
|
|
|
|
NEU
|
1.108
|
1.011–1.213
|
0.028
|
|
|
|
BMI, body mass index; WBC, white blood cells; Hb, hemoglobin; CRP, C reactive protein; FIB, fibrinogen; PLT, platelet; NEU, neutrophil. |
As shown in Fig. 3, Patients were divided into two groups according to the optimal critical value of D-dimer (> 10.3 g/L). Of the 132 patients in the low D-dimer group, 10 (7.6%) died during hospitalization. In contrast, of the 74 patients in the high D-dimer group, 18 (24.3%) died during the hospital stays. Chi-square test showed a significant difference in mortality between the two groups (P = 0.002). For FIB, patients were divided into two groups according to the optimal critical value (< 2.12 g/L). Of the 64 patients in the low FIB group, 16 (25.0%) died during hospitalization. In contrast, of 142 patients in the high FIB group, only 12 (8.5%) died during the hospital stays. Chi-square test showed a significant difference in mortality between the two groups (P = 0.002). For PLT, patients were divided into two groups according to the optimal cut-off value (< 122×109/L). Of the 38 patients in the low PLT group, 13 (34.2%) died during hospitalization. In contrast, of the 168 patients in the high PLT group, only 15 (8.9%) died during the hospital stays. Chi-square test showed a significant difference in mortality between the two groups (P = 0.001). For WBC, patients were divided into two groups according to the optimal critical value
(> 13.17×109/L). Of the 148 patients in the low WBC group, 13 (8.8%) died during the hospital stays. In contrast, of the 58 patients in the high WBC group, 15 (25.9%) died during hospitalization. Chi-square test showed a significant difference in mortality between the two groups (P = 0.002). For NEU, patients were divided into two groups according to the optimal critical value (> 11.94×109/L). Of the 152 patients in the low NEU group, 13 (8.6%) died during the hospital stays. In contrast, of the 54 patients in the high NEU group, 15 (27.8%) died during hospitalization. Chi-square test showed a significant difference in mortality between the two groups (P = 0.001).
3.3 Logistic Regression Methods
Logistic regression methods were further used to analyze the independent risk factors for postoperative in-hospital deaths of patients with type A AAD. Univariate Logistic regression analysis showed that the P values of D-dimer, FIB, PLT, WBC and NEU were all less than 0.1, which may be risk factors for postoperative in-hospital deaths of patients with type A AAD (Table 4). In order to exclude the influence of possible confounding factors, multivariate logistic stepwise regression analysis was conducted to identify the independent risk factors. It was found that WBC and D-dimmer were independent risk factors for postoperative in-hospital deaths of patients with type A AAD.